Ppq 2006

Question 1

What would result from an increased production of ADH

Answer 1

The production of urine with a higher concentration of urea

Question 2

What are the 2 substances needed for the Calvin cycle other that GP,TP, and RUBP

Answer 2

Glucose and co2

Question 3

What is the role of ATP in photosynthesis

Answer 3

Provides energy for photolysis, and the Calvin cycle

Question 4

Explain Why from the light dependent stage of photosynthesis is needed by the Calvin cycle

Answer 4

For the reduction of GP to TP

Question 5

Describe the role of oxygen in aerobic respiration

Answer 5

It is used as the final hydrogen acceptor

Question 6

What are 2 Functions of TRNA in protein synthesis

Answer 6

To bring anticodons to their specific codons and to carry amino acids to the ribosome

Question 7

Genetic information for protein synthesis is in the form of a triplet code explain what is meant by this statement

Answer 7

3 nucleic bases which hold genetic information to code for one amino acid

Question 8

Explain why their is a risk of rejection when tissues are transplanted

Answer 8

Antibodies are produced by lymphocytes which are made against the transplant because transplant tissues have native/foreign proteins

Question 9

Suppressor drugs act by binding to DNA Molecules in such way that the separation of two DNA is prevented, predict one possible consequence of this type of drug on the normal functions of DNA

Answer 9

DNA cannot replicate as usual and no cell decision will occur

Question 10

Explain how an inherited chromosome mutation may result in an altered phenotype

Answer 10

Essential proteins are not made and different proteins are made instead / the amino acid sequence has changed

Question 11

Why are makes more likely to be affected by a mutation than woman

Answer 11

Males only need one copy/ allele to be affected by it but females need 2 copies

Question 12

Bird species must forage economically

- explain what is meant by this statement in terms of energy gain and loss

Answer 12

Energy gain must be more than the energy lost by the birds in order to survive / there must be an overall net gain

Question 13

Suggest two reasons why the actual numbers observed may be different from expected numbers in a dihybrid cross

Answer 13

Mutation/ crossing over/ independent assortment or gene / sex linkage

Question 14

What is meant by long day plants

Answer 14

There is flowering when hours of darkness is below a certain level

Question 15

What are two substances needed for DNA replication

Answer 15

enzymes and ATP

Question 16

What is the importance of crossing over in meiosis

Answer 16

It increases variation

Question 17

What is the role of vitamin D in humans

Answer 17

Controls the absorption of calcium by the intestine

Question 18

Why can PKU sufferers still develop some pigment in their skin

Answer 18

They gain tyrosine from food/ their diet and can be converted to pigment

Question 19

What is the role of thyroxine in the human body

Answer 19

Controls and speeds up metabolism

Question 20

The action spectrum in photosynthesis is a measure of the ability of photosynthetic pigments to

Answer 20

Use light of different wavelengths for synthesis