Category: Biology

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?

Can extra methylation be removed from the DNA?

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

Which type of stem cells are not found in adults?

The morula hollows out into a hollow sphere, with a small group of cells at the bottom called teh inner cell mass which go on to develop into an embryo. What do the outer cells go on to make?

After fertilisation, zygotes ( fertilised eggs) divide by which process?

Which molecule is created during transcription?

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

If hypomethylation ( reduced methylation) happens to a tumour suppressor gene 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.

Which type of mutation will not cause a frameshift?

What type of mutation causes a sequence of bases to be moved from one location to another?

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

Which word does NOT describe the genetic code?

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

What does the C stand for in the genetic code?

What does the A stand for in the genetic code?

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

True or false: Succession only happens on land?

What is it called when succession is stopped artificially?

Which factor will the lichen and mosses change the most?

Which of the following is an example of primary succession?

True or false : Succession is the same as evolution.

Using mark release recapture, what would the population of woodlice be if : 27 were caught in the first sample , and 16 unmarked caught in the second, and 3 were marked?

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

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

Natural selection can change allele frequencies over time, due to those with the best alleles surviving and reproducing. What is the term used to describe the 'chance' or 'random' selection of alleles in a population?

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

Which of the following is a cause 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?

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?

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?

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

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

Being colour blind is a sex-linked disorder. What is the probability of an unaffected male having a colour- blind child with a heterozygous female?

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?

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

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.

Which protein blocks the actin-myosin binding site in a relaxed myofibril?

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?

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

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

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

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

When an action potential is generated, there is a temporary reversal of the polarity of the neurone membrane at that point. Does this mean that:

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.

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

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

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

Which word best describes the charge distribution across a resting axon plasma membrane?

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

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

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

Which of the following is true?

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

Plant responses to stimuli are controlled by what?

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

True or False : Fungi can increase the surface area of roots

This diagram shows part of the Nitrogen cycle. Name process E

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?

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

What would be the most appropriate units for measuring biomass?

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

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

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?

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 Acetyl Co A produced by cells exposed to IDH1?

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

Name molecule Z

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^–.

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

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

Which substance is represented by I?

The transfer of electrons along the carrier proteins causes hydrogen ions to be moved across the membrane, causing a proton concentration gradient. the protons than pass back through the membrane creating ATP. What is the name of this process involving using electrons to produce a concentration gradient?

Name structure E

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?

Can extra methylation be removed from the DNA?

What is the difference between 'totipotent' stem cells and 'Pluripotent' stem cells?

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

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 ?

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

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?

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 short haired and white?

Which of the above diagrams represents either end of an 'A Band' in muscle?

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

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

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

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

What effect does high concentrations of IAA have on shoot tip tissue?

Which of the following molecules require phosphorus? a) Protein b) DNA c) ATP

Many decomposers secrete enzymes to digest organic matter, then absorb the products they require. The digested products which are not required remain in the soil. The digestion of which organic substance will result in the presence of ammonia in the soil?

External digestion involves the secretion of enzymes outside of the organisms outer-most layer. Which term best describes this?

How many carbon atoms are in a molecule of Citrate?

How many carbon atoms are in a single molecule of molecule B?

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

Which area of DNA is particularly affected by methylation?

What type of hormone is oestrogen?

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.

What is the position of gene on a chromosome called?

Which type of DNA is not circular?

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

In hamsters two genes are autosomally linked : Fur and Eye colour . Where Ginger fur = G, and White fur =g. Black eyes = B and red eyes = b. In a cross between a homozygous recessive male for both traits and a heterozygous female for both traits , what would be the expected ratio of Ginger & Black eye, White and Black eye, ginger and red eye and white with red eyes?

What is the definition of 'genotype'?

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

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

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

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

Using the diagram, name C

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.

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

The diagram shows an Arctic food web. The arctic fox consumes a 35% share of the primary consumers, with the Gulls and skuas consuming 65%. The arctic fox achieves a 9% energy efficiency, from the total primary consumers productivity of 6,112kJ m^-2yr^-1. What is the productivity of the arctic fox?

The diagram above shows one form of anaerobic respiration, name molecule 'Y'.

Is the column for glycolysis in the above diagram correct?

The transfer of electrons along the carrier proteins causes hydrogen ions to be moved across the membrane, causing a proton concentration gradient. the protons than pass back through the membrane creating ATP. What is the name of this process involving using electrons to produce a concentration gradient?

What is 'Guano'?

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

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

Which process can occur due to the actions of Nitrobacter 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 does GPP represent in a given area?

What does GPP stand for?

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

What should go in box 'X'?

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

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

Why did the student set up tube 1?

Name the technique detailed in the above diagram ( spell it correctly!)

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?

Name substance D

Which chemical does 'F' represent?

Once light has hit structure D, and the electrons have left the chlorophyll, they can either be passed on to form F or follow path 'G'. What is path 'G'?

What type of molecule is represented by 'C'?

What type of molecule will pick up the 'high energy' electrons in PSII?

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

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

Which of the above diagrams represents the myofilaments a 'Z line' in muscle?

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

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

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

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

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

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

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

On the diagram, F is a voltage gated ion channel on an excitatory synapse, but which type of ion does it allow through?

Using the diagram, name E

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

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

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

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

What has happened at stage 5?

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

Name protein A in the above diagram.

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?

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

Plant responses to stimuli are controlled by what?

Which of the following does NOT stop succession?

What is it called when succession is stopped artificially?

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

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

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?

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

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?

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.

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

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

Speciation is when a new species arises from another: they can no longer produce fertile offspring because their DNA is no longer compatible. What term describes this inability between two populations to reproduce successfully?

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?

What represents the total allele frequency in a population?

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?

What does the term 'Codominance' mean?

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 ?

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

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

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

PCR is an example of what type of DNA amplification?

Sometimes, two marker genes are used: The first marker gene is often an antibiotic resistance gene to show if the plasmid is present; the bacteria can only grow on a plate containing the antibiotic, if they have the antibiotic resistance gene on the plasmid. The second is often a gene with a colour change, which is broken by the insertion of the fragment.

e.g. An example of a gene to test for the presence of a fragment is Green Fluorescent Protein (GFP) glowing or not. What would a bacterial plate look like that contained an antibiotic, and was spread with bacteria which had been transformed with a plasmid and had a new gene fragment in?

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

What bond does DNA ligase create?

What do we call it if the restriction enzyme cuts both strands of DNA in a staggered position to create an overhang?

What is an advantage of using iPS cells to treat degenerative disorders, instead of embryonic stem cells?

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 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 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.

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.

What type of mutation causes a sequence of bases to be moved from one location to another?

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?

What is the position of gene on a chromosome called?

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

Which type of DNA is not circular?

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 ?

Name the type of reaction that joins the nucleotides together.

Which component of a nucleotide contains nitrogen atoms?

Which of the following is the result of a chromosome mutation?

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

On this diagram, what does C represent?

What molecule is made in eukaryotic transcription?

Which bonds are broken by the enzyme used in transcription?

How does an increase in wind speed, increase the rate of transpiration?

Which part is hydrophobic?

Which phase is when the sister chromatids are pulled to opposite poles by the spindle fibres.

Why must the solution used to homogenise be cold?

The image shows palisade cells in a leaf. Line A (width) measures 8mm, and the magnification of the image is x10,000. What is the actual width (A) of the palisade cell?

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

What is the function of this organelle?

Which equation represents the action of ATP Synthase?

Explain why line B forms a plateau:

Why does the graph plateau?

The optimum temperature for this enzyme is actually 40^oC. Describe what the line would look like on the above graph.

Which word best describes the shape of the substrate?

Which monomer is the animal storage polysaccharide made out of ?

What type of bond forms between the monomers in starch?

Which molecule is Beta - Glucose?

What word best describes this molecule?

Name the enzyme involved in the breakdown of ATP

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?

True or False : The enzyme DNA polymerase can only bind to double stranded DNA?

How many bonds form between the Bases C and G when the base pair?

What type of bond forms between complementary base pairs?

Penicillin works by binding to an enzyme called transpeptidase in bacteria, changing the shape of the active site. When penicillin binds, it means the bacteria can no longer make cross-bridges in the bacterial cell wall. What type of inhibitor is penicillin?

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

On the above diagram, which letter represents the activation energy without an enzyme?

What level of protein structure contains alpha helices and beta pleated sheets?

Other than peptide bonds, a folded protein also contains:

i) Hydrogen Bonds
ii) Ionic Bonds
iii) Di-Sulphide Bridges.

Which bonds form the secondary structure?

Water is produced during the bonding of two amino acids. Where do the hydrogen and oxygen molecules originate from?

Which biochemical test is used to identify lipids?

The 'tail' of a fatty acid can be a variable length molecule. But what type of molecule is the tail?

What elements are lipids made out of?

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

Which monomer is this polysaccharide made out of?

This polysaccharide of glucose is branched. What is the advantage to the organism of branching ?

What type of reaction is used to join two monosaccharides?

Which type of cell travels to the site of infection, and secretes a chemical which kills infected cells?

In the above experiment, why would the student be advised to take repeat readings?

In the above experiment, why would the student be advised to take repeat readings?

A worm native to fresh water will die when placed in sea water. Why is this?

In the above diagram of three cells, will water move from :