exam questions Flashcards
1
Q
why meiosis necessary in testes?
A
- to produce sperm
- for sexual reproduction
- to produce haploid cells
- so when fertilization occurs, the number of chromosomes return to diploid number
- creates genetic variation
2
Q
why plants store starch
A
- energy store
- source of energy when plants cant photosynthesise
3
Q
outline the pathway in a reflex arc in response to shining a bright light in eye
A
- stimulus detected by retina’s receptors
- electical impulse sent via optic nerve
- sensory neurone –> relay neurone –> motor neurone
- synapses between neurones allow impulse to travel in one direction only
- effector which is circular muscles in iris contract, radial relax
- pupil becomes smaller
4
Q
how a structure of a neurone is related to its function?
A
- long - to transmit pulse over a long distance faster
- mitochondria to release energy for transmission impulse / protein synthesis / active transport / making neurotransmitters
- vesicles to carry neurotransmitter
- neurotransmitters released across a synapse
- receptor proteins allow unidirectional transmission
