Genetic variation

Question 1

what is a gene pool

Answer 1

all the genes in a population

Question 2

what is a population

Answer 2

a group of individuals from the same species that interbreed

Question 3

what is drift

Answer 3

changes frequency via random sampling

Question 4

what are traits

Answer 4

variants of phenotypic character(s) of an organism that may be inherited, determined by the environment, or by both and are visible

Question 5

what is a polymorphic loci

Answer 5

any locus that has more than one allele present within a population

Question 6

what is QTLs

Answer 6

Quantitative Trait Loci

Question 7

what is heterosis

Answer 7

hybrid vigour

Question 8

what is genetics

Answer 8

study of heredity

Question 9

how are genes passed on

Answer 9

gene passes from one generation to the next, dictates the inherent properties of a species

Question 10

what are genes

Answer 10

functional units of chromosomes

Question 11

what is the discipline of genetics

Answer 11

1. transmission genetics e.g. peppered moths - due to change in environment
2. molecular genetics
3. population genetics
4. quantitative genetics e.g. height in humans, many genes affect this

Question 12

what is genetic variation

Answer 12

variations of genomes between members of species, or between group of species thriving in different parts of world – result of genetic mutation

Question 13

what is genetic diversity

Answer 13

diversity in a population or species is a result of a new gene combinations, genetic mutations, genetic drift etc.

Question 14

what is the importance of genetic variation

Answer 14

• maintain biodiversity among species
• selection of strongest individuals to guarantee species survival, leading to evolution
• pool of genes pass to next generations

Question 15

why is genetic variation important to study

Answer 15

• in any form of breeding, natural or artificial, variation must be present for desired characteristics
• whatever the breeding system the selection of the “parents” is very important – they must show the required variation

Question 16

what are the two main sources of genetic variation

Answer 16

natural

induced

Question 17

what are the natural sources of variation

Answer 17

intra-specific

inter-specific

Question 18

what are the induced sources of variation

Answer 18

1. polyploidy
2. mutagens
3. genetic engineering

Question 19

what is divergence of populations

Answer 19

Patterning of genetic variation in and between populations is dynamic process
Loss/fixation of variations via drift and creation of new genetic variation via mutation (and perhaps migration) is a constant background process
Populations can also evolve via natural selection to be locally-adaptive

Question 20

what causes genetic divergence

Answer 20

• drift and mutation cause allele frequencies to change between populations
• breeder usually interested in those genetic changes made by natural selection and exploits genetic adaptation and genes that underlay these adaptive traits

Question 21

what is intra-specific variation

Answer 21

range of genetic information available among all individuals of a species
survival of fittest ensures gene pools of natural variation exist in natural populations e.g. different in natural populations, i.e. different genes in different environments

Question 22

what is inter-specific genetic variation

Answer 22

range of genetic information available of related species that don’t normally sexually reproduce together

Question 23

what is inter generic genetic variation

Answer 23

range of genetic information available of different GENERA that don’t normally sexually reproduce together (e.g. sheep and goats)

Question 24

what is inter familal genetic variation

Answer 24

range of genetic information available of different FAMILIES that don’t normally sexually reproduce together, extremely rare (e,g, guineafowl hybrids)

Question 25

what is polyploidy

Answer 25

increase of complete sets of chromosomes; usually induced with chemicals (colchicine)

Question 26

what is genetic engineering

Answer 26

manipulation of DNA of organisms, change inheritance or in vitro manufacture of gene products. Introduction of new DNA doesn’t use classical genetic methods, traditional breeding methods are typically used for the propagation of recombinant organisms

Question 27

how is genetic variation measured

Answer 27

1. phenotype:
   > proportion of polymorphic loci
   > Heterozygosity (H)
2. protein electrophoresis

Question 28

how is genetic variation quantified

Answer 28

statistics (ANOVA)

Question 29

how is genetic variation measured

at protein level

Answer 29

protein electrophoresis

could quickly determine genotypes of many individuals at many loci

Question 30

what is protein electrophoresis

Answer 30

proteins separated as they move through a gel matrix according to charges of amino acids

Question 31

problem with protein electrophoresis

Answer 31

may miss much of the variations due to silent or synonymous variations

Question 32

what are synonymous changes

Answer 32

change at site that don’t change amino acid sequence of resulting protein

Question 33

what are non-synonymous changes

Answer 33

changes occur at nucleotides that change the amino acid sequences of resulting protein

Question 34

why are there large amounts of nucleotide diversity at synonymous sites

Answer 34

because the changes do not affect the function of a protein

Question 35

how is genetic variation at DNA level measured

Answer 35

DNA sequence variations can be detected by

1) gel electrophoresis
2) restriction enzymes

Question 36

what are the patterns on gels called

Answer 36

restriction fragment length polymorphisms (RFLPs)

Question 37

what information does the patterns on gels provide

Answer 37

RFLPs can be used to provide information about how DNA sequences differ among individuals