U4 T2 - Continuity of Life

Question 1

What is Evolution

Answer 1

The chane in the enetic composition of a population during succsessive generations, which may result in the development of a species.

Question 2

What is Microevolution

Answer 2

Microevolution refers to the small-scalevariation of allele frequencies within aspecies or population​

Question 3

Macroevolution

Answer 3

Macroevolution is the variation of allelefrequencies at or above the species levelover geological time, resulting in thedivergence of taxonomic groups​

Question 4

What are the three types of phenotypic selection

Answer 4

stabilising, directional and disruptive

Question 5

can the selection of allele frequency in a gene pool be positive or negative

Answer 5

Yessssss

Question 6

When does natural selection occur

Answer 6

when the pressures of environmental selection confer a selective advantage on a specific phenotype to enhance its survival (viability) and reproduction (fecundity)

Question 7

Explain Microevolution

Answer 7

Microevolution refers to the small-scalevariation of allele frequencies within aspecies or population​

Question 8

what 3 things can cause Microevolutionary change to occur

Answer 8

Mutation
Gene flow
Genetic drift

Question 9

Explain microevolutionary change through mutation,

Answer 9

Mutation is the ultimate sourceof genetic variation, as itintroduces new alleles into apopulation

Question 10

what is gene flow

Answer 10

Gene flow is the movement of genetic material between populations

Question 11

Explain microevolutionary change through gene flow

Answer 11

Gene pools can change when individualsjoin or leave a population,
Such as migration of individuals, and thealleles they carry, can result in gene flow

Question 12

Explain microevolutionary change through genetic drift

Answer 12

Genetic drift describes random fluctuations of alleles in a population over time (bottleneck effect, founder effect)

Question 13

where is genetic drift more significant and why

Answer 13

Small populations with no gene flow, as random death of one individual cansignificantly alter the allele frequencies

Question 14

what is an allele

Answer 14

The varying forms of a gene

Question 15

whats a Genotype

Answer 15

The allele makeup for a particular characteristic

Question 16

whats a Phenotype

Answer 16

the observable characteristics of an individual

Question 17

What is natural selection

Answer 17

process wherebyindividuals with the mostfavourablecharacteristics (phenotype)have an increasedchance of surviving and reproducing(fecundity), compared with individualswith lessfavourablecharacteristics.

Question 18

WHat are Selection pressures

Answer 18

external factors that affect an organism’s ability to survive in a given environment

Question 19

positive selection

Answer 19

promotes the spread of beneficial alleles

Question 20

Negitive selection

Answer 20

hinders the spread of deleterious alleles

Question 21

WHat are the 3 types of selection

Answer 21

stabilising, directional and disruptive

Question 22

When does Stabilising selection occur

Answer 22

Stabilising selection occurs when intermediate phenotypes are favoured over extreme phenotypes

Question 23

when does Directional selection occur

Answer 23

Directional selection occurs when a phenotype on one side of the bellcurve is favoured

Question 24

when does Disruptive selection occur

Answer 24

Disruptive selection occurs when extreme phenotypes on both ends of the bellcurve are favoured over intermediate phenotypes

Question 25

what does genetic drift discribe

Answer 25

random fluctuations of alleles in a population over time

Question 26

When does genetic isolation occur

Answer 26

when there is nogene flow between two populations – thegene pools are isolated from eachother

Question 27

what is Spatial isolaiton

Answer 27

occurs between populations that are separated by great distances, but it can also take place between populations that inhabit different parts of the same area.

Question 28

what are the two types of Repoductive isolation and explain them

Answer 28

Hybrid inviability-
Hybrid offspring of different species may be non-viable or show limited development

Hybrid infertility-
When interbreeding between individualsfrom different species results in offspring, theyare called hybrids and are generally sterile

Question 29

Temporal isolation

Answer 29

the misalignment of reproductive systems between indivisuals or populations

Question 30

what is Speciation

Answer 30

Speciation is the evolutionary process by which populations evolve to become distinct species.

Question 31

what are the three modes of Speciation

Answer 31

Allopatric
Sympatric
Parapatric

Question 32

how does Allopatric speciation occur

Answer 32

when ageographical barrier dividesa population

Question 33

when does Parapatric speciation occur

Answer 33

When populations maintain a zone of contact but the area is large with significant variation in habitat conditions

Question 34

when does Sympatric speciation occur

Answer 34

when there are no physical barriers preventing any members of a species from mating with another, and all members are in close proximity to one another

Question 35

What are the four patterns of Diversification

Answer 35

Divergent
Convergent
Parallel
Coevolution

Question 36

what is Divergent evolution

Answer 36

the differentiation of distinctly different species/populations from a common ancestral species

Question 37

what is Convergent evolution

Answer 37

Convergent evolution is the evolution of similarfeaturesin unrelated groups of organisms

Question 38

when does Parallel evolution occur

Answer 38

when related species evolvesimilar features independently

Question 39

when does Coevolution occur

Answer 39

two speciesevolving together in a reciprocal responseto various selection pressures

Question 40

what is the bottle neck effect

Answer 40

The bottleneck effect describes theimpact on the remaining population
Because of the reduced populationsize, the possible reproductive pairingsare limited, which leads to high levelsof inbreeding
This results in reduced variation and an increased risk of extinction
The smaller the population, the greaterthe bottleneck effect
Alleles can be lost from the gene pool