Chapter 4 7th Grade

Phenotype

An organism's physical appearance, or visible traits. (your eye color)

Allele

Different forms of a gene; different forms of alleles form different traits (ex. blue eyes)

Hybrid

Offspring of crosses between parents with different traits (ex. Tall plant crossed with a short plant giving you the genotype Tt)

simple dominance

a pattern of inheritance in which there are only two alleles, and the dominant trait is always expressed in a hybrid organism (Tt is a hybrid plant with the dominant Tall (T) allele and short (t) allele which is recessive)

dominant trait

according to Mendel's simple dominance theory, a recessive trait is hidden by a

Allele for dominate trait always represented by

an uppercase letter

An example of a phenotype is

black fur

Genotype

genetic makeup (ex: TT, Tt, or tt)

A (Tt) genotype is said to be

hybrid

Alleles for recessive traits are represented by

lowercase letters

The genotype always determines the organisms

phenotype

A (TT) genotype is said to be:

purebred

Heredity

the study of how traits are passed from one generation to the next