Speciation full

Question 1

Evolution

Answer 1

change of gene pool of a pop over tine

Question 2

Gene Pool

Answer 2

All genetic alleles present in a population

Question 3

Allele Frequency

Answer 3

The occurrence of allele/total amount of allele present
How common an allele occur in a population

Question 4

Mutation

Answer 4

It is a permanent change in the base sequence of DNA that may result in new alleles being formed. The only way new alleles are formed.

Question 5

I can discuss the relationship between allele frequency and evolutionary change

Answer 5

it is influenced when the enviro changes and it will affect mutant alleles. For instance, if an evolutionary change leads to the emergence of a mutant allele and it undergoes natural selection, successful survival boosts the mutant allele’s reproductive success and frequency. Conversely, if the mutant allele doesn’t survive, the opposite occurs.

Question 6

I can define genetic drift

Answer 6

Random change in allele frequency of population over time

Question 7

I can discuss how genetic drift changes a gene pool

Answer 7

due to certain alleles caused by random events made them less common in a population over time - less genetic diversity.

Question 8

I can define the founder effect

Answer 8

Founder effect is when a small number of a population moves and establishes a new population carrying small amount of genetic variation present in the original population - more gd

Question 9

I can define the founder effect
I can explain how the founding population will likely have a different gene pool to the large population

Answer 9

as the new population is isolated from the larger population, founder effect occurs, meaning that the genetic makeup of the new population is not an representative of the orginal population therefore different genepool with different allele frequencies.

Question 10

I can explain how migration changes allele frequency in a population

Answer 10

individuals mirgating out of a population will have lesser alleles compared to the orginal population causing both population to be unstable with less alleles with a reduced gv.

Question 11

I can explain what stabilising selection is

Answer 11

is when the middle range is more favoured and the outer two extreme like the left and right extreme are selected against

Question 12

Directional selection

Answer 12

is when there are two extreme, the favoured phenotype will be selected for and the allele frequency will shift in one direction.

Question 13

Two types of polyploidy:

Answer 13

Autopolyploidy
Individuals with more than 2 sets of chromosomes from the same species, this occurs through failure of cell division during meisosi/mitosis (chromosome doubling)n

Allopolypoidy
individuals has more than 2 sets of choromsomes from different species occurred through hybrization between two different species (chromosome doubling)

Question 14

I can discuss how polyploidy can result in instant speciation/non-disjunction.v

Answer 14

opccurs when meiossi spindles pulls incorrect numer of number of chromosomes to the wrong end of the pole resulting in gamates having more or less chromosome than normal. This result in non-disjuntion and may cause gamtes having 2n. The fusion of
diploid gametes is a form of instant speciation.

The offspring have different chromosome numbers than their parents, so are unable to breed with their parent species due to not having homologous pairs.

Question 15

Disruptive selection

Answer 15

an natural selection where the middle extreme is selected against and the two outer extremes are more favoured:

Question 16

I can define reproductive isolating mechanisms [23]

Answer 16

Is a mechanism factor that prevents interbreeding between different population and species.

Question 17

Hybrid inviability

Answer 17

Hybrid offspring dies in early development
due to genes of both parents are incompatible)

Question 18

Hybrid sterility

Answer 18

the hybrid offspring reaches maturity but is infertile so cannot breed.

Question 19

Hybrid breakdown

Answer 19

Hybrid or springs arefertile now by as generation passes by there be less fertile due to birth defects in embrtoytic stage

Question 20

What are advantages of polyploidy?

Answer 20

1. increased fitness of hybrid offsprings compared to the fitness of their parent- more larger
2. increased Genetic Diversity - get beneficial traits and pass on { wider range of traits and adaptations advantageous in changing environment.

Question 21

Allopatric Speciation/ 2 things required and the impacts.

Answer 21

Speciation occurs due to geographical barriers, or geographical isolation.
1. No inbreeding between populations
2. Gene pool must stay isolated

impact:
Populations in different geographical locations will have different selection pressure to faceOvertime heritable traits in each population will change until populations are different and distinct.

Question 22

Sympatric Speciation

Answer 22

formation of a new species from parent species in the same location / different niche.

Question 23

Convergent

Answer 23

is when two or more unrelated species develop similar functions due to selection pressurees

Question 24

Analogous structure

Answer 24

different orgins but similar
functions

Question 25

Divergent evolution

Answer 25

Evolutionary process in which an ancestral species is split into 2 or more species due to different selection pressures.

Question 26

Homologous structure

Answer 26

are structure that are similar and are from similar orgins but different functions

Question 27

Adaptive radiation

Answer 27

A type of divergent evolution where one ancestral species splits into many new species rapidly adapted to several new niches.

Question 28

co evolution

Answer 28

Is when two or more species evolve in response to each others selection pressure, contributing to GD

Question 29

Puncuated Equilbirum

Answer 29

A rate of evolution, where periods of rapid evolution interrupted by periods of little change/stasis

Question 30

Gradualism

Answer 30

slow changes between populations over time where small changes accumulate over time to produce major evolutionary transition

Question 31

How can polploidy lead to speciation

Answer 31

polyploidy inviduvals may be reproductively isolated from their parent species due to differences in chromosome number preventing successful mating and reproductions leading to new species being reproductively isolated from its parent species.

Question 32

(aka reproductive isolation)
How does isolation of populations creates new formation of species:

Answer 32

If two populations are isolated, individuals from one population cannot migate to the other population. This prevents the possibility of breeding and therefore gene flow; the two factors needed for the formation of a new species. Selection pressures ARE unique to one population and would affect that gene pool only. Isolation of populations + different selection pressures = formation of a new species.

Question 33

Parrell evolution

Answer 33

species share a common ancestor (but not related) but envovlve in similar ways independent of other species )

Question 34

Post-zygotic RIMS?

Answer 34

Reproductive isolating mechanisms which prevent gene flow by acting when the egg is fertilised.

Question 35

What is behavioural isolation?

Answer 35

Reproductive barriers due to difference in mating behaviours.

Question 36

What is temporal isolation?

Answer 36

Difference in breeding behaviour, such as time for breeding and breeding seasons.

Question 37

What is Ecological Isolation

Answer 37

The difference in the habitat within the same geographical location that prevents populations from coming into contact

Question 38

What is Gametic isolation?

Answer 38

Eggs from one population are incompatible with the sperm of the other, preventing fertilisation from occurring.

Question 39

Pre-zygotic RIMS?

Answer 39

Reproductive isolating mechanisms

which prevent gene flow before the egg is fertilised (before the zygote is formed).

Question 40

speciation

Answer 40

The formation of new species as a result of evolution