definitions

Question 1

triplet code

Answer 1

3 bases code for an amino acid

Question 2

genetic bottleneck

Answer 2

large reduction in population size due to natural disaster, low number of individuals so low variety of alleles meaning less genetic diversity.

Question 3

haploid

Answer 3

cells have half the number chromosomes

Question 4

diploid

Answer 4

cells have full set of chromosomes

Question 5

surface area: volume

Answer 5

for exchange to be efficient, an organic needs a large surface area to volume ratio

Question 6

spiracles

Answer 6

pores on the body surface of insects that open and close to allow gases to diffuse in and out

Question 7

gill lamella

Answer 7

parts of fish gills that increase the surface area and where the blood flows through for gas exchange

Question 8

countercurrent flow

Answer 8

blood and water flow in opposite directions to maintain a diffusion gradient across whole gill length

Question 9

stomata

Answer 9

pores in the underside of a leaf that can be opened and closed by guard cells