Genetic Variation

Question 1

Allele

Answer 1

Any of two or more variants of a gene that have the same relative position on homologous chromosomes which are responsible for alternative characteristics.

Question 2

Continuous variation

Answer 2

Variation within a species that changes gradually over a range of values.

Question 3

Diploid

Answer 3

A cell that contains two complete sets of chromosomes, one from each parent.

Question 4

Discontinuous variation

Answer 4

Variation within a species in which a trait has only a limited number of possible values / groups.

Question 5

Gamete

Answer 5

A reproductive cell having the haploid (half the number) number of chromosomes, mature egg or sperm.

Question 6

Gene

Answer 6

A sequence of DNA that occupies a specific location on a chromosome and determines a particular characteristic of an organism.

Question 7

Genetic variation

Answer 7

Variation in the allele frequency or genome between members of species, or between groups of species.

Question 8

Haploid

Answer 8

A cell that contains a single set of unpaired chromosomes (e.g. in humans it is 23 unpaired chromosomes).

Question 9

Locus

Answer 9

The position that a given gene occupies on a chromosome.

Question 10

Mutagen

Answer 10

An agent, such as a chemical, UV light, or a radioactive element, that can induce or increase the frequency of a mutation in an organism.

Question 11

Mutation

Answer 11

A permanent change in the base sequence of DNA.

Question 12

Trait

Answer 12

A genetically determined characteristic or condition.

Question 13

Somatic cell

Answer 13

Any cell of the body that is not a sexually reproductive cell.

Question 14

Silent mutation

Answer 14

Mutation that does not change the protein so has no observable effect on an organism.

Question 15

Neutral Mutation

Answer 15

A mutation that does not harm or benefit the organism.

Question 16

Beneficial Mutation

Answer 16

A mutation which gives an individual a survival advantage over the other members of its species.

Question 17

Harmful mutation

Answer 17

A mutation that has a detrimental effect on the organisms fitness (reproduction or survival).

Question 18

Deletion mutation

Answer 18

Part of the chromosome breaks off reducing the length and removing genes.

Question 19

Inversion mutation

Answer 19

Rearrangement of the genetic information on the chromosome. Does not affect length of the chromosome.

Question 20

Translocation mutation

Answer 20

Movement of genetic material from one chromosome to another. Affects the length of the chromosome.

Question 21

Duplication mutation

Answer 21

Some of the genetic material on the chromosome is copied resulting in the duplication of genes and an increase in its length.

Question 22

Gene mutations

Answer 22

Affect the arrangement of bases in the genes.

Question 23

Block mutations (chromosome mutations)

Answer 23

Affect whole genes or the arrangement of genes on the chromosome.