Category: Biology

PCR allows DNA to replicate by semi-conservative replication. But what word best describes the rate at which it amplifies?

PCR is an example of what type of DNA amplification?

Apart from the desired gene sequence, what else needs to be added to a recombinant plasmid in order for it to be expressed by bacteria?

Which area of DNA is particularly affected by methylation?

Which enzyme will the Oestrogen - Oestrogen Receptor ( OOR) activate?

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

What are the proteins called that also need to bind to activate RNA polymerase?

Which enzyme is used during transcription?

Long term exposure to Oestrogen can increase the risk of developing breast cancer. The exact mechanism is still not fully understood, but which of the following is definitely NOT a suggested mechanism ?

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?

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?

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: TTCTTGTTATAACATAA.

What will be the effect on the mutated polypeptide?

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

What type of mutation has occurred?

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

If a template strand has the code starting at the 5 prime end with 5' GCTAAGCA 3'. What would be the order the bases would be added to the new strand ?

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

What does the A stand for in the genetic code?

What is it called when succession is stopped artificially?

What is the biological meaning of succession?

A student is using a quadrat to estimate percentage cover of clover on the school field. What is the most accurate way to do this?

What is the advantage of carrying out an interrupted belt transect compared to belt transect?

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

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

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. What is the allele frequency ( as a decimal) of the light allele in the population?

The probability of an individual having Cystic Fibrosis is about 1 in 2500 in the UK. How many individuals will suffer with Cystic Fibrosis in a city of 1.2 million people in it's population?

What represents the total allele frequency in a population?

The Hardy Weinberg principle only applies to a population that is or has ____.

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

What is the probability of a colour- blind father and a homozygous dominant female having a colour blind child?

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 ?

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?

How can you tell when an allele is recessive in a pedigree (a family tree)?

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

What is the definition of 'phenotype'?

Breaks down ATP on myosin head

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

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

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

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

Doctors investigated two ways of measuring the effect of general anaesthetics. In one method they timed how long it took to stop blinking, and then repeated the investigation using a machine to record when brain activity showed they were unconscious. Blinking involves cholinergic synapses. Anaesthetic S is a similar shape to acetylcholine. Suggest how anaesthetic S stops the transmission across the synapse.

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?

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

True or False - Axons with a narrower diameter have a faster speed of conduction.

True or False - The speed of conduction along an unmyelinated neurone is around 5 m/s ( jogging pace).

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).

What has happened at stage 5?

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

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

How can charged ions cross a plasma membrane?

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

True or false : Kinesis is a random movement

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

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

Plant responses to stimuli are controlled by what?

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

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

The above table shows the volume and density of a fresh wood sample, then the volume and density of the same sample after it was dried. Calculate the percentage of water in the sample (water weighs 1g / ml)

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

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

What is the final electron acceptor of the ETC?

What is represented by molecule Y?

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

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

Where does the Krebs Cycle occur?

How many pyruvate molecules are made from one glucose molecule in glycolysis?

What is represented by molecule D?

What is represented by molecule C?

How many phosphate groups are present in hexose bisphosphate?

What is the first process to happen in glycolysis?

A buffer was not used in the above experiment, what would happen to the pH during the experiment.

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

Which chemical does 'E' represent?

What does molecule 'H' represent?

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

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?

Which enzyme will the Oestrogen - Oestrogen Receptor ( OOR) activate?

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____.

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.

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?

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?

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

This gene interaction once again alters the phenotype ratio. Which type of Epistatic allele will produce a ratio of 9:3:4?

What is the definition of 'phenotype'?

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

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

How can charged ions cross a plasma membrane?

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

True or false : Kinesis is a random movement

What response do roots have to light?

True or False : Symbiotic fungi generally increase the amount of glucose in a plant.

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)

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

Name molecule Y

Which chemical does 'E' represent?

Which membrane is represented by 'C' on the diagram?

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) ?

Which enzyme do we use to convert mRNA into cDNA?

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

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?

Which of the following carries the code for the order of amino acids?

Name the type of reaction that joins the nucleotides together.

What is humus?

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

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

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

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

What is the definition of 'allele'?

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 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.

What is the stimulus detected by a Pacinian corpuscle? (type your answer)

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

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

This diagram shows part of the nitrogen cycle. Which two processes form nitrification?

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

Why did the student set up tube 1?

Put the following into the correct order:

a) Lower plants die due to lack of photosynthesis.
b)Fish die due to lack of dissolved oxygen.
c) Decomposers respire aerobically to decompose the dead plant matter.
d) Increased algae blocks out the light.
e) Minerals leach into the waterway.
f) Increased minerals cause an algae to grow rapidly.

The concentration of nitrates and phosphates in the soil can be increased by the addition of fertiliser, but what ecological damage can this cause?

What are the strands of fungi called?

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

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

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?

Where does the Electron Transfer Chain ( ETC) occur?

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?

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 concentration of Oxaloacetate produced by cells exposed to IDH1 ?

Molecule Z represents ATP. How is this molecule of ATP generated?

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

Where does the Krebs Cycle occur?

How many carbon atoms are carried into the Krebs cycle in each Acetyl Co A?

Name molecule Z

Where does glycolysis occur?

In the above experiment, chloroplasts were isolated from plants grown at different light intensities. Why did the scientists measure the rate of oxygen produced?

Which substance is represented by I?

Which two products from the Light Dependent Reactions ( LDRs) does the Calvin Cycle use?

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

Which membrane is represented by 'C' on the diagram?

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.

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

Using the diagram, name E

True or False: If too few sodium channels are opened by a stimulus on an neurone membrane, then no action potential is generated.

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

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

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

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

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

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?

In the above experiment on woodlice, how would you make the method more valid?

True or false : Kinesis is a random movement

True or False : Taxis is when an organism either moves faster in harsh conditions or turns less in harsh conditions.

What is the definition of a stimulus?

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

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

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

In root tips growing parallel to the soil, where will the highest concentration of IAA be found ?

What affect does IAA have on shoot tips?

What word describes the growth response of a plant to a stimulus?

Which of the following is an example of primary succession?

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

What is the biological meaning of succession?

Why is random sampling used?

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

Is the following an 'Abiotic adaptation' or a 'Biotic Adaptation': Monarch butterflies fly south when the number of daylight hours shorten?

Which type of selection is human birthweight showing? (As low birth - weight babies and high birth - weight babies are less likely to survive)

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?

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?

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?

What is 'crossing over'?

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 is the allele frequency ( as a decimal) of the light allele in the population?

The Hardy Weinberg principle only applies to a population that is or has ____.

This gene interaction once again alters the phenotype ratio. Which type of Epistatic allele will produce a ratio of 9:3:4?

What is an autosome?

How can you tell from a pedigree (family tree) that a trait is sex linked?

Which chromosome carries the sex linked alleles?

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 ?

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'?

In a PCR reaction, the DNA is heated at the start of the cycle to around 95 degrees C. What is the reason for this?

PCR is an example of what type of DNA amplification?

Apart from the desired gene sequence, what else needs to be added to a recombinant plasmid in order for it to be expressed by bacteria?

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?

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

Can extra methylation be removed from the DNA?

Which type of stem cells are not found in adults?

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

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.

What is the removal of introns called?

If hypermethylation happens to a proto-oncogene, what effect will this have on the rate of mitosis?

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.

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?

Which of the following carries the code for the order of amino acids?

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

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 method by which DNA replicates.

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

What does the A stand for in the genetic code?

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

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

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

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

Does this bar cart show a correlation between number of cigarettes smoked, and the risk of CVD?

Why do the guard cells become 'curved' when they swell up?

Using the diagram, which part is a lamella?

Digested pathogen proteins can be displayed on the cell surface membrane of a phagocyte. What is this called?

Type your answer.

Which type of cell can engulf a pathogen?

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

Give an example of a molecule which would pass through F

What type of molecules are most likely to pass through C?

How long is one complete cell cycle on this graph?

The Christae of the mitochondrion shown in this picture are 2m x 10^-8wide (A). How many 'nm' is this ?

What type of bond forms between water molecules?

In the diagram, what name is given to strand A?

Which enzyme breaks the bonds between complementary base pairs in preparation for DNA replication?

Name the pentose sugar found in DNA.

More than two amino acids joined together is called what?

Which of the following terms best describes the phosphate part of a phospholipid?

What type of bond forms between two monosaccharides?

Which of the following molecules contain a phosphate group?

ATP can be used to add a phosphate group onto molecules. What is this process known as?

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 for many generations in a medium containing N¹⁵. The bacteria were then removed from the N¹⁵ , and placed in medium containing .N^14.. When The DNA from this first generation was centrifuged ( tube A), what pattern did the DNA bands form?

Which molecules bind to the exposed bases when DNA becomes single stranded?

The two strands in DNA are 'antiparallel'. What does antiparallel mean?

What base does the 'T' stand for?

Name the pentose sugar found in DNA.

How do competitive inhibitors bring about a decrease in rate?

Which line shows the rate when substrate is limited ?

Which letter on the above graph is the ' Saturation' point?

When an enzyme is denatured, which bonds are NOT broken?

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

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

What type of reaction could break apart the bonded amino acids?

If this diagram represented the plasma membrane of an epithelial cell in a human small intestine. What solutions would be on side'a' and side 'b'?

Which of the following terms best describes the phosphate part of a phospholipid?

Fats that contain unsaturated fatty acids (compared to saturated) are more likely to have:

It forms strong, straight fibres called what ?

What type of sugar is fructose?

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

Which type of cell activates other immune cells in an immune response?

Name the molecules that generate an immune response when detected by the body. Type your answer.