Evolution & Genetics

Question 1

What is genetic redundancy

Answer 1

It refers to the fact that different codons can code for the same amino acid, as that no codon ever means two different amino acids, only one

Question 2

What’s variation

Answer 2

The difference of physical characteristics, basic function and behaviour between numbers of a species. The difference that exists between an individual or populations of a species

Question 3

What’s a mutation

Answer 3

The change in a gene or chromosome leading to new characteristics in an organisation

Question 4

Types of gene mutations

Answer 4

Deletion
Insertion
Substitution

Question 5

Types of chromosomal mutations

Answer 5

Deletion
Duplication
Inversion
Translocation

Question 6

What things can mutations occur during/due to

Answer 6

• Mutagens (chemicals, viruses, Radiation)
• DNA replication (gene mutations)
• cell division (chromosome mutations)

Question 7

What causes variation

Answer 7

Mutation (main cause)
Random fertilisation 
Migration
Recombination during meiosis
 - crossing over
 - independent assortment
 - non - disjunction

Question 8

What’s random fertilisation

Answer 8

When the sperm that fertilised the egg is unknown - therefore the DNA can’t be determined

Question 9

What’s migration

Answer 9

The movement of people from one area to another with the intention of setting permanently

Question 10

What’s crossing over

Answer 10

The interchange of the parts of the chromatids of a homologous pair of chromosomes during the first stage of meiosis. Creates a new combination of alleles

Question 11

What’s independent assortment

Answer 11

The random combination of alleles due to allele pairs separating independently of each other

Question 12

What’s non-disjunction

Answer 12

When one or more of the chromosome pairs fail to seperate during meiosis

Question 13

What’s a species

Answer 13

A group of individuals that share many characteristics and are able to interbreed and produce fertile offspring

Question 14

What’s a population

Answer 14

A group of organisms of the same species living in the same area at the same time

Question 15

What’s a gene pool

Answer 15

The sum of all alleles in the gene population

Question 16

What’s evolution

Answer 16

Change in allele frequency within a gene pool from one generation to the next

Question 17

Things that lead to evolution (mechanisms)

Answer 17

Mutation
Gene flow
Random Genetic drift
Natural selection
Isolation

Question 18

What’s gene flow

Answer 18

The movement of alleles into/out of a population, as a result of immigration/emigration

Question 19

What’s genetic drift

Answer 19

The variation in the relative frequency of different genotypes, in a small population due to chance events

Question 20

What are the principles of natural selection

Answer 20

• variation
• overproduction
• comp for resources & survival of the fittest
• high reproductive rate
• heritability
• change in allele frequency over generations

Question 21

What’s a selective agent

Answer 21

An environmental factor that kills certain animals

Question 22

Four factors that induce evolution

Answer 22

1) the potential for predations to increase in numbers
2) genetic variation as a result of mutation and sexual reproduction
3) competition for resources
4) proliferation of individuals with better survival and reproduction

Question 23

What are the disruptions to genetic equilibrium

Answer 23

Evolution
Mutation
Gene flow
Genetic drift
Nonrandom mating
Natural selection

Question 24

What’s a frameshift mutation

Answer 24

When the whole strand of DNA has been altered due to an insertion/deletion of a nucleotide base, affecting the phenotype outcome

Question 25

What’s a point mutation

Answer 25

When a mutation occurs within the nucleotide sequence but the whole strand is not affected, only the individual base/ amino acid. Phenotype isn’t affected

Question 26

What does heritability mean

Answer 26

The proportion of variation in a population trait that can be attributed to inherited genetic factors. Heritability estimates range from 0 to 1 and are often expressed as a percentage.

Question 27

What is evolution

Answer 27

The change in allele frequency within a gene pool from one generation to the next

Question 28

What leads to change in allele frequency

Answer 28

Mutation Gene flow Genetic drift Natural selection

Question 29

What’s the bottleneck effect

Answer 29

A chance event, randomly killing a large portion of the population, wiping out a large portion of the genome

Question 30

What’s the founder effect

Answer 30

When a new population of a new place is formed by that doesn’t reflect the genomes of the founding population.

Question 31

How does natural selection work

Answer 31

Overproduction + variation ``` Leads to: Natural Selection (predators + competition for recourses) ``` Leads to: Survivors passing down favourable alleles

Question 32

How does geographic isolation cause speciation

Answer 32

When a population is separated because of a geographic feature, those two subgroups of the population are no longer able to reproduce together, causing individuals of the original species to accumulate sufficient genetic differences to prevent them breeding with each other when they are reunited.

Question 33

What’s the ultimate source of variation

Answer 33

Mutations

Question 34

What are the sources of variation

Answer 34

Mutations Recombination Random fertilisation

Question 35

What are the 5 agents of change in allele frequency (resulting in evolution)

Answer 35

- mutation - gene flow - genetic drift - no random mating - natural selection

Question 36

What’s nonrandom mating

Answer 36

Mate selection influenced by phenotypic characteristics similar to the individuals, causing specific genotypes/alleles to be passed onto offspring Eg. Sexual selection- female peacock picks the male with the coolest feathers

Question 37

What is isolation

Answer 37

When two parts of a formerly interbreeding population stop interbreeding

Question 38

What causes speciation

Answer 38

- geographic isolation - temporal isolation - reproductive isolation

Question 39

Three types of bacterial enzymes used in biotechnology

Answer 39

``` Restriction enzymes (scissors) Ligation enzymes (glue) Polymerase (hands) ```

Question 40

What does a restriction enzyme do

Answer 40

Scissors- Has a recognition site (4-8 nucleotides) and cuts the DNA when it comes across a recognition site

Question 41

What do ligation enzymes do?

Answer 41

Glue- joins fragments of DNA together by forming covalent bonds between nucleotides. Can join both blunt and sticky ends (for sticky end, both DNA peices must be cut with the same restriction enzyme)

Question 42

What does DNA polymerase do?

Answer 42

Hands- assemble DNA/RNA molecules by adding complimentary base pairs to a template strand.

Question 43

DNA sequencing steps

Answer 43

- PCR - makes lots - ingredients: DNA templates, restriction enzymes, ddNTP’s, dNTP’s, primers, polymerase, different dye for each tube. - heat tubes - splits DNA - primer binds - polymerase adds nucleotide bases - when ddNTP added, terminated - polymerase can’t tell difference - variety - same for all tubes - gel electrophoresis

Question 44

Things that change allele frequency

Answer 44

- mutation - random genetic drift - gene flow - nonrandom mating - natural selection

Question 45

Factors affecting gene pools

Answer 45

Mutation Migration Genetic drift Selection pressures

Question 46

What are vestigial structures

Answer 46

Structures that have changed so much due to evolution that they no longer fulfill their original function

Question 47

What is the name of the protein that is found in all species

Answer 47

Ubiquitous proteins

Question 48

How do homologous structures show evidence for evolution

Answer 48

The more similar organisms’ anatomical resemblance, the more closely related they are

Question 49

Heterozygous advantage

Answer 49

When the heterozygous genotype has a higher relative fitness than homozygous genotypes