june 2018- paper 2 Flashcards
1
Q
why does a decrease in rubisco activity lower rate of photosynthesis (2)
A
less co2 can react with rubp
less gp forms
2
Q
why are log scales used
A
large range of numbers
3
Q
why are observed vs expected phenotypic ratios often different? (5)
A
- epistasis
- small sample sizes
- linked genes
- random fertilisation of gametes
- lethal genotypes
4
Q
how do neurotransmitters stimulate the production of a nerve impulse?
A
- diffuses across the synapse
- attaches to receptors on postsynaptic membrane
- stimulates entry of Na+
5
Q
role of 2 enzymes used to insert DNA into plasmids
A
- restriction endonuclease to cut plasmid
- ligase joins gene to plasmid
6
Q
3 structural differences that allow separation of proteins using gel electrophoresis
A
- mass
- r group
- charge
