Species and Speciation

Question 1

Biology species concept

Answer 1

population where individuals can make fertile, healthy babies
limitations: can’t use it on all prokaryotes and asexual organisms

Question 2

reproductive isolation

Answer 2

biological barrier that stops two different species from mating or from making healthy, fertile babies

Question 3

Two types of reproductive barriers

Answer 3

1. prezygotic barriers

2. postzygotic barriers

Question 4

1. prezygotic barriers

Answer 4

1. habitat isolation
2. temporal isolation
3. behavioural isolation
4. mechanical isolation
5. gametic isolation

Question 5

1. habitat isolation

Answer 5

species live in same environment but occupy different parts of it

Question 6

2. temporal (time) isolation

Answer 6

make babies at different times of day, different seasons, different years

Question 7

3. behavioural isolation

Answer 7

species attract their mates differently from one another

Question 8

4. mechanical isolation

Answer 8

will try to mate but can’t because of their morphology

Question 9

5. gametic isolation

Answer 9

sperm of one species can’t fertilise the other. sperm could get destroyed in female tract

Question 10

Postzygotic barriers

Answer 10

1. reduced hybrid viability
2. reduced hybrid fertility
3. hybrid breakdown

Question 11

1. reduced hybrid viability

Answer 11

even though mating was successful the hybrid might die while developing or won’t develop properly

Question 12

2. reduced hyrbrid fertility

Answer 12

hybrid won’t be infertile
genes can’t flow between species
can’t make normal gametes

Question 13

3. hybrid breakdown

Answer 13

hybrid can be fertile and healthy but when it tries to reproduce with mate from one of the parent species it can’t because it will make unhealthy and infertile babies

Question 14

Morphological species concept

Answer 14

establish species according to their structural features or body shape
limitation: which structure would you choose? you’d have to agree on one

Question 15

ecological species concept

Answer 15

establishing species according to their ecological niche
you can use it on asexual and sexual organisms
focuses on disruptive selection

Question 16

Speciation can happen two ways

Answer 16

1. allopatric speciation

2. sympatric speciation

Question 17

allopatric speciation

Answer 17

population is separated by geographic barrier
gene flow can’t happen anymore
because of that there will be reproductive isolation instead of adaptive selection
when population is separated populations evolve independently by
1. natural selection
2. point mutation
3. genetic drift

Question 18

sympatric speciation

Answer 18

population that’s not divided by a physical barrier but by biological ones
if gene flow is reduced it’s because of :
1. polyploidy
when error occurs during cell division = extra set of chromosomes
2. sexual selection
3. habitat differentiation

Question 19

1. polyploidy

Answer 19

1. autopolyploidy
   more than 2 sets of chromosomes from 1 species
2. allopolyploidy
   can mate but can’t make babies with either parent species

Question 20

2. sexual selection

Answer 20

females choose males

mates will have different colours

Question 21

3. habitat differentiation

Answer 21

new ecological niche could appear

Question 22

Hybrid zones

Answer 22

space where 2 different species mate

species with incomplete reproductive barriers mate