GENETICS REVIEW

A physical trait that shows as a result of an organism’s particular

genotype.

PHENOTYPE

An organism that has two different alleles

for a trait.

HETEROZYGOUS

The mathematical chance that an event

will occur.

PROBABILITY

Form of a trait that appears to

overshadow or mask another form of the

same trait.

DOMINANT

A synonym for heterozygous.

HYBRID

A characteristic of an organism controlled by

a gene.

TRAIT

Male sex cell.

SPERM

Strands of DNA and protein found in the

nucleus of a cell carrying the code for the characteristics of

an organism.

CHROMOSOME

A synonym for homozygous.

PUREBRED

A tool for predicting possible traits in

offspring.

PUNNETT SQUARE

Occurrence of a trait that makes individuals

different from members of the same

species.

VARIATION

Form of a trait that can disappear in a population but can reappear in future

generations.

RECESSIVE

Segment of DNA on a chromosome

controlling the inheritance of traits.

GENE

Female sex cell.

EGG

The different forms a gene may have for a

trait.

ALLELE

An organism that has two identical alleles

for a trait.

HOMOZYGOUS

The genetic makeup of an organism for a trait; alleles in a gene pair.

GENOTYPE

Pair of chromosomes containing alleles for

the same traits.

HOMOLOGOUS

The passing of traits from parent to

offspring.

HEREDITY

* Knowing the vocabulary is half the battle . . . You must also know how to

apply the terminology in order to answer

questions about the relationship between

parents and their offspring.

GENETICS

THE STUDY OF HEREDITY