Biology lecture 2

Question 1

If more young are born then can survive then…

Answer 1

The young will compete for limited resources

Question 2

Define Micro-Climate

Answer 2

microclimate is the long-term localized patterns of weather experienced by small communities.

Question 3

Define Macro-Climate

Answer 3

Macro-Climate is the long term localized patterns of weather experienced globally or on a landscape level

Question 4

How long does GENE FLOW DISRUPTION take?

Answer 4

The gene flow disruption (isolating mechanisms) take between 4000-40 million years.

Question 5

What is the CORIOLIS effect?

Answer 5

the coriolis effect is when air and water move clockwise in the Northern hemisphere and counter-clockwise in the southern.

Question 6

In POST-ZYGOTIC: What are the three reasons why there is reduced hybrid variability?

Answer 6

1) hybrids are steril
2) hybrids don’t live long
3) hybrids have low relative fitness

Question 7

What is meant by POST-ZYGOTIC?

Answer 7

Post-Zygotic is after fertilization, reduced hybrid variability or fertility.

Question 8

If there is unequal ability to survive and reproduce then….

Answer 8

If there is reduced ability to survive and reproduce then the population will become accumulated with favorable traits because the carriers will reproduce more than those without.

Question 9

What is the Founder Effect?

Answer 9

A small group of people reproduces to become a much larger group

Question 10

Define Pre-Zygotic

Answer 10

Pre-Zygotic prevents fertilization in the first place.

Question 11

Pre-zygotic

Three isolating mechanisms

Answer 11

1) mechanical isolation
2) behavioral/temporal/habitat isolation
3) gametic isolation

Question 12

What is mechanical isolation in Pre-zygotic?

Answer 12

mechanical isolation is where “lock and key don’t fit” the sperm cant reach the eggs.

Question 13

What is Gametic isolation in pre-zygotic?

Answer 13

Sperm and eggs come into contact but no fertilization.

Question 14

What is Behavioral/Habitat/temporal isolation in pre-zygotic?

Answer 14

They prevent mating from happening in the first place.

Question 15

Habitat isolation

Answer 15

Habitat isolation is where organisms cant mate because they have different habitats; i.e. land and sea

Question 16

Temporal Isolation

Answer 16

In temporal isolation species cannot mate because they mate at different times: seasons, hours years.

Question 17

Behavioral isolation

Answer 17

In behavioral isolation species don’t mate because they have different mating rituals.

Question 18

In natural selection what are five sources of variation?

Answer 18

1) mutation
2) double allele
3) error during meiosis
4) sexual reproduction
5) gene flow

Question 19

What are consequences for genetic variation in the Founder Effect

Answer 19

Population size may recover quickly but genetic variation carries on, bad if negative traits are passed down.

Question 20

What are three consequences of Genetic Drift?

Answer 20

1) Changes in allele frequency is random/unpredictable.
2) Low Genetic Variation makes it difficult to respond too in changing environment
3) Fixation of alleles-bad if they are harmful

Question 21

How does speciation happen?

Answer 21

When the gene-flow is interrupted and populations become separated and isolated they diverge into two reproductively different species.

Question 22

Allopatric Speciation

Answer 22

In allopatric speciation subpopulations become geographically isolated-i.e. a river, distance.

Question 23

Sympathetic Speciation

Answer 23

in sympathetic speciation, while the species may stay in the same area they still become isolated and evolve differently.

Question 24

Define Genetic Drift

Answer 24

In genetic drift the alleles fluctuate, so certain traits gradually disappear over time, limiting variation. They balance out in large populations but not in smaller ones.