he·red·i·ty

Noun

(hə red’ ə tē)

•The genetic transmission of characteristics from parent to offspring.

•One's genetic constitution.

•The sum of the qualities and potentialities genetically derived from one's ancestors

•The passing of traits from parents to offspring

gene Noun 

(jēn)

A portion of a DNA molecule that serves as the basic unit of heredity. Genes control the characteristics that an offspring will have by transmitting information in the sequence of nucleotides on short sections of DNA.

Segments of DNA that carry hereditary instructions and are passed from parent to offspring: located in chromosomes.

Traits

 

a distinguishing quality that can be passed from one generation

to another

dominant trait

adjective noun 

(Däm’ə nənt trāt)

In genetics, a trait that will appear in the offspring if one of the parents contributes it.

Example: In humans, dark hair is a dominant trait; if one parent contributes a gene for dark hair and the other contributes a gene for light hair, the child will have dark hair.

The trait observed when at least one dominant allele for a characteristic is inherited

recessive trait adjective noun

(ri ses’iv trāt)

In genetics, a trait that must be contributed by both parents in order to appear in the offspring. Recessive traits can be carried in a person’s genes without appearing in that person.

For example, a dark-haired person may have one gene for dark hair, which is a dominant trait, and one gene for light hair, which is recessive. It is thus possible for two dark-haired parents to have a light-haired child, provided each parent contributes a gene for light hair.

A trait that is apparent only when two recessive alleles for the same characteristic are inherited

alleles

noun (ə lēl’)

The different forms of a gene. Y and y are different alleles of the gene that determines seed color. Alleles occupy the same locus, or position, on chromosomes.

Different forms of a single gene

genotype noun

(jen’ə tīp)

The genetic constitution of an organism with respect to a trait. For

a single trait on an autosome, an individual can be homozygous for

the dominant trait, heterozygous, or homozygous for the recessive trait.

Yellow seeds are dominant, but yellow seeded plants could have a

genotype of either YY or Yy.The inherited combination of

alleles

homozygous adjective

(hō-mŏ-zīgəs)

Both alleles for a trait are the same in an

individual. They can be homozygous dominant (YY), or homozygous

recessive (yy).

heterozygous adjective (hĕt ə-rō-zīgəs)

Differing alleles for a trait in an individual, such as Yy.

phenotype noun

(fē’nə-tīp’)

The physical appearance of an organism with respect to a trait, i.e. yellow (Y) or green (y) seeds in garden peas. The dominant trait is normally represented with a capital letter, and the recessive trait with the same lower case letter.

An organism’s inherited appearance

Incomplete dominance

sometimes a trait is not completely dominant

over another, however these traits do not

blend, but each allele has its own degree of

influence

Inherit

to receive characteristics from

parents  

Probability

the mathematical

chance that an event will occur