Evolution- Darwin And The Modern Synthesis

Question 1

Define transmutation of species

Answer 1

Altering of one species into another

Question 2

How did finches adapt to different habitats

Answer 2

Different beaks

Question 3

Outline Thomas Malthus Populations

Answer 3

Populations have tremendous growth potential but resources are limited

Question 4

Define fitness

Answer 4

The differential survival and reproduction of individuals due to differences in phenotype

Question 5

Outline Darwin’s 4 theories for natural selection

Answer 5

-Individuals within species are variable because of mutations in DNA creating new alleles and subsequent shuffling of alleles
-some of the variations are passed on to offspring- genes/alleles are passed on to offspring in fact and often independently of other genes
-in most generations, more offspring are produced than can survive
-survival and reproduction are not random: individuals with the highest reproductive success are those with the most favourable variations with alleles and allelic combinations that best adapt them to their environment - they are ‘naturally selected’

Question 6

Define evolution

Answer 6

Terms of changes in allele and gene frequencies over time

Question 7

Define altruistic behaviour

Answer 7

No. Survival or reproductive advantage to the adult- eg, parents feeding child

Question 8

Define altruism

Answer 8

Selection operation on alleles in relation to their average contribution to their own transmission through their action on the individuals that carry them
-the same alleles will be present in close relatives

Question 9

Outline the assumptions of the HW equilibrium
(If an allele population is not in HW)

Answer 9

-no sex linkage
-random mating
-mutations does not occur
-migration is negligible
-population size is large
-no selection
-there is no consanguinity

Question 10

What is HW used for

Answer 10

Used to predict the number of each genotype/allele frequencies from the allele/genotype frequencies

Question 11

What is the HW equation

Answer 11

P^2+2PQ+Q^2=1
P=dominant
Q= recessive

Question 12

Define the founder effect

Answer 12

The loss of genetic variation that occurs when a new population is established by a very small number of individuals

Question 13

Define genetic bottlenecks

Answer 13

A sharp reduction in the size of a population over several generations

Question 14

How do prokaryotes differ from eukaryotic evolution

Answer 14

-chromosomes -> singular circular DNA (haploid)
-plasmids-> occur naturally, important in antibiotic resistance

Question 15

Defined conjugation

Answer 15

Plasmids can pass between different species by horizontal gene transfer through a sex pilus

Question 16

Define transformation regarding prokaryotes

Answer 16

Bacteria can take up free DNA and integrate into their genome

Question 17

Define transduction regarding prokaryotes

Answer 17

Transfer of DNA through phases (virus of bacteria)

Question 18

When does an allele have a selective advantage

Answer 18

When it makes the organism possessing it more likely to survive and reproduce

Question 19

Definition of an allele

Answer 19

Alternative version of an allele

Question 20

Outline genetic drifts for small populations

Answer 20

By chance an allele could be transmitted to a high proportion of offspring: if an allele is lost- it’s extinguished (other allele is fixed)

Question 21

Outline genetic drifts for large populations

Answer 21

Allele frequencies change more slowly