variation and selection

Question 1

natural selection

Answer 1

mechanism of evolution where organisms better adapted to their environment tend to survive and produce more offspring

Question 2

artificial selection

Answer 2

process where humans pick certain animals or plants to be breeded

Question 3

types of natural selection

Answer 3

1. stabilising selection
2. directional selection
3. disruptive selection
4. balancing selection

Question 4

stabilising selection

Answer 4

maintains favourable trait + eliminates abnormalities that are useless/harmful

Question 5

directional selection

Answer 5

alternate phenotypes have a higher chance of survival

Question 6

disruptive selection

Answer 6

selection favours extreme phenotypes than average intermediate phenotypes

Question 7

balancing selection

Answer 7

maintains multiple alleles in a gene pool of a population

Question 8

gene pool

Answer 8

total of alleles of a gene located in the reproductive cells of the individuals in any population

Question 9

factors that affect gene frequency

Answer 9

1. founder effect
2. genedict drift
3. bottleneck effect
4. gene flow
5. natural selection

Question 10

founder effect

Answer 10

loss of genetic variation when a new population is established by a small number of individuals from a larger population

Question 11

genetic drift

Answer 11

describes how allele frequencies can fluctuate unpredictably from one generation to the next

Question 12

bottleneck effect

Answer 12

a sudden change in the environment may drastically reduce the size of a population

Question 13

gene flow

Answer 13

• movement of fertile individuals or gametes which causes a population to lose or gain alleles

Question 14

charles darwin

Answer 14

• survival of the fittest
• natural selection
• competition for limited sources

Question 15

jean baptiste de lamarck

Answer 15

• changes occur over time
• inheritance of acquired characteristics
• acquired changes were passed to offspring
• law of use and disuse

Question 16

morphological structures

Answer 16

1. homolog structure
2. analog structure

Question 17

homolog structure

Answer 17

similar structure and position, but different function

Question 18

analog function

Answer 18

similar function, but different origin

Question 19

speciation

Answer 19

1. allopetric speciation
2. sympatric speciation

Question 20

allopetric speciation

Answer 20

a physical barrier makes it impossible for species to breed with one another

Question 21

sympatric speciation

Answer 21

no geographical barrier

Question 22

sympatric speciation

Answer 22

no geographical barrier