B20 Variation and selection

Question 1

Natural selection

Answer 1

a mechanism of evolution that results in the organisms within a population becoming best adapted for their environment due to them surviving, reproducing and passing their alleles onto their offspring

Question 2

continuous variation

Answer 2

influenced by genes and environment, resulting in a range of phenotypes. E.g height

Question 3

discontinuous variation

Answer 3

caused by genetics alone and results in a limited number of distinct phenotypes with no intermediates. E.g blood type

Question 4

mutation

Answer 4

a change in gene or chromosome

Question 5

variation

Answer 5

the differences that can be seen within a species

Question 6

examples of inherited/heritable characteristics

Answer 6

fur color, tail length, eye color, size, limb length

Question 7

examples of environmental/ acquired characteristics

Answer 7

scars, language, skills, behavior

Question 8

antibiotics

Answer 8

chemicals that kill bacteria.

Question 9

how do strains of antibiotic bacteria develop?

Answer 9

through natural selection- there is a resistant variety amongst the bacteria, and when they are bathed in antibiotics, the normal bacteria die. The resistant bacteria multiply and become more common.

Question 10

Why should you always finish a course of antibiotics?

Answer 10

all the bacteria might not have been killed, which allows there to be opportunity for the bacteria to evolve into a more resistant strain

Question 11

artificial selection/ selective breeding

Answer 11

when humans decide which characteristics are passed down to the next generation

Question 12

the effect of ionising radiation and the rate of mutation

Answer 12

increases mutation rate- increases rate at which genes can be altered.