KA 2

Question 1

What is evolution?

Answer 1

It is the change over time in the proportion of individuals in a population differing in one or more inherited traits

Question 2

During evolution, changes in allele frequency occur through what 3 processes?

Answer 2

The non-random processes of natural selection and sexual selection, and the random process of genetic drift

Question 3

Natural selection acts on?

Answer 3

Genetic variation in populations Variation in traits arises as a result of mutation.

Question 4

Mutation is the original source of new?

Answer 4

Alleles

Question 5

New sequences can be what kind of alleles?

Answer 5

Novel alleles.

Question 6

Most mutations are? But in some cases they may be?

Answer 6

Harmful or neutral, but in rare cases they may be beneficial to the fitness of an individual.

Question 7

Populations produce …. Offspring than the environment can support

Answer 7

More

Question 8

Individuals with variations that are better suited to their environment tend to?

Answer 8

Survive longer and produce more offspring, breeding to pass on those alleles that conferred an advantage to the next generation.

Question 9

Selection results in the?

Answer 9

Non-random increase in the frequency of advantageous alleles and the non-random decrease in the frequency of deleterious alleles.

Question 10

Sexual selection is the?

Answer 10

Non-random process involving the selection of alleles that increase the individual’s chances of mating and producing offspring

Question 11

Sexual selection may lead to?

Answer 11

Sexual dimorphism

Question 12

Sexual selection can be due to?

Answer 12

Male-male rivalry and female choice

Question 13

What is male-male rivalry?

Answer 13

Where large size or weaponry increases access to females through conflict.

Question 14

Female choice involves?

Answer 14

Females assessing the fitness of males.

Question 15

Genetic drift occurs when?

Answer 15

Chance events cause unpredictable fluctuations in allele frequencies from one generation to the next

Question 16

Genetic drift is more important for what kind of population?

Answer 16

Small populations, as alleles are more likely to be lost from the gene pool

Question 17

Population bottlenecks occur when a?

Answer 17

Population size is reduced for at least one generation.

Question 18

Population size is reduced for at least one generation.

Answer 18

Population size is reduced for at least one generation.

Question 19

Founder effects occur through the?

Answer 19

Isolation of a few members of a population from a larger population.

Question 20

The gene pool of the new population is not …… of that in the original gene pool.

Answer 20

Representative

Question 21

A gene pool is altered by? Why is this?

Answer 21

Genetic drift because certain alleles may be underrepresented or over-represented and allele frequencies change

Question 22

Where selection pressures are strong, what can be rapid?

Answer 22

The rate of evolution

Question 23

Selection pressures are the?

Answer 23

Environmental factors that influence which individuals in a population pass on their alleles.

Question 24

What are some biotic factors?

Answer 24

Competition, predation, disease, parasitism; or abiotic: changes in temperature, light, humidity, pH, salinity.

Question 25

The Hardy-Weinberg (HW) principle states that?

Answer 25

In the absence of evolutionary influences, allele and genotype frequencies in a population will remain constant over the generations

Question 26

The conditions for maintaining the HW equilibrium are?

Answer 26

No natural selection, random mating, no mutation, large population size and no gene flow (through migration, in or out).

Question 27

The HW principle can be used to determine?

Answer 27

Whether a change in allele frequency is occurring in a population over time

Question 28

Changes suggest what is occurring?

Answer 28

Evolution

Question 29

Use the HW principle to calculate?

Answer 29

Allele, genotype and phenotype frequencies in populations.

Question 30

What is the HW principle equation and what do the letters represent?

Answer 30

P2+ 2pq + q2 =1 p = frequency of dominant allele q = frequency of recessive allele p2 = frequency of homozygous dominant genotype 2pq = frequency of heterozygous genotype q2 = frequency of homozygous recessive genotype

Question 31

Fitness is an indication of?

Answer 31

An individual’s ability to be successful at surviving and reproducing

Question 32

Fitness is a measure of the?

Answer 32

Tendency of some organisms to produce more surviving offspring than competing members of the same species.

Question 33

Fitness refers to the?

Answer 33

Contribution made to the gene pool of the next generation by individual genotypes

Question 34

Fitness can be defined in what 2 terms?

Answer 34

Absolute or relative terms

Question 35

Absolute fitness is the?

Answer 35

Ratio between the frequency of individuals of a particular genotype after selection, to those before selection frequency of a particular genotype after selection frequency of a particular genotype before selection.

Question 36

If the absolute fitness is 1, then what is stable?

Answer 36

The frequency of that genotype

Question 37

A value greater than 1 conveys an increase in the?

Answer 37

Genotype and a value less than 1 conveys a decrease.

Question 38

Relative fitness is the ratio of the?

Answer 38

Number of surviving offspring per individual of a particular genotype to the number of surviving offspring per individual of the most successful genotype number of surviving offspring per individual of a particular genotype number of surviving offspring per individual of the most successful genotype

Question 39

Co-evolution is the process by which?

Answer 39

Two or more species evolve in response to selection pressures imposed by each other

Question 40

A change in the traits of one species acts as a?

Answer 40

Selection pressure on the other species

Question 41

Co-evolution is frequently seen in?

Answer 41

Pairs of species that have symbiotic interactions

Question 42

What is symbiosis?

Answer 42

Co-evolved intimate relationships between members of two different species.

Question 43

The impacts of these relationships can be? For whom?

Answer 43

Positive (+), negative (-) or neutral (0) for the individuals involved

Question 44

Mutualism, commensalism, and parasitism are types of?

Answer 44

Symbiotic interactions

Question 45

What is mutualism?

Answer 45

Where both organisms in the interaction are interdependent on each other for resources or other services. As both organisms gain from the relationship, the interaction is (+/+).

Question 46

What is commensalism?

Answer 46

Only one of the organisms benefits (+/0).

Question 47

What is parasitism?

Answer 47

Where the parasite benefits in terms of energy or nutrients and the host is harmed as the result of the loss of these resources

Question 48

The Red Queen hypothesis states that?

Answer 48

In a co-evolutionary relationship, change in the traits of one species can act as a selection pressure on the other species this means that species in these relationships must adapt to avoid extinction