Biology Random Retrieval Y13

What substances can be used to take mature, differentiated adult cells, and de-differentiate them back into pluripotent stem cells ?(usually only found in embryos).

What are iPS cells?

Which enzyme is used during transcription?

Which of the following describes the structure of DNA?

Which word does NOT describe the genetic code?

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?

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?

The image above shows a muscle fibre. Name organelle C

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.

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

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

What is the definition of a stimulus?

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

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

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

In which stage of respiration is oxygen required?

True or False - Using a different solvent does not alter the distance travelled by different substances in this technique?

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

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

The above diagram shows the phosphorus cycle. Name process B

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

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

What is the formula for NPP?

In this investigation, are the yeast respiring anaerobically or aerobically ?

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 represents anaerobic respiration, name substance 'Y'.

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

Is the column for Krebs in the above diagram correct?

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

What should go in box 'X'?

The ETC develops a proton gradient as the electrons pass through. What is the process of these protons moving down an electrochemical gradient called?

What is represented by molecule Y?

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. What would happen to the concentration of Acetyl Co A produced by cells exposed to IDH1?

Where does the Krebs Cycle occur?

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

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

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

How many molecules of ATP are required to generate TWO molecules of glucose ?

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

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?

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

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

The image above shows a muscle fibre. Name organelle E

The image above shows a muscle fibre. Name organelle C

The image above shows a muscle fibre. Name organelle A

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.

Using the diagram, name D

Using the diagram, name C

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

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

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

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

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

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

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

What does this experiment by Went show?

Which of the following is true?

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

Plant responses to stimuli are controlled by what?

True or false: Succession only happens on land?

Which stage represents the climax community?

What term do we use to describe lichen and mosses in succession?

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

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

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

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?

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

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?

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?

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

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

Which sex is the carrier of sex lined genes?

Which type of allele tends to be sex linked?

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

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?

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 definition of 'heterozygous'?

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 enzyme is needed in a PCR reaction ?

PCR is an example of what type of DNA amplification?

Which enzyme can join two complementary sticky ends together during genetic modification?

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

Which bond to restriction endonucleases ( restriction enzymes) break?

What do we call enzymes that cut DNA at specific base sequences?

Which enzyme do we use to convert mRNA into cDNA?

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?

What word describes the inner cell mass now?

What effect will siRNA have on expression of a gene?

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

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 polypeptide 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.

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 of the following would NOT increase your exposure to oestrogen?

If hypomethylation ( reduced methylation) happens to a tumour suppressor 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?

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 ?

Which component of a nucleotide contains nitrogen atoms?