Category: Biology

Control of Expression Random Retrieval

This quiz contains all the questions in the Control of Expression section. The website will pick 20 questions at random.

1 / 20

If you start with a single copy of template DNA, how many copies would you have after 10 cycles?

200

512

1024

2 / 20

What enzyme is needed in a PCR reaction ?

DNA polymerase

RNA polymerase

DNA Ligase

DNA Helicase

3 / 20

We cannot see the proteins made by recombinant plasmids, nor the plasmids themselves. How do we know the bacteria have been transformed properly and contain a recombinant plasmid ( = plasmid and new gene fragment) ?

Structural genes

Marker genes

Mutant genes

Complementary Genes

4 / 20

If a bacterium contains a recombinant plasmid, then it will express the new 'foreign' gene as well as it's own. Which of the following is not a product made by recombinant bacteria?

Human Insulin for Diabetics

Clotting Factors for Haemophiliacs

Enzymes for use in Cheese making

Glycogen for use by atheletes before endurance events.

5 / 20

Which enzyme can join two complementary sticky ends together during genetic modification?

DNA polymerase

DNA Helicase

DNA Restriction Endonuclease

DNA Ligase

6 / 20

What do we call enzymes that cut DNA at specific base sequences?

Restriction Endonucleases

Restriction Hydrolases

Restriction Ligases

Restriction Exonucleases

7 / 20

What effect will increased acetylation have on a gene?

Increase expression

Decrease expression

Stay at a steady level

Stay at whatever it was before.

8 / 20

iPS cells can be made from adult somatic cells. What are somatic cells?

All human cells.

All human body cells except gametes.

All human body cells except unipotent stem cells.

All human body cells except multipotent and unipotent stem cells.

9 / 20

What word describes the inner cell mass now?

Totipotent

Pluripotent

Multipotent

Unipotent

10 / 20

Which term is used to describe the full process of genetic code in DNA being turned into a polypeptide chain?

Gene Repression

Gene Expression

Gene Activation

Gene Mutation

11 / 20

What do we call a transcription factor that 'turns off ' genes?

Repressor

Stopper

Demoter

Suppressor

12 / 20

Which of the following would NOT increase your exposure to oestrogen?

Starting menstruation (Periods) early.

Hormone Replacement Therapy ( HRT).

Starting menstruation (periods) late.

Starting the menopause ( end of periods) late.

13 / 20

If hypomethylation ( reduced methylation) happens to a tumour suppressor gene what effect will this have on the rate of mitosis?

Increase

Decrease

Stay the same

14 / 20

Fill in the missing word : Causes of Mutations A mutation is any change to the order of __12___ in the genetic code. These occur naturally as the enzyme _____13_____ replicates the DNA and makes mistakes. The incidence can also be produced due to exposure to certain agents called mutagenic agents.

These can be chemicals such as nitrous acid, which converts cytosine to uracil. Nitrous acid would therefore cause a __14___ mutation. Ethidium Bromide is used to stain DNA during gel electrophoresis. It can insert between bases, acting in a similar way to an addition mutation and therefore causing a __15___ along the rest of the gene.

UV radiation is also a mutagenic agent. It can cause bonds to form between pyrimidine bases ( thymine and cytosine). This bonding causes polymerases to misread or stop working all together at that point.

Deletion

Substitution

Inversion

Translocation

15 / 20

It can cause bonds to form between pyrimidine bases ( thymine and cytosine). This bonding causes polymerases to misread or stop working all together at that point.

DNA polymerase

DNA ligase

DNA Helicase

DNA Endonuclease

16 / 20

What type of mutation causes a sequence of bases to be reversed?

Substitution

Addition

Deletion

Inversion

17 / 20

Which word describes the sequence of three bases on DNA that code for an amino acid?

Codon

Anti-Codon

Codelet

Triplet

18 / 20

Which of the following is a difference between prokaryotic and eukaryotic DNA?

Contains 4 bases : A,T, C and G

Uses DNA polymerase to replicate

DNA is wrapped around histone proteins

H bonds hold the complementary base pairs together

19 / 20

Each complementary strand of DNA runs in opposite directions. What word describes this?

Counter-current

Parallel

Anti-Parallel

Anti - Prime

20 / 20

Name the components of a DNA nucleotide.

Phosphate, Ribose and Base

Phosphate, Deoxyribose and Base

Phosphate, Deoxyribose and Acid

Potassium, Deoxyribose and Base

Your score is

Populations, Evolutions & Genetics Random Retrieval

This quiz contains all the questions in the Populations, Evolutions & Genetics section. The website will pick 20 questions at random.

1 / 20

Between stages D and E, what will happen to light intensity at ground level?

Increase

Decrease

2 / 20

At which stage will abiotic factors be most hostile?

3 / 20

True or false : Succession involves only the change of biotic factors ( Not abiotic).

TRUE

FALSE

4 / 20

True or false : Succession is the same as evolution.

TRUE

FALSE

5 / 20

What should you use to estimate a population of a sessile organism?

A Net

A Pitfall Trap

A meter ruler

A Quadrat

6 / 20

What would you press to show a bacterial population graph , plotted with a log 10 scale, back into actual bacterial population?

By using 10 ^x

By using x ⁿ

By pressing 'log ₁₀'

By pressing 'Inverse log ₁₀'

7 / 20

Which of the following is an abiotic factor which effects population size?

An increase in a wolf population, leads to a decrease in hare populations.

A new pathogen causes a decrease in a rabbit population.

Less light falling on leaves, so less photosynthesis and less glucose produced for growth.

An increase in aphids means more food for ladybirds.

8 / 20

What is the word used to describe 'Populations of different species in specific habitat'?

Niche

Community

Population

Ecosystem

9 / 20

An alteration in bird calls caused by difference in beak size, preventing mating calls between individuals of the same population is an example of what type of speciation?

Allopatric

Parapatric

Peripatric

Sympatric

10 / 20

What type of variation is show in the graph?

Directional

Disruptive

Stabilising

11 / 20

Which type of selection is shown by Darwins finches, where small and large beaks were both at an advantage due to different food sources?

Directional

Disruptive

Stabilising

12 / 20

The probability of an individual having Cyctic Fibrosis is about 1 in 2500 in the UK. What proportion of the population will be carriers?

0.0007

0.039

0.5

0.0004

13 / 20

Drosophila fruit flies can have either vestigial wings (w)or wild-type wings (W). If 20% of the population have vestigial wings, what proportion of the population are homozygous dominant?

0.31

0.64

0.8

0.44

14 / 20

Which part of the Hardy Weinberg equation represents the homozygous recessive individuals?

p²

q²

15 / 20

What is the formula for the Hardy Weinberg equation?

p² + pq + q² = 1

2p + pq ² + 2q = 1

p² + 2pq + q² = 1

p² + 2 pq + q ²= 0

16 / 20

What is the definition of a species?

A group of similar organisms

A group of similar organisms which can reproduce to make offspring.

A group of similar organisms which can reproduce to make fertile offspring.

A group of similar organisms that can reproduce to make hybrids.

17 / 20

How can you tell if two alleles are autosomally linked?

The phenotypic ratio is equal to the expected Mendelain ratio.

The Phenotypic Ratio is always greater than the expected Medelian ratio.

The Phenotypic ratio is different to the Mendelian ratio.

The male children always show the trait.

18 / 20

Why are women far less likely to show sex linked disorders?

Because they don't have Y chromosomes which carry the disorder allele.

Because they have faster acting immune systems.

Because they have two X chromosomes, one is likely to be a healthy dominant allele and masque the recessive disorder one.

Because they are less likely to moan about it and so not get diagnosed.

19 / 20

Which Chromosome contains more genes?

20 / 20

Marfan Syndrome ( TGF Beta) is dominant (T) to the healthy recessive allele(t) . Having a V shaped hairline (V) is dominant to having a straight hairline (v). What percentage of the offspring of a father = TtVv and a mother TtVv will have Marfan syndrome and a V shaped hair-line ?

56.25%

12.5%

6.25%

18.75%

Your score is

Responding to Change Random Retrieval

This quiz contains all the questions in the Responding to Change section. The website will pick 20 questions at random.

1 / 20

Which of the following is a feature of fast twitch muscle fibres when compared to slow twitch.

Fewer blood vessels

Higher numbers of mitochondria

Lower concentration of PCr.

2 / 20

Breaks down ATP on myosin head

ATPase

ATP Synthase

Calcium ions

3 / 20

Name the molecule that carries out the function : Attaches to the Z line at the end of the sarcomere.

Actin

Myosin Tails

Myosin Heads

4 / 20

Which of the above diagrams represents the myofilaments an 'M line' in muscle?

5 / 20

Name part B on the above diagram (type your answer).

6 / 20

Can the potential difference created by a receptor have different values depending on the size of the stimulus?

Yes

7 / 20

What term is used to describe when more than one presynaptic neurone releases its neurotransmitter onto single post-synaptic neurone? ( Type your answer carefully)

8 / 20

What reduces the concentration of neurotransmitter in a synapse after it has diffused across?

The neurotransmitter is actively reabsorbed whole, via endocytosis.

An enzyme breaks the neurotransmitter down.

Nothing, it just diffuses until a vey low concentration is reached.

9 / 20

Axons with a wider diameter axon have...

More sodium ions for diffusion.

More resistance to the flow of ions through the cytoplasm.

Less resistance to the flow of ions through the cytoplasm.

10 / 20

Name the term given to the 'jumping' of an action potential long a myelinated neurone.( Type in your answer)

11 / 20

Cells wrapped around peripheral neurones contain a membrane with a high content of a fatty substance forming a sheath.

What is the name of this fatty substance? ( Type your answer).

12 / 20

True or false: If more sodium channels are opened by a stimulus, then the action potential which is generated is bigger.

TRUE

FALSE

13 / 20

Why can't a second action potential pass immediately after the first ?

During this period the Sodium-potassium pump is not operational.

During this period the voltage gated sodium channels are locked shut.

During this period the potentil difference across the plasma membrane remains positive.

14 / 20

When an neurone axon is at rest, what charge is the extra cellular fluid compared to the cytoplasm?

a) Simple Diffusion
b) Facilitated Diffusion
c) Active Transport

Positive

Negative

Neutral

15 / 20

Mica is like thin glass, and is impermeable to most substances. What does Boysen Jensen's experiment inserting mica show ?

That chemicals diffuse down the shoot from the tip.

That chemicals move away from light.

That chemicals move away from light and diffuse down from the tip.

16 / 20

What does this experiment by Went show?

That uneven distribution of a chemical from a shoot tip controls growth.

That even distribution of a chemical from a shoot tip controls growth.

That gelatin controls growth.

17 / 20

What does Darwin's experiment where he placed a black cover over the tip show?

That directional light on the tip effects the direction of growth.

That directional light does not effect direction of growth.

That aluminium foil is toxic to shoot tips.

18 / 20

In shoot tips which are lit from the side, where will the highest concentration of IAA be found?

The lit side ( illuminated)

The shaded side

Both sides evenly

19 / 20

How does IAA bring about this effect?

Stimulates reactions to increase the amount of cellulose in the cell wall, so it can grow.

Stimulates reactions to make the membrane more fluid.

Stimulates reactions which break the bonds between the cellulose molecules in the cell wall.

20 / 20

What response do roots have to light?

Negatively Geotrophic

Positively Phototrophic

Negatively Phototrophic

Your score is

The Transfer of Energy Random Retrieval

This quiz contains all the questions in the The Transfer of Energy section. The website will pick 20 questions at random.

1 / 20

Some fungi form symbiotic relationships with plant roots. What are these fungi/root structures called?

Mycorhizobia

Mycoprotein

Mycorrhizae

2 / 20

If N = Net productivity, F = Energy in food, U = Energy lost in Faeces and Urine, R = Energy lost in Respiration. What would be the formula for Net productivity?

N = F (U + R)

N = F + (U - R)

N = F - (U + R)

3 / 20

What is the formula for NPP?

NPP = GPP - R

NPP = GPP + R

NPP = R - GPP

4 / 20

The student found that the coloured liquid moved 1.5 cm in 24 hours. The diameter of the lumen (hole) of the capillary tubing was 1 mm.The volume of a capillary tubing is given by πr²l, where π is 3.14 and l = length. Calculate the volume of gas produced in cm³ hour^-1.

4.91 x 10-4

1.17 x 10-3

2.45 x 10-3

5 / 20

The diagram represents anaerobic respiration, name substance 'Z'.

Lactic Acid

Pyruvic Acid

Ethanol

6 / 20

The diagram represents anaerobic respiration, name substance 'W'.

Reduced NAD

Carbon Dioxide

ADP

7 / 20

Is the column for glycolysis in the above diagram correct?

Yes

8 / 20

How many molecules of reduced NAD ( or NADH) are generated in aerobic respiration from one molecule of glucose?

9 / 20

How many molecules of Y will be produced by the krebs cycle from a single molecule of glucose?

10 / 20

What is represented by molecule D?

Acetyl Co A

Co A

Carbon dioxide

11 / 20

What happens to triose phosphate when it is converted to molecule X?

Triose phosphate is oxidised

Triose phosphate is reduced

Triose phosphate is phosphorylated

12 / 20

The solution in the above experiment had the same water potential, why is this important?

To prevent cell lysis by osmosis

To prevent cell damage by denaturing.

To prevent chloroplast lysis by osmosis

13 / 20

How many atoms of carbon in ONE molecule of substance C?

14 / 20

How many carbon atoms are there in ONE molecule of substance B?

15 / 20

Name substance D

Carbon Dioxide

Ribulose bisphosphate

Hexose sugar

16 / 20

Which chemical does 'E' represent?

NAD

NADP

NADPH

17 / 20

What is structure D?

PS1

PS2

PS3

18 / 20

What type of molecule is represented by 'C'?

Photosystems

ATP Synthase

Electron Carriers

19 / 20

Which letter represents a lamella?

20 / 20

Name structure B

Your score is

Biology Year 13 Random Retrieval

This quiz contains all the questions in the year 13 biology section. The website will pick 20 questions at random.

1 / 20

What effect will having a high methylation of a promoter sequence , have on expression of that gene?

Increase

Decrease

Stay at a steady level

Stay at whatever it was before

2 / 20

What do we call a transcription factor that 'turns off ' genes?

Repressor

Stopper

Demoter

Suppressor

3 / 20

The mRNA travels to the ribosome, where it feeds between the two subunits, exposing the template bases. tRNA molecules each carry a specific amino acid at the top, with a complementary sequence of three bases called an anti-codon at the bottom. The tRNA anticodons then complementary base pair with the mRNA codon. In the ribosome there are 3 binding sites for tRNA, two where a peptide bond is formed between the carried amino acids.

These amino acids then form a ____10_____ chain which leaves the ribosome. The third site is a departure site, where the tRNA which has released its amino acid departs to pick up a new amino acid. Once the entire mRNA sequence has been ____11____, it can either pass into another ribosome to make another polypeptide or be degraded.

Polypeptide

Polynucleotide

Polysaccharide

Phospholipid

4 / 20

The deoxyribose sugar at the end of a DNA molecule can either have a bond available to join with carbon number 3 ( 3' or 3 prime) or carbon number 5 (5' or 5 prime). DNA polymerase can only join to one end, which end can it bind to and then extend?

5' (5 prime)

3' (3 prime)

5 / 20

Which of the following is NOT a difference between RNA and DNA?

Single stranded/Double stranded

Not made out of nucleotides/ made out of nucleotides

Uracil/Thymine

No Introns/Introns

6 / 20

True or False : Two different species cannot occupy the same niche?

TRUE

FALSE

7 / 20

In peppered moths, having light coloured wings is dominant. In Sheffield (an industrial northern town in the UK) a sample of moths was taken. The numbers collected were 73 light coloured , and 326 dark coloured. What proportion of all alleles are for the dark one?

0.904

0.817

0.174

0.991

8 / 20

What would be the genotype for a man with colour-blindness (b)?

Xb Yb

Xb Y

XB Yb

XB YB

9 / 20

Which of the following are features of slow twitch muscle fibres:

A)Lots of aerobic respiration
B)Lots of mitochondria
C)Low levels of myoglobin

A & C

A & B

A, B & C

10 / 20

The table shows the results on investigating how fast an anaesthetic works. Using the results from the machine, was there a significant difference between anaesthetics S and Q?

Yes

11 / 20

Why is the speed of conduction faster on myelinated neurones?

The sheath creates a hydrostatic pressure, pushing the ions and therefore the action potential along.

The sheath keeps the axon warmer, therefore diffusion is faster.

Due to action potentials only occurring at the gaps between the sheath, so the impulse 'jumps' between them.

12 / 20

Which of the events ( A- F above) requires ATP ? ( Type the letter in the box)

13 / 20

What causes a change in the type of channels that are open at stage '4' ?

A change in potential difference.

The passage of 1.5ms since the stimulation occurred.

The generation of a second action potential.

14 / 20

Which direction are the ions moving during process 3 on the above diagram?

Into the cytoplasm

Out of the cytoplasm

15 / 20

In a resting neurone, why do potassium ions move out via ion channels?

Due to the greater concentration on potassium ions on the inside compared to the outside.

Due to the electrochemical gradient.

Due to the lower concentration on potassium ions on the inside compared to the outside.

16 / 20

Which of these statements about Went's experiment is NOT true?

That plant growth is probably caused by a chemical which can diffuse.

That a substance produced in the tip can move (diffuse) into gelatin, and then out again.

Gelatin blocks stimulate growth.

17 / 20

Which of the following is true?

If IAA is unevenly distributed, then growth is evenly distributed and the tissue grows straight. If IAA is evenly distributed, the growth is uneven and the tissue bends.

If IAA is evenly distributed, then growth is evenly distributed and the tissue grows straight. If IAA is unevenly distributed, the growth is uneven and the tissue bends.

18 / 20

What would be the most appropriate units for measuring biomass?

kJ m^-2

Kg m^-2

19 / 20

In this investigation, are the yeast respiring anaerobically or aerobically ?

Anaerobically

Aerobically

20 / 20

Why can it be advantageous to a plant for more of process 'G' to occur?

More ATP is synthesised

More reduced NADP is synthesised

More Glucose is synthesised

Your score is

Biology Random Retrieval Y13

Biology Year 13 Random Retrieval

This quiz contains all the questions in the year 13 biology section. The website will pick 20 questions at random.

1 / 20

If a tumour suppressor gene mutates, then it can mean the protein it codes for is non-functional. What will happen to the rate of mitosis if this happens?

Increase

Decrease

Stay the same

2 / 20

What word describes when a mutation causes all the following triplet codes to be misread in a different frame?

Non-disjunction

Frameshift

Reading Shift

Triplet Misread.

3 / 20

Which component of a nucleotide contains nitrogen atoms?

Phosphate

Ribose

Deoxyribose

Organic Base

4 / 20

What is lichen made out of ?

Single celled plants.

Fungus.

Fungus and Algae.

5 / 20

What do we call a stage of succession?

Serial

Sere

Generation

6 / 20

What would you press to show a bacterial population graph , plotted with a log 10 scale, back into actual bacterial population?

By using 10 ^x

By using x ⁿ

By pressing 'log ₁₀'

By pressing 'Inverse log ₁₀'

7 / 20

Is predation a biotic or abiotic factor that effects population size?

Biotic

Abiotic

8 / 20

Is the following an 'Abiotic adaptation' or a 'Biotic Adaptation': The Warbler Finch has a short slender beak for catching insects whilst, flying. Where as the Large Ground Finch has a strong , deep beak for crushing seeds.

Abiotic Adaptation

Biotic Adaptation

9 / 20

What is the structural adaptation which gives rods high sensitivity compared to rod cells?

Single rod cells synapse with a single bipolar neurone.

Many rod cells can synapse with a single bipolar neurone.

The pigment in cones ( Photopsin) is less sensitive than that in rods (Rhodopsin).

10 / 20

The diagram above shows a cross section of a human eye. Name layer A (Type your answer).

11 / 20

When the layers of connective tissue are pressed, what happens to the neurone membrane?

It becomes more negative on the outside.

It becomes more positive on the outside.

It becomes more negative on the inside.

12 / 20

Whether a synapse is excitatory or inhibitory depends on what?

The concentration of the neurotransmitter released.

The type of neurotransmitter released.

The concentration of calcium ions.

13 / 20

True or False: Synapses can only transmit an impulse in one direction?

TRUE

FALSE

14 / 20

Axons with a wider diameter axon have...

More sodium ions for diffusion.

More resistance to the flow of ions through the cytoplasm.

Less resistance to the flow of ions through the cytoplasm.

15 / 20

Cells wrapped around peripheral neurones contain a membrane with a high content of a fatty substance forming a sheath.

What is the name of this fatty substance? ( Type your answer).

16 / 20

Name the process happening at '4' on the above diagram?

Depolarisation

Polarisation

Repolarisation

17 / 20

The diagram shows a food web found in the arctic. the producers have a net productivity of 4.52 x 10 ^-3 kJ m^-2yr^-1-2yr^-1

0.9865

0.0135

0.135

18 / 20

How many molecules of reduced NAD ( or NADH) are generated in aerobic respiration from one molecule of glucose?

19 / 20

How many molecules of H are required to produce one molecule of glucose?

20 / 20

Which term best describes what happens to the electrons when light hits the primary pigment (or reaction centre)?

Animated

Excited

Activated

Your score is

The Transfer of Energy Random Retrieval

This quiz contains all the questions in the The Transfer of Energy section. The website will pick 20 questions at random.

1 / 20

What is 'Guano'?

The waste product excreted from birds.

Dead Sea Birds.

Both the waste product and dead sea birds.

2 / 20

The above diagram shows the phosphorus cycle. Name process B

Decomposition

Sedimentation

Weathering

3 / 20

Which process can occur due to the actions of Nitrosomonas bacteria?

4 / 20

Which term describes an organism which feeds on dead organic matter and digests their food externally? (watch your spelling)

5 / 20

It has been estimated that an area of 8000m² is needed to keep a cow. The productivity of grass in the UK is 18,000 kJ m^-2yr^-1

0.0833

0.0096

0.0104

6 / 20

Which would be the most accurate method of sampling dry biomass?

Burning the sample in a calorimeter in the presence of oxygen.

Taking the mass of the sample, then drying in an oven at a very low temperature, until the mass remains constant.

Taking the mass of the sample, then drying in an oven at a very high temperature, until the mass remains constant.

7 / 20

Which direction would the bubble move in the above experiment?

Left ( towards the flask)

Right (away from the flask)

8 / 20

The ETC develops a proton gradient as the electrons pass through. What is the process of these protons moving down an electrochemical gradient called?

9 / 20

Name molecule 'Z'

10 / 20

Which part of the mitochondria is represented by A?

Matrix

Intermembrane space

Inner Membrane

11 / 20

Isocitrate dehydrogenase is an enzyme used in the Krebs cycle to convert Citrate into the 5C intermediate. IDH1 is an inhibitor of Isocitrate dehydrogenase. If IDH1 acted as a competitive inhibitor of the enzyme, how would it reduce enzyme activity?

By binding to an allosteric site, altering the tertiary structure of the active site, making it non-complementary to substrates.

By binding to the active site, changing the tertiary structure and therefore making it non-complementary to the substrate.

By blocking the active site, thereby reducing the formation of enzyme-substrate complexes.

12 / 20

Isocitrate dehydrogenase is an enzyme used in the Krebs cycle to convert Citrate into the 5C intermediate. IDH1 is an inhibitor of Isocitrate dehydrogenase. What would happen to the volume of Carbon dioxide produced by cells exposed to IDH1?

Increase

Decrease

Stay the same

13 / 20

If 3 million molecules of glucose are respired aerobically, how many molecules of CO₂ will be produced by the Krebs Cycle?

3 million

6 million

12 million

14 / 20

Which molecule is represented by Y?

NADP

Reduced NAD

NAD+

15 / 20

What happens to molecule Y during the conversion of triose phosphate to molecule X?

Y is phosphorylated

Y is oxidised

Y is reduced

16 / 20

How many carbons are present in hexose bisphosphate?

17 / 20

What is the first process to happen in glycolysis?

Phosphorylation of glucose

Methylation of glucose

Hydrogenation of glucose

18 / 20

True or False - Using a different solvent does not alter the distance travelled by different substances in this technique?

TRUE

FALSE

19 / 20

In the above experiment, a 'starting line' is drawn in pencil. What is the name of the starting line - The ______(spell it correctly!)

20 / 20

Name structure E

Your score is

Responding to Change Random Retrieval

This quiz contains all the questions in the Responding to Change section. The website will pick 20 questions at random.

1 / 20

Which of the following are features of slow twitch muscle fibres:

A)Lots of aerobic respiration
B)Lots of mitochondria
C)Low levels of myoglobin

A & C

A & B

A, B & C

2 / 20

What is the role of phosphocreatine in muscle contraction?

As a respiratory substrate to feed into glycolysis.

Hydrolysis of ATP

Phosphorylation of ATP

3 / 20

When light falls on cells 1 and 2, only one spot of light is seen. But, when light falls on cells 2 and 3, two spots of light are seen. Say why?

1 & 2 share a neurone, and 2 and 3 share a neurone.

1 & 2 share a neurone, and 2 and 3 have separate neurones.

2 and 3 are both cone cells.

4 / 20

The cone density is highest on the fovea in the centre of the retina. In a human fovea there are 150 000 cones per mm2. The diameter of a human fovea is 1.2 mm. Calculate the number of cones on the human fovea.

678584

239790

169646

5 / 20

Name part B on the above diagram (type your answer).

6 / 20

The table shows the results on investigating how fast an anaesthetic works. Using the results from the machine, was there a significant difference between anaesthetics S and Q?

Yes

7 / 20

Synaptic knobs contain mitochondria, which of the following is NOT a use of ATP in the presynaptic neurone?

To pump calcium ions out of the pre-synaptic membrane.

To make the vesicles fuse with the presynaptic membrane.

To reabsorb degraded neurotansmitter.

8 / 20

On the diagram, which type of ion will D allow through when opened on an excitatory synapse?

Sodium ions

Potassium ions

Calcium ions

9 / 20

Once an action potential has been generated, why is the wave of depolarisation only in one direction?

Hyperpolarisation means potassium channels are working at capacity.

Sodium ions only ever diffuse away from the cell body.

The refractory period means that voltage gated channels are 'locked' closed.

10 / 20

Many peripheral neurones (including motor neurones)have cells wrapped around the axon.

What are these cells called? ( type your answer- watch your spelling).

11 / 20

Why can't a second action potential pass immediately after the first ?

During this period the Sodium-potassium pump is not operational.

During this period the voltage gated sodium channels are locked shut.

During this period the potentil difference across the plasma membrane remains positive.

12 / 20

In a resting neurone, why do potassium ions move out via ion channels?

Due to the greater concentration on potassium ions on the inside compared to the outside.

Due to the electrochemical gradient.

Due to the lower concentration on potassium ions on the inside compared to the outside.

13 / 20

The plasma membrane of a neurone at rest is most permeable to which ions via facilitated diffusion?

Chlorine ions

Sodium Ions

Potassium Ions

14 / 20

Across a resting human neurone plasma membrane, what is the average potential difference?

+70mV

-70mV

-70V

15 / 20

In the above experiment, you hypothesised that a woodlouse responds by kinesis to a change in light intensity. What would be the best way to measure a response which shows kinesis?

By putting them on the lighter side, and seeing if they move to the darker side.

By counting how many woodlice are on the dark side after on minute.

By measuring how often each woodlice turns/ changes direction in one minute.

16 / 20

Woodlice are more stationary with increased humidity. Is this taxis or kinesis?

Taxis

Kinesis

17 / 20

What does Darwin's experiment where he placed a black cover over the tip show?

That directional light on the tip effects the direction of growth.

That directional light does not effect direction of growth.

That aluminium foil is toxic to shoot tips.

18 / 20

What does Darwin's experiment where he removed a shoot tip then replaced it show?

That the shoot tip is not needed for shoot growth.

That the shoot tip is responsible for shoot growth.

That growth is controlled below the shoot tip.

19 / 20

Which of the following is an example of a plant growth factor?

Indyacetic Acid

Indoleacetic Acid

Indayloacetic Acid

20 / 20

Plant responses to stimuli are controlled by what?

Photosynthesis

Growth Factors

Action Potentials

Your score is

Populations, Evolutions & Genetics Random Retrieval

This quiz contains all the questions in the Populations, Evolutions & Genetics section. The website will pick 20 questions at random.

1 / 20

What is it called when succession is stopped artificially?

Plagioclimax

Counterclimax

Hoaxclimax

2 / 20

Between stages D and E, what will happen to light intensity at ground level?

Increase

Decrease

3 / 20

Between stages B and C, what will happen to soil depth?

Increase

Decrease

4 / 20

What is lichen made out of ?

Single celled plants.

Fungus.

Fungus and Algae.

5 / 20

What term do we use to describe lichen and mosses in succession?

Frontier

Pioneer

Cavalier

6 / 20

Which of the following is an example of primary succession?

Volcanic eruption and lava flow creates new rock.

Ploughing a field.

Burning rain forest to clear scrub exposes soil.

7 / 20

Which method would you use to see if there is a correlation between profile height and percentage cover of marsh grass?

Random sampling

An interrupted belt transect

Mark Release Recapture

8 / 20

You can also use a transect to sample a population. When should a transect be used?

To estimate a population in a square area, e.g. High Light Intensity, compared to low light intensity.

To estimate a population of motile organisms using a net.

To measure a population, along a change in a factor, e.g. Light Intensity

To physically cut up a sample to see its internal organs.

9 / 20

Abiotic Adaptation

Biotic Adaptation

10 / 20

What is the word used to describe 'The specific role of a species within its habitat'?

Niche

Community

Population

Ecosystem

11 / 20

What type of speciation is caused by a physical barrier between two populations such as a body of water?

Allopatric

Parapatric

Peripatric

Sympatric

12 / 20

Which type of selection is shown by fossils of black bears, showing them becoming bigger during glacial periods ( ice ages)?

Directional

Disruptive

Stabilising

13 / 20

Natural Selection is when organisms which are better adapted are more likely to survive and pass on their genes. Factors which affect the chance of survival are called selection pressures. These can be positive ( advantageous) or negative ( disadvantageous). Which of these is a negative selection pressure?

Competition for Food

Plenty of food

Big Territory

Successful Reproduction

14 / 20

What is 'crossing over'?

When the spindle attaches to the centromere.

When a spontaneous mutation occurs.

When the chromosomes become visible during prophase.

When the homologous chromosomes wrap around each other, break, and re-attach to the opposite chromosome.

15 / 20

Which part of the Hardy Weinberg equation represents the homozygous recessive individuals?

p²

q²

16 / 20

A group of organisms of the same species living in a particular area at a particular time' is the definition for what?

Community

Population

Habitat

Niche

17 / 20

Which statistical test would we use to see if the observed phenotypes are different from the expected phenotypes?

Standard Deviation

Students' t Test

Spearmanns Rank

Chi Squared

18 / 20

What is an autosome?

Self replicating chromosome

All Chromosomes

All Chromosomes except the sex chromosomes

Only the Sex Chromosomes

19 / 20

Marfan syndrome is a dominant inherited disorder, where the suffer develops an increase in a growth factor ( TGF - beta) which effects connective tissue. What is the probability of a healthy mother and a heterozygous father having a healthy child?

0.75

0.5

0.25

20 / 20

In Guinea pigs, ginger(G) hair is dominant to white(g), and short hair (S) is dominant to long (s). In the following cross: GgSs and GgSS, what percentage chance will the offspring being born long haired and ginger?

0.25

0.19

0.06

Your score is

Control of Expression Random Retrieval

This quiz contains all the questions in the Control of Expression section. The website will pick 20 questions at random.

1 / 20

Usually the cut out gene is inserted into a vector. Which of the following is a vector for use in genetic modification of bacteria?

Mosquito

Plasmid

Rat

E Coli

2 / 20

If the same restriction enzyme is used to make two fragments, what can form between the exposed bases on each end if they are mixed with each other?

Glycosidic bonds

Peptide bonds

Ester bonds

Hydrogen bonds

3 / 20

Which enzyme do we use to convert mRNA into cDNA?

Reverse Translate

Reverse Transcribase

Reverse Transcriptase

Reverse mRNAase

4 / 20

What causes epigenetic markers to be added or removed from DNA?

Exposure to carcinogens.

Inherited mutations from parents.

Exposure to environmental conditions such as a balanced diet.

Exposure to ionising radiation.

5 / 20

Which type of stem cells are not found in adults?

Pluripotent

Multipotent

Unipotent

Somatic Cells

6 / 20

Which term is used to describe the full process of genetic code in DNA being turned into a polypeptide chain?

Gene Repression

Gene Expression

Gene Activation

Gene Mutation

7 / 20

Oestrogen can act as a transcription factor. To do so, it needs to bind to what molecule?

Oestrogen Active Site

Oestrogen Binding site

Oestrogen Receptor

Oestrogen Trap

8 / 20

In the ribosome there are 3 binding sites for tRNA, two where a ____9____ bond is formed between the carried amino acids. These amino acids then form a ____10_____ chain which leaves the ribosome. The third site is a departure site, where the tRNA which has released its amino acid departs to pick up a new amino acid.

Once the entire mRNA sequence has been ____11____, it can either pass into another ribosome to make another polypeptide or be degraded.

Base

Codon

Anti-codon

Amino acid

9 / 20

What is the difference between mRNA and pre-mRNA?

Amino acids joined by peptide bond

Nucleotides joined by a phosphodiester bond

Exons removed

Introns removed

10 / 20

If hypomethylation (reduced methylation) happens to a proto-oncogenes gene, what effect will this have on the rate of mitosis ?

Increase

Decrease

Stay the same

11 / 20

Methylation of DNA is when a methyl group ( CH3) is added onto CpG bases ( cytosine and guanine next to each other). This can stop DNA polymerase from binding.

What effect will increased methylation (Hypermethylation) have on transcription?

Increase

Decrease

Stay the same

12 / 20

The incidence can also be produced due to exposure to certain agents called mutagenic agents. These can be chemicals such as nitrous acid, which converts cytosine to uracil. Nitrous acid would therefore cause a __14___ mutation. Ethidium Bromide is used to stain DNA during gel electrophoresis. It can insert between bases, acting in a similar way to an addition mutation and therefore causing a __15___ along the rest of the gene.

Amino Acids

Monosaccharides

Polypeptides

Bases

13 / 20

What word describes when a mutation causes all the following triplet codes to be misread in a different frame?

Non-disjunction

Frameshift

Reading Shift

Triplet Misread.

14 / 20

TTA = Leu TTG = Leu TTC = Phe TCA = Ser TAA = Stop Here is the original sequence : TTCTTGTTATCATAA. Here is a mutated sequence: TTCTTGTTATAACATAA.

What will be the effect on the mutated polypeptide?

Shorter

Longer

1 wrong amino acid, but rest in the same order.

1 wrong amino acid, and the rest also wrong amino acids.

15 / 20

TTA = Leu TTG = Leu TTC = Phe TCA = Ser TAA = Stop Here is the original sequence : TTCTTGTTATCATAA. Here is a mutated sequence: TTCTTATTATCATAA.

Will this mutation affect the primary structure of the polypeptide ?

Yes

16 / 20

Which direction can DNA polymerase only extend the new strand of DNA?

5' (5 prime)

3' (3 prime)

17 / 20

Which of the following is NOT a difference between RNA and DNA?

Single stranded/Double stranded

Not made out of nucleotides/ made out of nucleotides

Uracil/Thymine

No Introns/Introns

18 / 20

What does the C stand for in the genetic code?

Cytosine

Cytotine

Cytonine

Cytonide

19 / 20

Name the type of bond that holds the complementary base pairs together.

Hydrogen

Ionic

Glycosidic

Phosphodiester

20 / 20

Name the type of reaction that joins the nucleotides together.

Reduction

Hydrolysis

Condensation

Oxidation

Your score is

Biology Random Retrieval

Year 12

Biology Year 12 Random Retrieval

This quiz contains all the questions in the year 12 biology section. The website will pick 20 questions at random.

1 / 20

During Metaphase 1, the homologous pairs can line up with either the paternal chromosome above, or the maternal chromosome above. What is this phenomenon called?

Recombination

Chiasmata

Independent Segregation

2 / 20

On this diagram, what does D represent?

Locus

Homologous Chromosomes

Centromeres

3 / 20

In eukaryotes, the pre-mRNA is modified by removing what?

Introns

Exons

Start Codons

4 / 20

Which is the true statement about DNA compared to RNA?

They are both double stranded.

They both use the same nucleotides

They are both made out of nucleotides, but RNA contains Uracil not Thymine.

5 / 20

When will the valves close?

When the pressure is lower in front of the valve and higher behind it.

When the pressure is higher in front of the valve, and lower behind it.

When the pressure is equal.

6 / 20

Why might the FEV be lower for person B?

Person B is at rest.

Person A is exercising.

Person B has Asthma.

Person B has Lactose Intolerance.

7 / 20

What is the volume of the same roughly spherical spongy mesophyll cell with a diameter of 80 µm, using the formula Volume=4/3 pi r ³?

2,144,661 µm³

2,144,660µm³

268,082 µm³

268,083 µm³

8 / 20

In the above experiment, two flasks contained identical masses of animal tissue, identical volume of a solution containing sodium ions, but an inhibitor of ATP production in flask F. Scientists concluded that flask G took up sodium ions by active transport. What is the evidence of this?

a) Uptake in flask G much greater than in flask F , showing use of ATP in flask G

b) Sodium ion concentration in flask G falls to zero, showing uptake against a concentration gradient

a & b

9 / 20

In a suspected lung cancer tissue sample, a histopathologist observed 19 cells out of a total of 320 in mitosis. The average mitotic index for healthy human lung tissue is 0.04. Is the patient likely to have cancer or not?

Likely to have Cancer

Not likely to have cancer

10 / 20

Which phase of mitosis is when the chromosomes condense?

Metaphase

Prophase

Anaphase

11 / 20

To look at a fresh sample under a light microscope, you'll need to prepare a temporary mount. What is NOT used to stick the specimen to the microscope slide?

Water

Glue

Oil

12 / 20

Assume the scale bar in this image is 2cm long, what is the magnification of this image?

X 40,000

X 400,000

X 250,000

13 / 20

Which of these structures is completely absent in eukaryotic cells?

14 / 20

What is structure D called?

Nucleus

Plasmid

Nucleosome

15 / 20

Are the bonds between water molecules stronger or weaker than covalent bonds?

Stronger

Weaker

16 / 20

On the above graph, lines A and B represent the same enzyme, in identical conditions; the only difference is the temperature.

What would happen to the red line after this point ?

It would eventually plateau below the black line

It would eventually plateau on the black line.

It would not plateau, but continue straight.

17 / 20

Which word best describes the shape of the substrate?

The same as the active site

Complementary to the Active Site

Opposite to the active site

18 / 20

What is the next reagent to be added after this initial treatment?

Copper Carbonate

Copper Sulphate

Copper Oxide

19 / 20

The animal branched molecule, has many more branches than the plant version. Why is this?

It is insoluble.

It is stronger, and adds to the structure in muscles.

More sites for hydrolytic enzymes to attach, for swift energy release.

20 / 20

How do you convert sucrose (which will test negative for a reducing sugar) , into monosaccharides which will test positive as a reducing sugar?

Add sodium hydrogen carbonate to sucrose solution and heat.

Boil the sucrose solution first, then test for a reducing sugar.

Heat sucrose solution with HCl, then neutralise with sodium hydrogencarbonate. Then test for a reducing sugar.

Your score is

Biology Molecules Random Retrieval

This quiz contains all the questions in the Biology Molecules section. The website will pick 20 questions at random.

1 / 20

Water has a high specific heat capacity, why is this useful to organisms?

It takes a lot of energy to make a little change in temperature, so body temperature is more stable.

It takes a little amount of energy to make a large change in temperature, so body temperature can adapt.

So only a little energy is used to heat up the aqueous cells.

2 / 20

What charge will be on the hydrogen atoms in this molecule?

A full negative charge

A partial Negative charge

A partial positive charge

3 / 20

If DNA replicated by a Dispersive method ( fragments from each strand mixed), what would the DNA bands look like after two generations in N¹⁴ medium (Tube B)?

One band at N¹⁴

One band imbetween N¹⁴, and N¹⁵

Two bands: one at N¹⁵, and one imbetween N¹⁵ and N¹⁴

4 / 20

What type of bond forms between complementary base pairs?

Phosphodiester

Ionic

Hydrogen

5 / 20

Name the pentose sugar found in DNA.

Dioxyribose

Deoxyribose

Dideoxyribose

6 / 20

DNA and RNA are both polymers of which monomer?

Amino Acids

Saccharides

Nucleotides

7 / 20

Explain how non-competitive inhibitors reduce rate.

The binding elsewhere, causes a change in the primary structure, so alters the shape of the active site.

The binding to the active site prevents enzyme-substrate complexes from forming.

The binding elsewhere, causes a change in the tertiary structure, so alters the shape of the active site.

8 / 20

Where do non-competitive inhibitors bind?

The Active Site.

Somewhere on the protein other than the active site.

9 / 20

How do competitive inhibitors bring about a decrease in rate?

By changing the shape of the active site.

By changing the charge on the active site.

By binding to, therefore blocking the active site.

10 / 20

Which points on the above graph show when the enzyme is denatured?

pH4.5

pH 10.5

pH4.5 & pH10.5

11 / 20

Which letter on the above graph shows when the most enzyme-substrate complexes will be formed?

12 / 20

In this reaction, what is the activation energy for the enzyme catalysed reaction?

300kJ mol^-1

50kJ mol^-1

250kJ mol^-1

13 / 20

Which letter represents the enzyme-substrate complex in this diagram?

14 / 20

What is the function of the active site?

a) To hold the substrate in such a way as to strain the bonds so they are easier to break. or
b) To hold the substrate in such a way, as to allow new bonds to form.

a) only

b) only

a) and b)

15 / 20

What is the area of an enzyme called where the substrate binds?

Binding Site

Receptor

Active site

16 / 20

True or False : Endothermic enzyme controlled reactions do not require activation energy?

TRUE

FALSE

17 / 20

Which of these two molecules is a saturated fatty acid?

Neither

18 / 20

What subunits make up a single triglyceride?

4 subunits: 1 glycerol and 3 fatty acids

3 subunits : 1 glycerol and 2 fatty acids

3 subunits : 1 glycerol, 1 fatty acid and 1 phosphate

19 / 20

Molecule D is NOT alpha glucose. What is wrong with it ?

The OH group is in the wrong place on carbon 1

The OH group is in the wrong place on carbon 2

The OH group is in the wrong place on carbon 4

20 / 20

What type of sugar is fructose?

Pentose

Hexose

Heptose

Your score is

Cells Random Retrieval

This quiz contains all the questions in the Cells section. The website will pick 20 questions at random.

1 / 20

What is it called when the two variable regions of an antibody form a complex with two pathogens?

Type your answer.

2 / 20

Which of the following is a similarity between diffusion an osmosis?

Both are passive processes.

Both do not use energy.

Both use energy.

3 / 20

Complete this sentence: Osmosis is the diffusion of water across a partially ________ membrane . Type your answer:

4 / 20

Is a higher water potential...

More free water molecules than another solution.

Fewer free water molecules than another solution.

5 / 20

What type of transport is osmosis?

Active Transport

Diffusion

Something else.

6 / 20

In the above diagram, there are three membrane proteins: A, B and C. Which represents where co-transport occurs?

7 / 20

True or false : Active transport can go down a concentration gradient, or up a concentration gradient.

TRUE

FALSE

8 / 20

Which of the following factors when increased, will increase the rate of diffusion?

a) The Concentration Gradient

b) The Surface Area

c) The Diffusion Pathway

a & c

a & b

a, b & c

9 / 20

Name molecule I.

Ethanol

Glycerol

Cholesterol

10 / 20

At the end of telophase, the cytoplasm cleaves. What is this process called? ( spell it correctly)

11 / 20

Put these letters in the correct order

D, C, A, B, E

D, C, E, B, A

D, C, B, E, A

12 / 20

What term is given to describe G1 phase, S phase and G2 phase combined? ( Spell it correctly)

13 / 20

Why must the solution used to homogenise be cold?

To prevent the centrifuge over- heating.

To reduce the liquidity of the plasma membrane.

To reduce the activity of enzymes.

14 / 20

Which of the following organelles are visible with a light microscope?

a) Nucleus
b) Lysosomes
c) Chloroplasts

A & B

A & C

A, B & C

15 / 20

Assume the scale bar in this image is 2cm long, what is the magnification of this image?

X 40,000

X 400,000

X 250,000

16 / 20

True or false : plasmids contain non essential genes

TRUE

FALSE

17 / 20

Bacterial cell division creates.

4 identical daughter cells.

4 non-identical daughter cells.

2 identical daughter cells.

18 / 20

Name part C

Stroma

Grana

Lamella

19 / 20

Name this organelle.

Rough Endoplasmic Reticulum

Smooth Endoplasmic Reticulum

Golgi Body

20 / 20

Which out of the following cell types are eukaryotic?

A = Animal, B=Bacterial, P=Plants, F=Fungi

A only

A & P only

A,P and F only

Your score is

Exchanges of Substances with the Environment Random Retrieval

This quiz contains all the questions in the Exchanges of Substances with the Environment section. The website will pick 20 questions at random.

1 / 20

What happens to the solutes at the sink?

They are pumped back up phloem going the other way.

They are more dense so sink down, and gather in cells on the lower surface.

Enzymes break them down or join them together as insoluble storage.

2 / 20

Which of the following is an example of a 'source' ?

A photosynthesising leaf.

A Respiring meristem.

A storage tuber in the root.

3 / 20

What piece of equipment is used to measure transpiration ?

Transpirometer

Potometer

Respirometer

4 / 20

What happens to the heart during Diastole?

Atrial and Ventricular walls are relaxed, the Atrioventricular valve is closed.

Atrial and Ventricular walls are relaxed, and the Atrioventricular valve is open.

Atrial wall is relaxed, but the ventricular wall is contracted. The Atrioventricular valve is open.

5 / 20

Why can we not state using this data, CVD is caused by smoking?

Because P only = 0.006 for the linear trend.

Because the 95% Confidence Intervals overlap for two of the results.

Because CVD may have been caused by other things such as diet, exercise , age etc.

6 / 20

Capillaries are made only out of one layer of cells called endothelium. Why is this?

To increase the surface area.

To reduce the diffusion pathway.

To decrease surface area.

7 / 20

As blood moves away from the heart, it travels in which type of blood vessel?

Artery

Vein

Aterioles

8 / 20

What do we call the arteries which supply the heart muscle?

Myocardial Arteries

Coronary Arteries

Cardiac Arteries

9 / 20

In which direction ( if any), would a curve be for diving seal haemoglobin?

Same as human adult

10 / 20

What unit do we use to measure the concentration of oxygen in the tissue?

Moles

Kilo Pascals

Percentage

11 / 20

What term describes the haem groups which contain iron?

Co-factor

Prosthetic Group

Active Site

12 / 20

Why is haemoglobin described as being 'Quaternary'?

Because it contains 4 polypeptide chains.

Because it contains 4 haem groups.

Because it contains more than 1 polypeptide chain.

13 / 20

Haemoglobin is a quaternary protein, how many polypeptide chains make up a single molecule of haemoglobin?

14 / 20

Which letter represents the part that can control water loss?

15 / 20

What effect does emphysema have on the alveoli?

Increased surface area.

Increased mucus secretion.

Reduced surface area.

Constricted bronchi and bronchioles.

16 / 20

Tuberculosis (TB) is caused by bacteria infecting the lungs, where amongst other effects it reduces tidal volume. What happens to the ventilation rate of sufferers?

Increases

Decreases

Stays the same

17 / 20

Which muscles are contracted when you inhale?

Internal Intercostal Muscles and Diaphragm.

External Intercostal Muscles only.

External Intercostal Muscles and Diaphragm.

Diaphragm only.

18 / 20

What shape is the diaphragm when it is contracted?

Domed Up

Domed Down

Zigzag

Flat

19 / 20

How have multicellular organisms adapted to not being able to absorb everything via diffusion over their surface?

A Transport System

Exchange Systems

Transport and Exchange Systems

Moving to maintain a concentration gradient.

20 / 20

If we assume a spongy mesophyll cell is approximately a sphere. Using the formula 4 pi r ² , what is its surface area if its diameter is 80 µm?

80,425 µm ²

20,106 µm ²

5,027 µm²

10,054 µm²

Your score is

Genetic Variation & Information Random Retrieval

This quiz contains all the questions in the Genetic Variation & Information section. The website will pick 20 questions at random.

1 / 20

True or false : The most effective antibiotic for E Coli O121 will also be the most effective antibiotic for EColi K1.

TRUE

FALSE

2 / 20

What caused the antibiotic resistance in the first place?

Independent Assortment

Speciation

Mutation

3 / 20

Stray dogs in the Moscow Subway have learnt to beg for food, and are able to identify humans most likely to feed them. What type of adaptation is this ?

Physiological

Anatomical

Behavioural

4 / 20

Tristan De Cunha is an island populated by a small number of Britons in the early 1800's. What is this an example of ?

Speciation

Genetic Bottleneck.

Founder Effect

5 / 20

True or false : The Founder Effect is a type of genetic drift?

TRUE

FALSE

6 / 20

Which of the following gene mutations will have the least dramatic effect on the polypeptide produced?

Addition

Substitution

Deletion

7 / 20

What is a gene mutation?

The addition of a marker molecule onto the DNA

A chemical which binds to DNA

A change in the DNA base sequence

8 / 20

A sheep cheek cell which is not dividing has 54 chromosomes, how many chromatids will be present during Meiotic Prophase 1 in the testes?

108

9 / 20

What is the main cause of variation between siblings?

Recombination

Mutation

Independent Segregation

10 / 20

Is Anaphase 2 more similar to Anaphase 1, or Anaphase in mitosis?

More similar to Anaphase 1.

More similar to anaphase in mitosis.

11 / 20

How does metaphase 1, differ from metaphase 2 in meiosis?

The centrioles do not produce a spindle.

The homologous chromosomes are lined up in pairs, not single chromosomes.

The nuclear membrane does not breakdown,

12 / 20

On this diagram, what does D represent?

Locus

Homologous Chromosomes

Centromeres

13 / 20

What type of bond forms between the amino acids?

Glycosidic

Phospho-diester

Peptide

14 / 20

What does the 'm' stand for in mRNA?

Migrating

Multiple

Messenger

15 / 20

The genetic code on RNA is read in a set of three bases called a...

Triplets

Codons

Anticodons

16 / 20

What word describes the fact there is more than one set of three bases for each amino acid?

Polypeptide

Polygenic

Degenerate

17 / 20

True or False : The sex chromosomes ( X and Y) are not an homologous pair?

TRUE

FALSE

18 / 20

What do we call a section of DNA which does not carry a code for a functional RNA or amino acid?

Introns

Exons

Variable Number Tandem Repeats

Promoter Sequences

19 / 20

Which type of DNA is not circular?

Mitochondrial

Plant Nuclear

Chloroplast

Bacterial

20 / 20

Eukaryotic DNA is stored, wrapped around which type of protein?

Centriole

Chromosome

Centrosome

Histone

Your score is

Year 13

Biology Year 13 Random Retrieval

This quiz contains all the questions in the year 13 biology section. The website will pick 20 questions at random.

1 / 20

Which bond to restriction endonucleases ( restriction enzymes) break?

Hydrogen

Glycosidic

Phosphodiester

Peptide

2 / 20

Which level of protein structure will the binding of oestrogen alter?

Primary

Secondary

Tertiary

Quaternary

3 / 20

The mRNA travels to the ribosome, where it feeds between the two subunits, exposing the template bases. tRNA molecules each carry a specific amino acid at the top, with a complementary sequence of three bases called an _____7_____ at the bottom. The tRNA anticodons then complementary base pair with the mRNA ____8____.

Once the entire mRNA sequence has been ____11____, it can either pass into another ribosome to make another polypeptide or be degraded.

Base

Codon

Anti-codon

Amino acid

4 / 20

TTA = Leu TTG = Leu TTC = Phe TCA = Ser TAA = Stop What would be the order of amino acids in a polypeptide coded from this sequence?

TTCTTGTTATCATAA

Phe - leu - Leu - Ser - Ser

Phe - Ser - Leu - Leu - STOP

Phe - Leu- Leu - Ser - STOP

5 / 20

What is the native climax community in the UK?

Deciduous trees

Non-deciduous trees

Conifer forest

6 / 20

All the alleles of every gene in a breeding population' is the definition for what?

Gene Pool

Allele Frequency

Allele Variants

Gene Frequency

7 / 20

Which chromosome carries the sex linked alleles?

8 / 20

56.25%

12.5%

6.25%

18.75%

9 / 20

True or False: A stronger stimulus will generate more frequent action potentials.

TRUE

FALSE

10 / 20

What ion is moving during process '3' on the above diagram?

Sodium Ions

Potassium Ions

Phosphate Ions

11 / 20

Honey bees can detect the polarised light from the sun and use it to navigate even in cloudy weather. Is this taxis or kinesis?

Taxis

Kinesis

12 / 20

True or false : Kinesis is a random movement

TRUE

FALSE

13 / 20

What does Darwin's experiment where he placed a black cover over the tip show?

That directional light on the tip effects the direction of growth.

That directional light does not effect direction of growth.

That aluminium foil is toxic to shoot tips.

14 / 20

The above diagram shows the Phosphorus cycle. Name type of organism which carries out process A?

Nitrosomonas

Mycorrhizae

Saprobiont

15 / 20

Denitrifying bacteria use nitrates in the soil to carry out respiration and produce nitrogen gas. Are the vast majority aerobic or anaerobic?

Aerobic

Anaerobic

16 / 20

Anaerobic respiration allows the regeneration of NAD+ in all organisms, which allows glycolysis to continue. How many ATP's are gained during anaerobic respiration of one glucose molecule?

17 / 20

The diagram above represents anaerobic respiration in which type of organism?

Plants

Some Bacteria

Animals

18 / 20

Which chemical does 'F' represent?

NAD

NADP

NADPH

19 / 20

Why can it be advantageous to a plant for more of process 'G' to occur?

More ATP is synthesised

More reduced NADP is synthesised

More Glucose is synthesised

20 / 20

Name structure B

Your score is

The Transfer of Energy Random Retrieval

This quiz contains all the questions in the The Transfer of Energy section. The website will pick 20 questions at random.

1 / 20

The above diagram shows the phosphorus cycle. Name process B

Decomposition

Sedimentation

Weathering

2 / 20

Which process can occur due to the actions of Nitrobacter bacteria?

3 / 20

Suggest the most appropriate units for primary productivity.

KJ m^-2yr^-1

Kg m^-2

KJ m^-2yr¹

4 / 20

The diagram represents anaerobic respiration, name substance 'Z'.

Lactic Acid

Pyruvic Acid

Ethanol

5 / 20

In the absence of oxygen as the final electron acceptor, some processes of aerobic respiration cannot occur. Some of the processes however can continue, which is the last stage that can still function?

Glycolysis

Link reaction

Krebs Cycle

6 / 20

If oxygen isn't available, which substance cannot be regenerated in high enough amounts to keep the system running?

NAD+

Reduced NAD

FAD

7 / 20

Is the column for the ETC reaction in the above diagram correct?

Yes

8 / 20

Is the column for Krebs in the above diagram correct?

Yes

9 / 20

Once 'W' reaches protein complex VI, what does it combine with to form water?

H⁺ + 1/2 O₂

2H⁺ + O₂

2H⁺ + 1/2 O₂

10 / 20

Molecule B enters the Krebs cycle from the link reaction, what is it ?

Triose Phosphate

Pyruvate

Acetyl Co A

11 / 20

How many reduced NADs have been produced from one glucose molecule by the end of the link reaction?

12 / 20

Why did the student set up tube 1?

To allow for comparison

To act as a control

To show light does not effect DCPIP

13 / 20

In the above experiment, chloroplasts were isolated from plants grown at different light intensities. The mutant plants produced more chlorophyll b . The scientists predicted the mutant plants would grow better in any light intensity; why might this be?

Faster production of ATP and reduced NADP.

Less RuBP recycled.

Faster production of ATP and NADP+

14 / 20

In the above experiment, chloroplasts were isolated from plants grown at different light intensities. In each trial scientists collected oxygen for 15 minutes. Calculate the difference in oxygen produced from mutant plants at low and high light intensities at a light intensity of 500 μmol photons m^–2s^–1. Measured in μmol O2 mg^–1 hour^–.

140μmol O2 mg^–1 hour^–

35μmol O2 mg^–1 hour^–

2.33μmol O2 mg^–1 hour^–

15 / 20

Which wavelengths would the rate of photosynthesis be highest in the above experiment?

450nm (blue)

540nm (green)

590nm (orange)

16 / 20

How many turns of the Calvin Cycle are required to balance the number of carbon atoms to produce one glucose molecule?

17 / 20

How many atoms of carbon in ONE molecule of substance C?

18 / 20

What does molecule 'H' represent?

NADP Synthase

cAMP Synthase

ATP Synthase

19 / 20

Where does the energy needed for the splitting of water originate?

ATP

heat

light

20 / 20

Which letter represents a lamella?

Your score is

Responding to Change Random Retrieval

This quiz contains all the questions in the Responding to Change section. The website will pick 20 questions at random.

1 / 20

What is the role of phosphocreatine in muscle contraction?

As a respiratory substrate to feed into glycolysis.

Hydrolysis of ATP

Phosphorylation of ATP

2 / 20

Which protein found in a myofilament has multiple globular heads? (Type your answer carefully).

3 / 20

In the above image, name the unit represented by B.

Sarcomere

Sarcometre

Sarcolemma

4 / 20

The image above shows a muscle fibre. Name organelle A

Microfibril

Myofibril

Sarcofibril

5 / 20

When light falls on cells 1 and 2, only one spot of light is seen. But, when light falls on cells 2 and 3, two spots of light are seen. Say why?

1 & 2 share a neurone, and 2 and 3 share a neurone.

1 & 2 share a neurone, and 2 and 3 have separate neurones.

2 and 3 are both cone cells.

6 / 20

Layer B is the layer which contains the photoreceptor cells. What is it's name ? ( Type your answer).

7 / 20

In order for an action potential to be generated in a Pacinian corpuscle, what must happen?

Enough sodium ions must diffuse out to reach threshold.

Enough sodium ions must diffuse in to reach threshold.

Enough potassium ions must diffuse in to reach threshold.

8 / 20

What type of sodium channels are opened when a Pacinian corpuscle is stimulated?

Voltage-gated Sodium Channels

Ligand-Gated Sodium Channels

Stretch-mediated Sodium Channels

9 / 20

What effect do inhibitory synapses have on the post-synaptic membrane?

Depolarise

Repolarise

Hyperpolarise

10 / 20

Using the diagram, name B

Synaptic Vesicle

Neurotransmitter vesicle

Myelin vesicle

11 / 20

Using the diagram, name D

Ligand Gated Ion Channel

Voltage Gated Ion Channel

Sodium-Potassium Pump

12 / 20

Why can't a second action potential pass immediately after the first ?

During this period the Sodium-potassium pump is not operational.

During this period the voltage gated sodium channels are locked shut.

During this period the potentil difference across the plasma membrane remains positive.

13 / 20

Which direction are the ions moving during process 3 on the above diagram?

Into the cytoplasm

Out of the cytoplasm

14 / 20

What do we call the process happening at '3' on the above diagram?

Depolarisation

Polarisation

Repolarisation

15 / 20

Name protein A in the above diagram.

Sodium Ion Channel

Potassium Ion Channel

Sodium-potassium pump

16 / 20

In a resting neurone, why do potassium ions move out via ion channels?

Due to the greater concentration on potassium ions on the inside compared to the outside.

Due to the electrochemical gradient.

Due to the lower concentration on potassium ions on the inside compared to the outside.

17 / 20

When an neurone axon is at rest, what charge is the extra cellular fluid compared to the cytoplasm?

a) Simple Diffusion
b) Facilitated Diffusion
c) Active Transport

Positive

Negative

Neutral

18 / 20

True or False : Taxis is only ever away from a stimulus

TRUE

FALSE

19 / 20

What is a growth response to light called?

Flurotropism

Gravitropism

Phototropism

20 / 20

Plant responses to stimuli are controlled by what?

Photosynthesis

Growth Factors

Action Potentials

Your score is

Populations, Evolutions & Genetics Random Retrieval

This quiz contains all the questions in the Populations, Evolutions & Genetics section. The website will pick 20 questions at random.

1 / 20

Which of the following is an example of secondary succession?

Volcanic Erruption and lava flow creates new rock.

Earthquake , causes a rock slide down a mountain.

Burning rain forest to clear scrub exposes soil.

2 / 20

Between stages B and C, what will happen to soil depth?

Increase

Decrease

3 / 20

What is lichen made out of ?

Single celled plants.

Fungus.

Fungus and Algae.

4 / 20

Which method would you use to see if there is a correlation between profile height and percentage cover of marsh grass?

Random sampling

An interrupted belt transect

Mark Release Recapture

5 / 20

Which of the following is not an assumption that affects the accuracy of the Mark Release Recapture population estimate?

The marked sample has mixed randomly with the entire population.

The method of marking does not affect the chance of survival

There are no births or deaths.

There is migration.

6 / 20

Why is random sampling used?

It is easier.

To make sure all organisms are counted.

To remove bias.

To make it repeatable.

7 / 20

What should you use to estimate a population of a sessile organism?

A Net

A Pitfall Trap

A meter ruler

A Quadrat

8 / 20

Population growth can be exponential . How would we turn a curved population curve into a straight line graph?

By pressing 'log ₁₀'

By pressing 'Inverse log ₁₀'

By using n ^x

By using x ¹⁰

9 / 20

Is predation a biotic or abiotic factor that effects population size?

Biotic

Abiotic

10 / 20

Was the cold winter an example of an abiotic factor or a biotic one?

Abiotic factor

Biotic Factor

11 / 20

A mild winter and a warm spring meant that the population of robins (birds which feed on insects) increased. This was due to the above average biomass of insects, so more young robins survived. However the following winter was very cold so fewer insects were available in the spring, and the robin population decreased. Is the decrease in robin population, intraspecific competition or interspecific competition?

Intraspecific

Interspecific

12 / 20

What type of variation is show in the graph?

Directional

Disruptive

Stabilising

13 / 20

Which type of selection is when the number of individuals with a particular characteristic, increase around a middle or mid value, and outliers decrease?

Directional Selection

Disruptive Selection

Stabilising Selection

Purifying Selection

14 / 20

Tay Sachs is a recessive disease which leads to the build up of certain lipids which eventually become toxic. The Cajun community in the USA has an incidence of about 1 in every 3,500 births. What is the number of sufferers of Tay Sachs in a Cajun population of 100,000 people?

15 / 20

An Ethiopian breed of cattle has low whey protein in its milk. This is controlled by a dominant allele (M). If 6 % of the herd have low whey protein, what proportion are heterozygotes?

0.94

0.03

0.11

0.06

16 / 20

In this image the ratio of white : yellow : green is 12:4:0

In this image the ratio of white : yellow : green is 1:4:12

In this image the ratio of white : yellow : green is 1:3:12

In this image the ratio of white : yellow : green is 12:3:1

17 / 20

If two genes are on the same chromosome, how do we say they are linked?

Sex Linked

Chromosomally Linked

Allelic Linkage

Autosomally Linked

18 / 20

Which Chromosome contains more genes?

19 / 20

Marfan Syndrome ( TGF Beta) is dominant (T) to the healthy recessive allele(t) . Having a V shaped hairline (V) is dominant to having a straight hairline (v). What proportion of the offspring of a heterozygous father (TtVv) and a heterozygous mother (TtVv) will be health and have a V shaped hair-line ?

3:16

3/16

9/16

9:16

20 / 20

What is the best definition of a 'recessive allele'?

It is the weaker allele which sometimes shows the trait.

It is the weaker allele which never shows the trait.

Two alleles are needed to show the trait.

Only one allele is needed to show the trait.

Your score is

Control of Expression Random Retrieval

This quiz contains all the questions in the Control of Expression section. The website will pick 20 questions at random.

1 / 20

Using bacteria is an example of what type of DNA Amplification?

In Vivo

In Vitro

PCR

Hybridisation

2 / 20

If we cut out a human gene using restriction enzymes and ligate it into a plasmid using ligase, then that plasmid is now 'Recombinant'. What do we call the process of putting the recombinant plasmid into bacteria?

Transcription

Translation

Transition

Transformation

3 / 20

What causes epigenetic markers to be added or removed from DNA?

Exposure to carcinogens.

Inherited mutations from parents.

Exposure to environmental conditions such as a balanced diet.

Exposure to ionising radiation.

4 / 20

Which area of DNA is particularly affected by methylation?

Intron

Exon

Promoter Sequence

Termination Sequence

5 / 20

What is 'Epigenetics'?

The study of the genetic factors that effect Epileptic seizures.

The effect of epinephrine on DNA.

An environmental factor that causes a change to the base sequence of a gene.

An environmental factor that causes 'marker' molecules to be added on to the DNA.

6 / 20

What substances can be used to take mature, differentiated adult cells, and de-differentiate them back into pluripotent stem cells ?(usually only found in embryos).

Hormones

Enzymes

Transcription factors

cAMP second messenger model.

7 / 20

In humans, the zygote ( fertilised egg ) divides into a ball of cells called a Morula. What word describes the cells contained in a morula?

Totipotent

Pluipotent

Multipotent

Unipotent

8 / 20

Which level of protein structure will the binding of oestrogen alter?

Primary

Secondary

Tertiary

Quaternary

9 / 20

What is the oestrogen receptor called when the oestrogen has bound?

Oestrogen Oestrogen Receptor

Oestrogen Bound Receptor

Oestrogen Substrate Bound Receptor

Oestrogen Activator

10 / 20

Where is the oestrogen receptor located?

Nucleus

Cytoplasm

Endoplasmic Reticulum

Golgi Body

11 / 20

What type of hormone is oestrogen?

Amine

Steroid

Eicosanoid

Peptide

12 / 20

Where are transcription factors often stored?

Nucleus

Cytoplasm

Endoplasmic Reticulum

Golgi Body

13 / 20

What is the difference between mRNA and pre-mRNA?

Amino acids joined by peptide bond

Nucleotides joined by a phosphodiester bond

Exons removed

Introns removed

14 / 20

Which enzyme is used during transcription?

DNA polymerase

Helicase

RNA polymerase

Ligase

15 / 20

Cancer is often caused by a mutation causing a cell to divide uncontrollably and spread into other tissues. Name the gene that normally slows or reduces cell division:

Tumour Suppressor Gene

Proto-oncogene

Mitosis Initiation Gene

Mitosis Suppressor Gene

16 / 20

Nitrous acid would therefore cause a __14___ mutation. Ethidium Bromide is used to stain DNA during gel electrophoresis. It can insert between bases, acting in a similar way to an addition mutation and therefore causing a __15___ along the rest of the gene. UV radiation is also a mutagenic agent.

It can cause bonds to form between pyrimidine bases ( thymine and cytosine). This bonding causes polymerases to misread or stop working all together at that point.

Translocation

Addition

Frameshift

Inversion

17 / 20

What word describes when a mutation causes all the following triplet codes to be misread in a different frame?

Non-disjunction

Frameshift

Reading Shift

Triplet Misread.

18 / 20

TTA = Leu TTG = Leu TTC = Phe TCA = Ser TAA = Stop Here is the original sequence : TTCTTGTTATCATAA. Here is a mutated sequence: TTCTTGTTATAACATAA.

What will be the effect on the mutated polypeptide?

Shorter

Longer

1 wrong amino acid, but rest in the same order.

1 wrong amino acid, and the rest also wrong amino acids.

19 / 20

What does the term 'Degenerate' mean when referring to the genetic code?

There is more than one amino acids for each triplet code.

There is more than one triplet code for each amino acid.

DNA degenerates over time.

RNA is unstable and degenerates over time.

20 / 20

Which of the following is NOT a difference between RNA and DNA?

Single stranded/Double stranded

Not made out of nucleotides/ made out of nucleotides

Uracil/Thymine

No Introns/Introns

Your score is

Genetic Variation & Information Random Retrieval

This quiz contains all the questions in the Genetic Variation & Information section. The website will pick 20 questions at random.

1 / 20

What type of selection is shown on the graph?

Length of a giraffe's neck.

Thickness of blubber in a weddel seal.

Human Birth Weight.

2 / 20

Babiana Ringens is a South African plant, which flowers on the ground. They are pollinated by birds, so to attract them they have evolved a sturdy stalk with no leaves or flowers which acts as a bird perch.

Physiological

Anatomical

Behavioural

3 / 20

A mutation in a population of bed bugs in New York City caused the bedbugs to have a thicker, waxier exoskeleton. Why will the allele for thicker , waxier exoskeleton in bed bugs increase in the population?

The thicker exoskeleton makes it easier to lay eggs. More eggs are laid, so more bed bugs with thicker exoskeleton.

The thicker exoskeleton means that the insecticide used to kill them is no longer effective. The thicker exoskeletal bed bugs are more likely to reproduce and pass on the new allele.

The waxy exoskeleton is waterproof, so they are less likely to drown.

4 / 20

How do new alleles occur in a population?

Crossing Over

Independent Assortment

Mutation

5 / 20

Why do the modern day population of Tristan De Cunha has a much higher than average incidence of the genetic disorder Retinitis Pigmentosa?

Retinitis Pigmentosa has less effect on eye sight in the bright sunshine.

Everyone without Retinitis Pigmentosa left the island.

One of the original population carried the allele, and all descendants are therefore more likely to carry the rare allele.

6 / 20

Tristan De Cunha is an island populated by a small number of Britons in the early 1800's. What is this an example of ?

Speciation

Genetic Bottleneck.

Founder Effect

7 / 20

True or false - The Founder Effect is a type of genetic bottle neck?

TRUE

FALSE

8 / 20

Some gene mutations will have no effect at all on the polypeptide, why not?

The genetic code is universal

The genetic code is degenerate

DNA is double stranded

9 / 20

What is a gene mutation?

The addition of a marker molecule onto the DNA

A chemical which binds to DNA

A change in the DNA base sequence

10 / 20

What is the main cause of variation between siblings?

Recombination

Mutation

Independent Segregation

11 / 20

During recombination ( crossing over), genetic material can be swapped between which two structures?

Homologous Chromosomes

Sister Chromosomes

12 / 20

Which number represents prophase 1 of meiosis?

13 / 20

What type of bond forms between the amino acids?

Glycosidic

Phospho-diester

Peptide

14 / 20

How many tRNA molecules can fit into a ribosome at any time?

15 / 20

Which enzyme is used in transcription?

RNA Polymerase

DNA Polymerase

Helicase

16 / 20

What is a difference between RNA and DNA?

DNA is made of of nucleotides, RNA is made out of amino acids.

DNA uses the genetic code, RNA uses sequences of amino acids.

DNA is double stranded, RNA is single stranded.

17 / 20

What is an allele?

A similar gene

A different gene

A different form of the same gene

A cluster of genes

18 / 20

Which word does NOT describe the genetic code?

Degenerate

Universal

Non-Overlapping

Interrupted

19 / 20

Which of the following is not coded for by a gene?

Polysaccharide

Ribosomal RNA

tRNA

Polypeptide

20 / 20

How would you describe the shape of prokaryotic chromosome, when compared to a eukaryotic chromosome?

Circular

Linear

Double Stranded

Double helix

Your score is

Exchanges of Substances with the Environment Random Retrieval

This quiz contains all the questions in the Exchanges of Substances with the Environment section. The website will pick 20 questions at random.

1 / 20

What is translocation the movement of?

Water, with mineral ions.

Pure sucrose.

Organic substances dissolved in water.

2 / 20

How do you calculate the rate of water transpired by the plant?

Measure the drop in water from the beaker then divide by time.

Measure the drop in water from the reservoir above the tap.

Measure the radius of the capillary tube, then using the cross section area, multiply by the distance moved by the bubble and divide by time.

3 / 20

What is the tap and water reservoir above it for?

Getting the bubble into the tube

Measuring the volume of water

Resetting the bubble to the start position

4 / 20

Xylem or Phloem ? - No end plates on these cells

Xylem

Phloem

5 / 20

Which of the following is a way a high salt content in your diet increases your risk of developing CVD?

Salt reduces the water potential of the blood, so water moves out of the endothelium cells via osmosis, causing them to shrivel.

Salt reduces the water potential of the blood, causing water to move in from surrounding tissues via osmosis, leading to an increase in blood pressure, and development of an atheroma.

Salt reduces the water potential of your blood, causing the red blood cells to crenate and form blood clots.

6 / 20

Why can we not state using this data, CVD is caused by smoking?

Because P only = 0.006 for the linear trend.

Because the 95% Confidence Intervals overlap for two of the results.

Because CVD may have been caused by other things such as diet, exercise , age etc.

7 / 20

Does this chart show a causal relationship between Risk of CVD and smoking?

Yes

8 / 20

Which type of blood vessel has the thickest muscular layer?

Vein

Arterioles

Artery

9 / 20

What do we call the arteries which supply the heart muscle?

Myocardial Arteries

Coronary Arteries

Cardiac Arteries

10 / 20

Why is it useful that the Bohr Effect reduces the percentage saturation of Haemoglobin with oxygen?

reduction in saturation also causes a reduction in partial pressure, so a concentration gradient is maintained.

The oxygen has unloaded from the haemoglobin, so it can be exhaled via the lungs.

The oxygen has unloaded from the haemoglobin, so it is available for aerobic respiration in the tissues

11 / 20

During the Bohr Effect, what happens to the affinity of haemoglobin for oxygen?

Lowers the affinity

Increases the affinity

It does not affect the affinity

12 / 20

Haemoglobin is a quaternary protein, how many polypeptide chains make up a single molecule of haemoglobin?

13 / 20

Which number represents a layer which is 2 or 3 times thicker in desert plants?

14 / 20

Using the diagram, which part is a gill filament?

15 / 20

Many species of fish have developed a technique to allow a constant flow of oxygenated water over the gills, even when stationary. This is called Buccal Pumping, how does it work?

The tongue lowers, increasing the volume in the mouth so water moves in. The mouth closes, the tongue then moves up, increasing the pressure and forcing the water out over the gill plates.

The tongue lowers, increasing the volume in the mouth so water moves in. The mouth closes, the fish then swallows the water.

The tongue moves down, increasing the volume in the mouth so water moves in through the opercula ( vents) , over the gill plates , and out through the mouth.

16 / 20

The Great White Shark and Black-tipped Reef Shark are two species which must keep swimming to stay alive. Why is this?

To be able to hunt for prey 24 hours a day.

To stop them sinking.

To maintain a flow of oxygenated water over their gills.

17 / 20

Emphysema is caused by what?

Too much exercise

Cancer

CVD

Smoking or long term air- pollution

18 / 20

Other than surface area to volume ratio, which is an example of a physiological adaptation, which allows an animal to live at hotter temperatures?

Small surface area:volume ratio.

Thicker hair.

Thicker layer of blubber or fat.

More water reabsorbed by the kidneys to reduce water loss.

19 / 20

Why can single celled organisms exchange many substances by simple diffusion over the plasma membrane?

Because the organelles are always located next to the plasma membrane.

Because there is always a concentration gradient.

Because the organisms have a small surface area to volume ratio.

Because the substances do not need to diffuse far (=short diffusion pathway).

20 / 20

What is the surface area to volume ratio of a palisade cell with a volume of 120,000 µm ³ and a surface area of 6500 µm²?

8.33 : 1

1 : 18.46

1 : 0.12

0.12 : 1

Your score is

Cells Random Retrieval

This quiz contains all the questions in the Cells section. The website will pick 20 questions at random.

1 / 20

A doctor vaccinated a group of patients against poliomyelitis. He gave each patient two doses of vaccine, 3 months apart. Calculate the percentage increase in the mean concentration of antibodies in blood between samples 2 and 3.

17.5

18.5

0.95

2 / 20

Complete this sentence: Osmosis is the diffusion of water across a partially ________ membrane . Type your answer:

3 / 20

In the above diagram, there are three membrane proteins: A, B and C. Which represents where facilitated diffusion occurs?

4 / 20

a) Uptake in flask G much greater than in flask F , showing use of ATP in flask G

b) Sodium ion concentration in flask G falls to zero, showing uptake against a concentration gradient

a & b

5 / 20

Which of the following factors when increased, will increase the rate of diffusion?

a) The Concentration Gradient

b) The Surface Area

c) The Diffusion Pathway

a & c

a & b

a, b & c

6 / 20

Which part of the phospholipid bilayer prevents sodium ions leaving via simple diffusion?

Hydrophilic Heads

Hydrophobic Tails

Glycocalyx

7 / 20

In this version of required practical 4, 1cm beetroot cores are soaked in different concentrations of ethanol - 0%, 10%, 20%and 30%. Which graph represents the expected results ?

8 / 20

Give an example of a molecule which would pass through F

Oxygen

Glucose

Chloride ions

9 / 20

Which molecules are found in A?

Saturated Fatty Acids

Unsaturated Fatty Acids

Both Saturated and Unsaturated Fatty Acids

10 / 20

Name structure G.

Extrinsic protein

Intrinsic Protein

Cholesterol

11 / 20

Name the part of molecule J, which makes up part B.

Fatty Acid Head

Glycerol Head

Phosphate Head

12 / 20

To calculate the 'Mitotic Index' you need to stain your root tip cells. Which of the following is NOT an appropriate stain to view Chromosomes with?

Eosin

Toluidine Blue

Aceto-Orcein

13 / 20

If you were to investigate mitosis in plant tissue, which part of a plant would you choose to look at?

Pallisade cells in a leaf

Root Tips

Phloem cells in the stem

14 / 20

Assume the scale bar in this image is 2cm long, what is the magnification of this image?

X 40,000

X 400,000

X 250,000

15 / 20

How big is the biggest gap between the christae ( B)? Assuming that the image shows B to be 7mm, and the scale bar to be 2cm?

0.29 μm

29 nm

0.035μm

16 / 20

True or false : plasmids contain non essential genes

TRUE

FALSE

17 / 20

How are the circular chromosomes separated in prokaryotic reproduction?

As the cell grows, the chromosomes are attached to the membrane, and are pulled apart.

Spindle fibres retract, pulling the chromosomes apart.

Histone proteins 'wind' the chromosomes into two separate poles.

18 / 20

What is structure D called?

Nucleus

Plasmid

Nucleosome

19 / 20

True or False : Prokaryotic ribosomes are the same as eukaryotic ribosomes

TRUE

FALSE

20 / 20

What is the function of this organelle?

Processing and packaging Lipids

Synthesising and processing lipids

Folding and processing proteins

Your score is

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