Biology Random Retrieval Y13

Which of the following describes the structure of DNA?

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

What does the C stand for in the genetic code?

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

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?

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?

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

Breaks down ATP on myosin head

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

Whether a synapse is excitatory or inhibitory depends on what?

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

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

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

What is passed along the 4 protein complexes - represented by 'W' on the diagram?

Where does the Electron Transfer Chain ( ETC) occur?

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

How many carbons are present in hexose bisphosphate?

How many carbons are present in glucose phosphate?

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

Where in a chloroplast do the Light Independent Reactions ( LIRs) occur? ( watch your spelling!)

The above diagram shows the phosphorus cycle. Name process B

Which of the following is NOT an accurate way of measuring biomass?

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

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

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

Is the column for Krebs in the above diagram correct?

Is the column for glycolysis in the above diagram correct?

What is the final electron acceptor of the ETC?

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

How many carbons are present in hexose bisphosphate?

Why did the student set up tube 1?

If 'X' on graph A represents 'Light Intensity', what effect would increasing carbon dioxide have on the line (represented in green on the diagram)?

Which graph represents the effect of changing the concentration of carbon dioxide on the rate of photosynthesis?

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

Name substance C

Where in a chloroplast do the Light Independent Reactions ( LIRs) occur? ( watch your spelling!)

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

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

What molecule is represented by 'B' on the diagram?

Which letter represents a lamella?

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.

The image above shows a muscle fibre. Name organelle E

The image above shows a muscle fibre. Name organelle A

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?

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

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

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

Whether a synapse is excitatory or inhibitory depends on what?

Why is the speed of conduction faster on myelinated neurones?

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:

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)

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

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

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

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

True or false : Kinesis is a random movement

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?

What effect does low concentrations of IAA have on root tissue?

Which of the following does NOT stop succession?

What is the native climax community in the UK?

Which of the following is an example of secondary succession?

What is humus?

How many samples should you take to get reliable data?

Why is random sampling used?

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

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

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

What type of variation is show in the graph?

What type of variation is show in the graph?

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'?

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 ?

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?

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?

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

What is the definition of 'homozygous'?

What is the definition of 'allele'?

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

What effect will increased acetylation have on a gene?

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

What is 'Epigenetics'?

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

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

What does the 'si' stand for in siRNA?

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

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

Where are transcription factors often stored?

What is the difference between mRNA and pre-mRNA?

Which enzyme is used during transcription?

Which of the following describes the structure of DNA?

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:

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

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

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

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