Genetic Make-up

Question 1

Selection Pressure

Answer 1

environmental factors which determine whether an organism will be more or less successful at surviving and reproducing

Question 2

Gene Pool

Answer 2

the sum total of all the alleles present in a population at any one time.

Question 3

Mutation

Answer 3

cause changes in the sequence of DNA, leads to changes of proteins or new alleles

Question 4

Gene Mutations

Answer 4

affect the base sequence of a single gene

Question 5

Chromosomal Mutations

Answer 5

changes in the structure of a chromosome involving large pieces being rearranged,

Question 6

Aneuploidy

Answer 6

loss or gain of whole chromosome

Question 7

Polyploidy

Answer 7

loss of gain of complete sets of chromosomes

Question 8

Point Mutations

Answer 8

gene mutations involving a single nucleotide

Question 9

Missense Substitution

Answer 9

single base substituted by another

Question 10

Nonsense Substitution

Answer 10

single base substituted by another

Question 11

Reading Frame Shift by Insertion

Answer 11

single base is inserted, disrupting the reading sequence for all those after.

Question 12

Partial Reading Frame Shift

Answer 12

single base is inserted and another is deleted at a different location. Causes localised frame shift

Question 13

Deletion

Answer 13

break occurs at two points on the chromosome and the middle piece falls out, two ends rejoin to form chromosome deficient in some genes

Question 14

Translocation

Answer 14

movement of a group of genes between different chromosomes. Piece of one breaks off and joins another.

Question 15

Inversion

Answer 15

middle piece of the chromosome falls and, rotates 180 and rejoins.

Question 16

Duplication

Answer 16

segment is lost from one chromosome and added to its homologue.

Question 17

Gene Flow

Answer 17

movement of genes into or out of a population (immigration and emigration)

Question 18

Genetic Drift

Answer 18

random fluctuations in the frequency of alleles from generation to generation due to chance events

Question 19

Population Bottlenecks

Answer 19

environmental event that drastically reduces the size of a population

Question 20

Founder Effect

Answer 20

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

Question 21

Natural Selection

Answer 21

process by which populations of living organisms adapt and change, selectively altering genetic variation through differential survival and reproduction

Question 22

Allopatric Speciation

Answer 22

formation of a new species from pre-existing species, occurring when a geographical barrier physically isolates populations of an ancestral species

Question 23

Selective Breeding

Answer 23

occurs when man directly intervenes in the breeding of animals to produce desired traits in offspring