2017 Biology Paper 2

Question 1

How can neutrophils be identified in a blood smear?

Answer 1

Neutrophils have a highly segmented nucleus.

Question 3

What is the difference between conservation and preservation?

Answer 3

Preservation is maintaining habitats and ecosystems in their present state, minimising human impact.

Conservation is a more active management process involving human intervention.

Question 4

For what reason, other than epistasis, might a phenotype ratio be different to what is expected?

Answer 4

Autosomal linkage:
* both genes occur on the same chromosome
* so alleles are inherited together
* unless crossing over occurs between loci

Question 5

Why is an individual not affected by a recessive genetic disease if they are heterozygous?

Answer 5

The protein will still be synthesised even with only one of the dominant alleles.

Question 6

How can plants respond to infection?

Answer 6

• production of callose
• production of toxic chemical
• abscission
• necrosis

Question 7

Why can respiratory substrates be used in respiration?

Answer 7

• Bonds contain energy.
• These bonds can be broken by respiratory enzymes.

Question 8

What protein makes the cell membrane of E. coli permeable to lactose?

Answer 8

lactose permease

Question 9

What is the name of the gene that is added to a plasmid to allow recombinant bacteria to be identified?

Answer 9

Marker gene