Unit 7

Gregor Mendel

born in 1822/ monk in Austria who worked

           With pea plants in the monastery gardens

__**self-pollinate**__

Pea plants usually __**—-**__ – which means that pollen (sperm) fertilizes the egg of the same pea plant

__**true breeding**__, __**purebred**__.

Peas that produce offspring identical to themselves are called plants, - —-or __**——**__

__**cross pollinate**__

Pea plants can also __**- —**__, which occurs when pollen from one plant fertilizes the egg of another plant to form a seed.

__**traits**__

Mendel studied many different pea plant __**——**__or

                 Specific characteristics.

__**P generation**__

Each of the original plants were called the __**——**__, or parent generation.

F1 generation

The offspring of the P generation was called the

Hybrid

The cross between plants of different traits is called a __**—**__ cross.

__**genes And alleles**__

Inheritance of traits is controlled by __**---**__, which are inherited and that there are different forms of genes, called __**---**__

__**Principle of Dominance**__

some alleles are dominant and others are recessive. If both are present, the dominant will show itself.

F2 generation

The offspring of the F1 would be the

Genes

The inheritance of biological characteristics is determined

         By

Offspring

In organisms that reproduce sexually, genes are

         Passed from parent to

recessive.

In cases in which two or more forms of a gene for a trait

       Exist, some genes are dominant and others are

one from each parent.

In most sexually reproducing organisms, each adult has two

       Copies of a gene-

gametes form.

These genes are

       Segregated from one another when

Multiple genes

Some alleles are neither dominant or recessive, and many

            Traits are controlled by multiple alleles or

__**Incomplete Dominance**__

– when one allele is not completely dominant over another allele. The hybrid is a mix of the two traits

__**Codominance**__

when both alleles contribute to the phenotype of the organism. Both traits appear.

__**Multiple Alleles**__

– when a gene has more than two possible alleles.

__**Polygenic Traits**__

– traits controlled by the interaction of several genes.

Gene map

shows which chromosome a gene is on and the

               Location of the gene on the chromosome.

organism has

Important for genetic research and also eventually for changing the alleles an —