Isolation and selective breeding

Question 1

what are the two types of of isolating mechanisms

Answer 1

pre-reproductive isolation and post-reproductive isolation

Question 2

isolating mechanisms

Answer 2

mechanisms which prevent species from interbreeding to pproduce viable and fertile offspring

Question 3

example of hybrid sterility

Answer 3

horse and donkey producing amule

Question 4

why are horses and donkeys considered different species

Answer 4

because a mule cannot produce offspring due to its chromosome number being 63 (odd) so meiosis cannot occur

Question 5

morphology

Answer 5

characteristics of physical form, another way of cllassifying species

Question 6

what are the pre0reproductive isolating mechanisms

Answer 6

geogrpahical, ecological, temporal, structural, behavioural GETSB

Question 7

ecological pre-reproductive isolating mechanism

Answer 7

individuals iinhabit different ecological niches or habitats so they dont interact with each other

Question 8

geographical pre-reproductive isolating mechanism

Answer 8

individuals are uunable to interact with each other due to seperation by barriers

Question 9

temporal pre-reproductive isolating mechanism

Answer 9

the time of day/year when individuals breed differ

Question 10

behavioural pre-reproductive isolating mechanism

Answer 10

mating behaviours differ

Question 11

structural/morphological pre-reproductive isolating mechanism

Answer 11

physical characteristics differ/reproductive structures,shapes or sizes prevent mating, physically preventing breeding

Question 12

types of post-reproductive isolation

Answer 12

gamete mortality, zygote mortality and hybrid sterility

Question 13

gamete mortality

Answer 13

the sperm is unable to penetrate the ovum for fertilisation

Question 14

zygote mortality

Answer 14

fertilisation may occur and a zygote may form but it wont survive

Question 15

hybrid sterility

Answer 15

a viable offspring may form and may survive until adulthood but it will not be fertile

Question 16

selective breeding is aka

Answer 16

artificial selection

Question 17

selective breeding

Answer 17

the changing of a populations gene pool due to humans altering the breeding behaviour of animals/plants to develop a selected trait

Question 18

why is artificial insemination used

Answer 18

increases the efficiency of selective breeding

Question 19

adaptive potential

Answer 19

the ability for a population to adjust to new environmental selection pressures

Question 20

similarities between selective breeding and natural selection

Answer 20

1. requirement for variation 2. pressence of selection pressure 3. heritability of trait (also the requirements of artificial selective to occur)

Question 21

how does artificial selection differ from natural selection

Answer 21

the origin of the selection pressure, in artificial selection it is the person and the humans select which individuals mate which is different to natural selection where any pair can mate

Question 22

how does selective breeding occur

Answer 22

humans select which phenotype is more desirable and select/remove traits from a population by breeding individuals wiyh the desirbale phenotype

Question 23

artificial indemination

Answer 23

where one desirable individual can impregnate a large amount of females

Question 24

why is artificial selection bad (in animals)

Answer 24

it reduces genetic diversity which can cause inbreeding and can cause a genetic bottleneck

Question 25

genetic bottleneck

Answer 25

can genetic diversity significantly decreases in a large population due to only a small percentage of individuals expressing traits desired by humans

Question 26

what does inbreeding cause

Answer 26

increases the presence of deletrious alleles and lowers adaptive potential

Question 27

desirable trait

Answer 27

a heritable phenotype that humans select for during artificial selection

Question 28

what are the potential consequences of articifical selection in plants

Answer 28

plants may lose the ability to produce viable seeds and can only reproduce asexually, which reduces the gene pool and diversity of the population, making them vulnerable to environmental changes