Genetic Variation and Change

Question 1

Heredity

Answer 1

The biological process whereby genetic factors are transmitted from one generation to the next

Question 2

Allele

Answer 2

An alternative form of a gene

Question 3

Gene

Answer 3

A segment of DNA on a chromosome that codes for a protein

Question 4

Genotype

Answer 4

Genetic makeup of an organism; an organisms combination of alleles

Question 5

Phenotype

Answer 5

An organisms appearance or other detectable characteristics that results from the organisms genotype and the environment

Question 6

Gene Pool

Answer 6

All of the alleles in all the individuals that make up a population

Question 7

Allele Frequency

Answer 7

The number of times an allele occurs in a gene pool, compared to the total number of alleles in that pool for the same gene

Question 8

Genetic Biodiversity

Answer 8

The range of all the alleles present in the gene pool

Question 9

Natural Selection

Answer 9

Process by which individuals that are better suited to their environment survive and reproduce most successfully; also called survival of the fittest

Question 10

Mutation

Answer 10

A sudden and permanent change to the base sequence of DNA

Question 11

Gene Mutation

Answer 11

A change in the sequence of the bases in a gene, which changes the structure of the polypeptide that gene codes for

Question 12

Triplet

Answer 12

The three nucleotides of DNA which code for one amino acid

Question 13

Meiosis

Answer 13

Reduction cell division that produces haploid cells for the purposes of sexual reproduction

Question 14

Somatic Cell

Answer 14

Any of the cells of a plant or animal except the reproductive cells

Question 15

Gametic Cell

Answer 15

A sex cell

Question 16

Diploid

Answer 16

An organism or cell having two sets of chromosomes or twice the haploid number

Question 17

Homologous Chromosomes

Answer 17

Chromosome pairs of the same length, centromere position, and staining pattern that possess genes for the same characters at corresponding loci. One homologous chromosome is inherited from the organisms father, the other from the mother

Question 18

Chromatid

Answer 18

One of two identical strands into which a chromosome splits during mitosis

Question 19

Centromere

Answer 19

The region of the chromosome that holds the two sister chromatids together during mitosis

Question 20

Tetrad

Answer 20

The four chromatids in a pair of homologous chromosomes that come together as a result of synapsis during meiosis

Question 21

Crossing Over

Answer 21

The exchange of genetic material between homologous chromosomes during meiosis; can result in genetic recombination

Question 22

Segregation

Answer 22

The separation of paired alleles during meiosis so that members of each pair of alleles appear in different gametes

Question 23

Independent Assortment

Answer 23

The random way in which chromosome line up and are split into the gametes. It results in genetic variation

Question 24

Autosome

Answer 24

A chromosome that is not a sex chromosome

Question 25

Monohybrid

Answer 25

Genetic crosses that involve one trait

Question 26

Complete Dominance

Answer 26

A relationship in which one allele is completely dominant over another

Question 27

Pure Breeder

Answer 27

An individual is homozygous for a trait and can only pass one type of allele to its offspring

Question 28

Incomplete Dominance

Answer 28

A condition in which a trait in an individual is intermediate between the phenotype of the individual's two parents because the dominant allele is unable to express itself fully

Question 29

Co-dominance

Answer 29

A pattern of inheritance when the two alleles of a gene are neither dominant or recessive, the two alleles are both expressed. (For example, B=black features, W=white feathers, BW=black and white features)

Question 30

Multiple Alleles

Answer 30

A gene with three or more alleles

Question 31

Lethal Alleles

Answer 31

Mutated genes that are capable of causing death

Question 32

Dihybrid Inheritance

Answer 32

A genetic cross involving genes at two different loci. The inheritance of one pair of alleles does not affect the inheritance of the other pair because chromosomes act independently of one another during gamete formation.

Question 33

Linked Genes

Answer 33

Genes located on the same chromosome that tend to be inherited together in genetic crosses

Question 34

Gamete

Answer 34

An egg or sperm sex cell that contains a single set of chromosomes, one from each homologous pair

Question 35

Genetic Change

Answer 35

Changes to allele frequencies and or the gene pool

Question 36

Gene Pool

Answer 36

Combined genetic information of all the members of a particular population

Question 37

Allele Frequency

Answer 37

The number of times an allele occurs in a gene pool, compared to the total number of alleles in that pool for the same gene

Question 38

Sexual Selection

Answer 38

A form of natural selection which individuals with certain inherited characteristics are more likely than other individuals to obtain mates

Question 39

Adaptation

Answer 39

inherited characteristic that improves an organisms ability to survive and reproduce in a particular environment