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Types of Traits
Next Generation: MS.LS3.2 MS.LS3.2

Types of Traits

Author: Nathan Lampson
Description:

This lesson will explain that genotypes can be either homozygous or heterozygous.

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Tutorial

 

Trait

A physical characteristic of an organism determined by genes

Allele

Different possible types of a trait

Example:

Purple flower and white flower are examples of different alleles for flower color.

Genotype

The genetic makeup of a trait

To visualize the genetic makeup of a trait, letters are used to represent different types of traits.

Example:

The letters PP are used to represent the genotype for a purple flower

Phenotype

The physical characteristic that results from a genetic trait

Example:

The purple flower

 

When an organism possesses both alleles for the same trait it is said to be homozygous.  We represent homozygous individuals with either two upper case letters or two lower case letters.

Homozygous

PP

pp

When an individual has two different alleles for the same trait, we would use one upper case letter and one lowercase letter to display their genotype.

Heterozygous

Pp