Molecular ecology.1

Question 1

What do molecular genetic markers allow us to do?

Answer 1

To look at differences in species’ DNA which is not clearly shown by their phenotype

Question 2

Name a few examples of phenotypic variations within a population

Answer 2

eye colour and skin colour

Question 3

How has genetic variation lead to adaptation?

Answer 3

through a process of having a genetic variation being segregated, the force of natural selection has lead to selecting among the variants in populations to make them better adapted to their environment

Question 4

What is the short term importance of genetics?

Answer 4

avoiding inbreeding, fitness decrease affecting population survival

Question 5

What is the long term importance of genetics?

Answer 5

adaptation to changing conditions affecting species survival

Question 6

What is fst/fixation index?

Answer 6

A measure of population differentiation due to genetic structures estimated from genetic polymorphism

Question 7

What does it mean when the fst equals 0?

Answer 7

the populations are very similar, no genetic variation from within compared to between

Question 8

What does effective population (Ne) represent?

Answer 8

the average number of individuals in a population which are assumed to contribute genes to the next population

Question 9

What factors decrease effective population (Ne)?

Answer 9

• uneven sex, different numbers of males and females,
• variance in family size
• fluctuating population sizes
• barriers to gene flow

Question 10

What is inbreeding?

Answer 10

breeding among relatives

Question 11

What is the relationship between inbreeding and Ne?

Answer 11

inbreeding tends to decrease Ne because of less genetic variation within the population ratios

Question 12

What are the 4 main factors effecting genetic variation?

Answer 12

• selection
• gene flow
• mutation
• genetic drift

Question 13

Define gene flow?

Answer 13

the exchange of genes between populations

Question 14

Is gene flow migration?

Answer 14

No because it must involve the exchange of genes

Question 15

Define genetic drift

Answer 15

the change in allele frequency from one generation to the next caused by random sampling of alleles

Question 16

How does genetic drift change a population?

Answer 16

it changes the genetic structure of that population but no change in genetic diversity

Question 17

What is natural selection?

Answer 17

non- random differential survival due to heritable differences among organisms in their ability to survive and reproduce in the environment
change in allele frequencies over time

Question 18

Describe Darwin’s theory on natural selection

Answer 18

• advantageous mutations

- natural selection acts to preserve and accumulate minor advantageous genetic mutations

Question 19

Describe the Kimura-neutral theory on natural selection

Answer 19

all mutations are neutral therefore genetic drift plays a major role
new alleles may become more common within new population
they may decline and disappear or become fixed

Question 20

Describe the Ohta-Nearly Neutral theory

Answer 20

most mutations are neutral and teh advantageous mutations are rare
the deletiourous mutations are purged out of the population by selection

Question 21

What are mutations?

Answer 21

mistakes in replication of our genes and the transmission into the following generation

Question 22

What is the significance of mutations?

Answer 22

if mutations are occurring, its continuously giving new variants in the populations

Question 23

Name two factors that decrease genetic variation

Answer 23

natural selection and genetic drift

Question 24

Name two factors which increase genetic variation

Answer 24

gene flow and mutation

Question 25

What are allozymes

Answer 25

Variant forms of an enzyme specified by an allelic gene.

Question 26

What are restriction enzymes?

Answer 26

An enzyme that can recognize specific nucleotide sequences in DNA then cuts the DNA at a specific (restriction) site

Question 27

What are single-nucleotide polymorphisms? (SNPs)

Answer 27

most simple form and most common source of genetic polymorphism in the genome
- A singe base in the DNA differs from the usual base at that position

Question 28

What does it mean when FST =1?

Answer 28

no gene flow between the population

Question 29

What does it mean when FST =0?

Answer 29

no sub division between these populations, they are acting the same

Question 30

What is transcriptome?

Answer 30

the full range of functional RNAs or genes expressed by an organism

Question 31

What are metabolites?

Answer 31

• small molecular weight organic and inorganic biochemicals

- the building blocks for larger biochemical proteins, RNA, DNA