Category: Biology

Acetylation is the addition of a C2H3O group which contains a double bonded oxygen. Where does acetylation occur?

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

Which area of DNA is particularly affected by methylation?

Cardiomyocytes are an example of what type of stem cell?

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

What effect will siRNA have on expression of a gene?

What does the RISC complex do to the mRNA?

What does the 'si' stand for in siRNA?

What forms the substrate in a Transcription complex formed from OOR and RNA Polymerase?

Where are transcription factors often stored?

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 ____8____.

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.

Which molecule is created during transcription?

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

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?

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.

Which type of DNA is not circular?

Which two molecules does DNA Polymerase join together?

What attracts new 'free' nucleotides to the exposed template strand during DNA replication?

Name the enzyme that breaks the hydrogen bonds between complimentary bases during DNA replication.

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

Which stage represents the climax community?

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

Which stage represents lichen and mosses?

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

What is the word used to describe 'All the different populations in a habitat along with all the abiotic conditions'?

What type of population does genetic drift have the greatest effect on?

What type of speciation is caused by reproductive Isolation, but without a physical barrier between two populations?

What type of variation is show in the graph?

Which type of selection is when the number of individuals with a particular characteristic, increase around an extreme or outlier value?

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

What is 'crossing over'?

In the creation of gametes, which process mixes up the alleles?

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?

What does 'p' represent ?

If B = black, W = white and BW = speckled feathers in hens. Two heterozygous speckled hens mated, what will the ratios be of offspring that are black : speckled : white?

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 ?

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

What is the definition of 'heterozygous'?

What is the definition of 'allele'?

One form of muscle disease is caused by a mutated allele of a gene. This leads to production of myosin molecules that are unable to bind to other myosin molecules. If myosin molecules are unable to bind to other myosin molecules, this prevents muscle contraction. Suggest why.

One role of ATP in muscle contraction is to provide the energy required for the 'powerstroke' of the myosin head. What is the other use of ATP in muscle contraction?

The image above shows a muscle fibre. Name organelle E

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

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

If a neurotransmitter binds to the post synaptic membrane and causes potassium ion channels to open, would it be excitatory or inhibitory?

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

Using the diagram, name D

Why does an increase in temperature ( up to 40 degrees) cause an increase in the speed of conduction along a neurone?

Once an action potential has been generated, what causes the next section of the axon membrane to become depolarised?

In the above diagram, which graph shows the correct effects of increasing a stimulus?

After an action potential has fired, the refractory period acts as the following:

• a) Prevents action potentials overlapping
• b) Limit the frequency of action potentials
• c) Limit the size of action potentials
• d) Makes action potentials travel unidirectionally.

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

The period of time after an action potential, when another action potential cannot pass along that section of a neurone is called the ____________ period ( Watch your spelling).

Which of the events (A - F above) starts depolarisation? Type the letter in the box

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

Flatworms turn more frequently in response to an increase in light intensity. Is this taxis or kinesis?

True or false : Kinesis is a random movement

How does IAA bring about this effect?

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

What are the strands of fungi called?

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

The diagram shows an Arctic food web. Why is the energy efficiency between Forbs and Rock Ptarmigan lower than that between a Rock Ptarmigan and an Arctic Fox?

a) Because more of the body of the Ptarmigan is eaten than the Frobs.

b) Because more of the Ptarmigan is digested and absorbed (assimilated)

c) Because a Ptarmigan is bigger than a Forbs

What would be the most appropriate units for measuring biomass?

The above apparatus was left in a water bath until it reached a constant temperature. It was then left for one hour before starting. Why was it left for one hour before starting?

What term is used to describe the whole process of using energy from electrons in Redox reactions to generate ATP called?

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

A single molecule of W is produced per turn of the Krebs cycle, and it carries hydrogen off to the ETC. What is it?

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

How many times does the Krebs cycle happen per glucose molecule?

Where does the Krebs Cycle occur?

Which graph represents the effect of changing the temperature on the rate of photosynthesis?

How do you calculate the Rf value for a substance?

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

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

If six molecules of molecule C are produced, how many will be regenerated into substance A?

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

What does substance H do to substance B?

What does molecule 'H' represent?

High energy' electrons leave the chlorophyll molecule: What state does that leave the chlorophyll molecule in?

Name the enzyme that breaks the hydrogen bonds between complimentary bases during DNA replication.

What does the C stand for in the genetic code?

What is the biological meaning of succession?

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

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

Natural Selection means that over time the frequency of beneficial alleles in a population will do what?

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 ?

In guinea pigs, Short hair (S) is dominant to long hair (s). In a monohybrid cross between a heterozygous mother, with a heterozygous father, what ratio of long hair to short hair will the offspring have ?

What is a gene?

The image above shows a muscle fibre. Name organelle C

The image above shows a muscle fibre. Name organelle A

Point C is the point where most colour sensitive photoreceptor cells are located. What is it called?

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

What affect does IAA have on shoot tips?

What is the formula for NPP?

What should go in box 'X'?

What is the final electron acceptor of the ETC?

In the above experiment, what measurements should the student take to measure the rate of photosynthesis?

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

In non-cyclic photophosphorylation, the electrons that leave the chlorophyll are replaced by the splitting of water. What is the name of this process?

Primers are short single stranded pieces of complementary sequenced DNA. Which ISN'T a reason to add specific primers added to the PCR reaction?

A methyl group has the structure CH3. Methylation is the addition of a methyl group onto what?

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

Which method would you use to see if there is a difference between the percentage cover of moss on the north face compared to the south face of tree trunks?

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?

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

What type of variation is show in the graph?

Which of these is a source of variation?

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 homozygous dominant healthy individuals in a Cajun population of 100,000 people?

The muscle filament in the above diagram is relaxed, what would happen to the following zones when it contracts?

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

What has happened at stage 5?

Which ions are moving across the membrane during process '4'?

What does Boysen and Jensen's experiment using agar show?

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

In the formula for the calculation of NPP, what does the 'R' stand for?

Is this the correct equation for anaerobic respiration in yeast cells? : Glucose → Carbon Dioxide + Water + Ethanol

How many carbons are present in hexose bisphosphate?

Which wavelength of light would the rate of photosynthesis be lowest in the above experiment?

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

The above diagram shows the phosphorus cycle. Name process B

True or False : Fungi can increase the uptake of water by a plant

Which stage of the nitrogen cycle does the above equation represent?

Nitrogen fixation from gas to compound, requires a large amount of energy (at least 16 ATP molecules and 8 electrons). A select few bacteria can carry out this task, but which of the following CANNOT fix nitrogen?

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

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

In a woodland, 8,150 kJ m^-2yr^-1 is lost as heat from respiration. The gross primary productivity of the wood is15,000 kJ m^-2yr^-1. What is the net primary productivity of the woodland?

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?

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

Name molecule 'Z'

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?

How many carbon atoms are in a molecule of Citrate?

Name molecule Y

Why did the student set up tube 1?

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

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

Name substance C

Name substance A

The splitting of water at PSII creates molecules A & B, what do A and B represent?

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

One form of muscle disease is caused by a mutated allele of a gene. This leads to production of myosin molecules that are unable to bind to other myosin molecules. If myosin molecules are unable to bind to other myosin molecules, this prevents muscle contraction. Suggest why.

In the sliding filament theory, what causes the actin-myosin binding site to be exposed?

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

What is the structural adaptation which give cones high visual acuity compared to rod cells?

Point C is the point where most colour sensitive photoreceptor cells are located. What is it called?

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

Put the following statements in order to explain what happens at an excitatory synapse:

• a) Voltage gated calcium channels open.
• b) Synaptic vesicles fuse with the pre-synaptic membrane
• c) If threshold is reached, an action potential is generated
• d) Calcium ions diffuse into the presynaptic neurone.
• e) Arrival of an action potential
• f) Neurotransmitters bind to receptors with associated sodium channels
• g) Neurotransmitters diffuse across the cleft
• h) Sodium ions diffuse into post synaptic membrane

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

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

In the above diagram, which graph shows the correct effects of increasing a stimulus?

In order for an action potential to be triggered, a certain number of sodium channels must open, each setting a change in the potential difference.

What name is given to this change in potential difference that must be reached ? (Type your answer)

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

After a stimulation has occurred, why do ions move out of an axon?

Name protein C in the above diagram.

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

In the above experiment on woodlice, what is the Independent variable?

Maggots follow a scent up a concentration gradient towards a food source. Is this taxis or kinesis?

What would be a suitable control for Went's experiment ?

Which of the following is true?

What response do roots have to light?

Which type of plants are more likely to be the pioneer species in secondary succession?

Which factor will the lichen and mosses change the most?

True or false : Succession is the same as evolution.

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

How many samples should you take to get reliable data?

Why is random sampling used?

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

Which of the following isn't an example of genetic drift?

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?

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

Which type of selection is when the number of individuals with a particular characteristic, split into two groups?

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. How many are heterozygotes?

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?

What represents the total allele frequency in a population?

What is the formula for the Hardy Weinberg equation?

In the actual ratio of 6:1:1:6, there were more of the ginger and black eyed hamsters and more of the white with red eyed hamsters than expected. Therefore, there are proportionately fewer of the mixed traits (Ginger and red eyes and white with black eyes). What process allowed those few mixed trait offspring to occur?

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?

In guinea pigs, Short hair (S) is dominant to long hair (s). In a monohybrid cross between a heterozygous mother, with a heterozygous father, what ratio of long hair to short hair will the offspring have ?

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

What is the definition of 'allele'?

Primers are short single stranded pieces of complementary sequenced DNA. Which ISN'T a reason to add specific primers added to the PCR reaction?

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?

Which bond to restriction endonucleases ( restriction enzymes) break?

What is 'Epigenetics'?

Which molecule does the SIRNA / protein complex (RISC) bind to?

SiRNAs are formed when large double stranded molecules of RNA are cut up into small section which then do what?

The mRNA travels to the ribosome, where it feeds between the two subunits, exposing the template bases. tRNA molecules each carry a specific ______6____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____.

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.

Which molecule is created during transcription?

Which enzyme is used during transcription?

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

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?

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:

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

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

What type of mutation has occurred ?

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

Which word does NOT describe the genetic code?

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

If a section of DNA contains 21% base C, what percentage will base A have?

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?

Name the type of reaction that joins the nucleotides together.

What type of mutation is this ? ACCTGG becomes ACGTGG

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

During Transcription, the two DNA strands are separated. What attracts free floating RNA nucleotides to the exposed bases?

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

What happens during Ventricular Systole?

Which term describes that guard cells when the plant has plenty of water available?

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

During co-transport of glucose in the ileum, active transport is needed to establish a concentration gradient of which substance?

What effect does having more of molecule 'I' have on the membrane?

The diagram shows the cell cycle. What does 'M' stand for in the diagram? ( Spell it correctly)

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

This is found inside most eukaryotic cells, what is A?

If DNA replicated by a Conservative method, what would the DNA bands look like after one generation in N¹⁴ medium(Tube A)?

In this experiment bacteria were grown in a growth medium containing N¹⁵. What isN¹⁵?

Will increasing the concentration of substrate cause an increase in the rate of an enzyme inhibited by a non-competitive inhibitor?

Where do non-competitive inhibitors bind?

Describe what the line would look like when a competitive inhibitor was added to the reaction.

In this reaction, what percentage difference in energy needed for an enzyme catalysed reaction, compared to an uncatalysed one?

What is the standard structure of a phospholipid?

What would the products be from the hydrolysis of sucrose?

Hydrogen ionconcentration is used to calculate pH. Which of the following statements is true?

Which of the following molecules contain a phosphate group?

Which process requires the use of ATP?

In a section of double stranded DNA, there were 62 bases. Of these, 20 were A. How many of the bases were C?

Where do non-competitive inhibitors bind?

Why does the graph plateau?

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

What has happened to the enzyme when it becomes denatured with a high temperature?

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

What is the name of the bond that forms between two amino acids?

Which of the above three molecules shows a correct bond between glycerol and a fatty acid?

Which of the following is not true about triglycerides?

What is the formula for glycerol?

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

It forms strong, straight fibres called what ?

What type of bond forms amylose?

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

What would the products be from the hydrolysis of sucrose?

Which disaccharide is made from glucose and galactose?

Is one of the monomers beta glucose ?

NMO is a disease NMO is a disease that leads to damage to nerve cells in the spinal cord. A person with NMO produces anti-AQP4 antibody that attacks only these nerve cells. Explain why the anti-AQP4 antibody only damages these cells

Name the contents found in C.

During phagocytosis, the pathogen is detected by molecule A on the cell surface membrane. What are the molecules labelled A called?