Changes in the genetic makeup of a population

Question 1

Population genetics and variation

What is a population

Answer 1

Is a group of organisms of the same species living in a specific region at a given time

Question 2

Population genetics and variation

Define monomorphic population

Answer 2

Is one in which there exist only one variant of a trait

Question 3

Population genetics and variation

Define polymorphic population

Answer 3

Is one in which there exists more than one variant of a trait.

Question 4

Population genetics and variation

Name 4 variable characteristics group

Answer 4

Structural (ie number of toes)
Biochemical (ie dif metabolic characteristics)
Physiological (ie some people can smell substance other cant)
Behavioural (ie dif strategies of coping with stress)

Question 5

Population genetics and variation

Two types of variations
Define
-Continuous variation 🧍‍♂️
-Discontinuous variation🩸

Answer 5

• Where there are an infinite number of variant along a spectrum (eg height)
• Where there are a discrete and finite number of variants (eg blood groups)

Question 6

Causes of variation (phenotype)

First way a gene can affect ones phenotype

Monogenic traits

Answer 6

traits that are determined by purely a single gene. (specific and discrete phenotype therefore, exhibit discontinuous variation) -not effected by environment

Question 7

Causes of variation (phenotypes)

Second way a gene can affect ones phenotype

Polygenic traits define

Answer 7

Polygenic traits, traits that are controlled by many genes (may exhibit continuous or discontinuous depending on # of genes note if many genes there is environmental impact = continuous)

Question 8

Mutations

Define

• spontaneous mutation
• induced mutation

Answer 8

Occurs during DNA replication

Caused by environmental factors eg smoking

Question 9

Causes of variation (phenotype)

Environment

Answer 9

Example; Children in Africa being starved, they would be thinner and shorter than an individual who is well fed.

Question 10

Gene pool and allele frequencies

Allele define👖👽🧬

Answer 10

Each of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome.

Question 11

Gene pool and allele frequencies

Gene pool define

Answer 11

All genetic information contained within that population. (aggregation of all the alleles in all organism in a population)

Question 12

Gene pool and allele frequencies

What is the Hardy-Weinberg equilibrium 
In a given population, if...
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Therefore....Then allele frequencies will remain constant and therefore the proportion of individuals with each phenotype will remain roughly constant.

Answer 12

• Pop is large
• Mating is random and not selective
• all offspring are viable and equally fertile
• The pop is close (ie no migration)

Question 13

Gene pool and allele frequencies
Factors that affect allele frequencies

Non-random mating (selection)
Define -Natural selection
-Artificial selection

Answer 13

• Is a major mechanism by which evolution occurs- hence the well-known phrase evolution by natural selection
• instigated by humans in selective breeding

Question 14

Gene pool and allele frequencies
Factors that affect allele frequencies

Open population (migrating)

Answer 14

Migration, whether it is immigration or emigration (not a representative sample), is also known as gene flow. Gene flow can alter allele frequencies as well.

Question 15

Gene pool and allele frequencies
Factors that affect allele frequencies

Small population (genetic drift)

Answer 15

If you have small population, allele frequencies will change purely by change. This random fluctuation in allele frequencies is known as genetic drift.

Question 16

Small population (genetic drift)

Define the bottleneck effect (greatly reduce genetic diversity)

Answer 16

is the phenomenon where allele frequencies are highly volatile secondary to a sudden drop in the population ie major natural disaster (death)

Question 17

Small population (genetic drift)

Define founder effect (greatly reduce genetic diversity)

Answer 17

is the phenomenon where allele frequencies are highly variable in a small population that has emigrated from a large population and formed a new separate population.

Question 18

Define sexual selection

Answer 18

It doesn’t matter how long an individual lives but how often they reproduce.

Question 19

Mutations

Define

Answer 19

create new alleles when they occur within a gene. These mutations enter the gene pool if they can be passed on between generations.

Question 20

Mutations

Define germline mutations 🥚🍳

Answer 20

is a mutation that happens in reproductive tissue and able to pass on offspring.

Question 21

Mutations

Define somatic mutation

Answer 21

Every other mutation not reproductive therefore cannot be passed on.

Question 22

Mutations

Define the two types of mutation

• point mutations
• block mutations

Answer 22

• changes to a single base pair

- changes to entire segment of dna

Question 23

Point mutations

Define silent mutations

Answer 23

Are base substitution mutation that lead to no change in the amino acid sequence of the corresponding protein.

Question 24

Point mutations

Define missense mutations

Answer 24

Are base substitution mutations that lead to a change in the amino acid sequence by the replacement of one amino acid with another. (AAC–>ACC)

Question 25

Point mutations Define nonsense mutations

Answer 25

Are base substitutions that lead to the mutated triplet coding for stop, prematurely the amino acid sequence in the polypeptide chain.

Question 26

Block mutations Define duplication

Answer 26

Part of dna breaks off one chromosome and joins its homologous partner.

Question 27

Block mutations Define inversion

Answer 27

Is where a segment of dna is ;chopped up' and reinserted in the same place, but backwards

Question 28

Block mutations Insertion

Answer 28

Is whee a segment of dna from another molecule is copied and inserted into the middle of another segment of dna.

Question 29

Block mutations Block deletion

Answer 29

Is where a segement of dna is removed

Question 30

Block mutation Translocation

Answer 30

Is where a segment of dna from one molecule detaches and re-inserts itself in another molecule

Question 31

Natural selection

Answer 31

Darwin suggest that the process by which random evolutionary changes are selected for by nature in a consistent, orderly, non random way.

Question 32

Allopatric speciation define🌏

Answer 32

Is the phenomenon whereby a new species is formed due to the geographical isolation of two populations of the same species.

Question 33

Define species

Answer 33

Is complete set of all organism able to mate and produce viable and fertile offspring under natural conditions.

Question 34

Allopatric speciation ``` The differences in phenotypic characteristics (isolated mechanism) - - - - ```

Answer 34

- Mating calls may no longer be recognized between populations - The genitalia of the organism of two pop may be incompatible - Mating seasons may be different - Produce sterile offspring

Question 35

Selective breeding define

Answer 35

Is a method of breeding where animals with particular phenotype that are beneficial to the breeder, are allowed by the breeder to reproduce to a greater capacity than other animals of the same population.

Question 36

Selective breeding Define artificial selection

Answer 36

where breeder acts as selective pressure