Category: Biology

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

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

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

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

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.

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

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

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?

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

Was the reduction in insects caused by the cold weather an abiotic factor or a biotic factor?

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

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

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

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

Why is random sampling used?

How many samples should you take to get reliable data?

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

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

What is the equation for Mark Release Recapture?

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

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

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?

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?

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 of the following is a cause of variation?

Which of these is a source of variation?

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

What is 'crossing over'?

Which of the following is not a cause of variation?

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?

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

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

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, split into two groups?

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

What type of variation is show in the graph?

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

What type of variation is show in the graph?

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

What type of variation is show in the graph?

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?

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

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

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?

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?

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

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

What is the definition of a species?

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

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

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

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

What is the formula for the Hardy Weinberg equation?

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

What does 'p' represent ?

What represents the total allele frequency in a population?

Drosophila is a type of fruit fly which is used in many genetic experiments. It has two alleles for eye colour : Red ( R) and White (r). If 0.8 of the alleles are red, how many are white?

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?

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

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 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?

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?

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?

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 allele frequency of the normal healthy genes?

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?

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?

Which Chromosome contains more genes?

Which chromosome carries the sex linked alleles?

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

Which type of allele tends to be sex linked?

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

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

Which sex is the carrier of sex lined genes?

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?

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

What is an autosome?

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

How can you tell if two alleles are autosomally linked?

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?

The actual ratio of phenotypes after several matings between the above two hamsters was more similar to 6:1:1:6. How are the alleles linked?

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?

What term describes when a characteristic is controlled by more than one gene, and the expression of one gene will effect the expression of others?

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

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

What is a gene?

What is the definition of 'genotype'?

What is the definition of 'phenotype'?

What is the definition of 'allele'?

What is the definition of 'homozygous'?

What is the definition of 'heterozygous'?

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

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

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

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 ?

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?

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?

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 could you tell if Marfan Syndrome is Dominant by looking at a pedigree ( family tree)?

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 ?

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 is the percentage probability of the offspring of a father = TtVv and a mother = TtVv would have Marfan Syndrome and a straight hair - line ?

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 ?

What does the term 'Codominance' mean?

A codominant allele' is when both alleles are expressed. One breed of chickens can have Black feathers(B) or White feathers(W). What phenotype will a chicken have with the genotype BW ?

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?

The image above shows a muscle fibre. Name organelle A

The image above shows a muscle fibre. Name organelle C

The image above shows a muscle fibre. Name organelle E

The image above shows a muscle fibre. What is the function of organelle E?

In the above image, which type of protein makes up the myofilaments labelled C? type your answer in carefully.

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

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

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

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

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

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

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

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

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

Breaks down ATP on myosin head

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?

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.

What is the role of phosphocreatine in muscle contraction?

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

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

When a stimulus is detected by a receptor, it generates a potential difference across it's plasma membrane. What is the name of this potential difference?

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

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

Name part A on the above diagram.

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

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

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

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

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

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

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

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

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

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.

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?

Using the diagram, name C

Using the diagram, name E

Using the diagram, name D

Using the diagram, name B

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

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

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

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

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

Whether a synapse is excitatory or inhibitory depends on what?

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

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

If the concentration of neurotransmitter secreted is very low, then threshold may not be reached. What term describes the process of increasing neurotransmitter release? either by multiple presynaptic neurones forming a single synapse or increasing the frequency of neurotransmitter release. 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)

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

Dopamine is a neurotransmitter which has a role in numerous processes in the brain including pain relief. The release of dopamine can be stimulated by chemicals called endorphins produced in the brain. Endorphins attach to opioid receptors on presynaptic neurones that release dopamine. Morphine is a drug that has a similar structure to endorphins and can provide pain relief, explain how.

GABA is a neurotransmitter released in some inhibitory synapses in the brain. GABA causes negatively charged chloride ions to enter postsynaptic neurones. Explain how this inhibits postsynaptic neurones

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

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.

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?

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.

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

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

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

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 the the tiny gaps called labelled X on the above diagram? ( Type your answer)

What is the main function of the fatty substance wrapped around peripheral nerve axons?

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:

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

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

Why is the speed of conduction faster on myelinated neurones?

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

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

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

Axons with a wider diameter axon have...

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

Stimulation ( either by a generator potential in a receptor cell or a neurotransmitter binding to a receptor on a postsynaptic membrane) caused which type of channel to open?

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

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

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

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

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

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

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

Name stage 5 on the above diagram ( spell it carefully!)

What has happened at stage 5?

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

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

Put the above events ( A-F) in order for the passage an action potential.

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).

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

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)

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

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

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