Is the likelihood that something will happen.

Expressed as a decimal, percentage, or a fraction.

Genes combine according to the rules of probability• For example, the chances of an organism

being a male or female is 50%.

2Applying Mendel’s Principles

Can be used to predict the outcomes of genetic crosses.

3Applying Mendel’s Principles

Predicts the average outcome of a large number of events.• Large numbers of

offspring, will be closer to predicted values.

4Applying Mendel’s Principles

Genotype is the genetic makeup of an organism.

Phenotype is the physical appearance of an organism that is the result of its genotype.

Applying Mendel’s Principles 5

Is a simple diagram that uses mathematical probability to predict the outcome of a genetic cross.

Applying Mendel’s Principles 6

Independent Assortment Mendel

• Wondered if the segregation of one pair of alleles effects another pair.

• Performed an experiment that followed two different genes as they passed from one generation to the next.

• This experiment is known as a two-factor, dihybrid, cross. Single gene crosses are monohybrid crosses.

Independent Assortment Mendel crossed

true-breeding round yellow peas with wrinkled green peas.• All of the F1 offspring

produced round yellow peas.

Independent Assortment The alleles for

yellow round peas were dominant over the alleles for green wrinkled peas.• This result did not

support the independent assortment of genes.

Independent Assortment Mendel crossed the

F1 plants to produce F2 offspring.• This produced offspring

that had phenotypes that were not found in their parents.

This meant that genes that segregate independently do not influence each other’s inheritance.

Appyling Mendel’s Principles 11

Principle of Independent Principle of Independent Assortment:Assortment:

States that genes States that genes for different traits for different traits segregate segregate independently independently during the during the formation of formation of gametes. gametes.

A Summary of Mendel’s Principles

The inheritance of biological characteristics is determined by individual units called genes, which are passed from parents to offspring.

Where two or more forms (alleles) of the gene for a single trait exist, some forms of the gene may be dominant and others may be recessive

A Summary of Mendel’s Principles

In most sexually reproducing organisms, each adult has two copies of each gene—one from each parent. These genes segregate from each other when gametes are formed.

Alleles for different genes usually segregate independently of each other.

Practice Quiz for Mendel's Practice Quiz for Mendel's GeneticsGenetics

http://anthro.palomar.edu/mendel/quizzes/mendqui1.htm