Biology genetics

Gene

Segment of DNA that controls a heredity trait

Allele

Different forms of the gene that produce distinguiable traits in offspring

Homozygous

The two alleles are the same

Heterozygous

The two alleles are different

Genotype

genetic makeup of an organism

Phenotype

physical characteristics of an organism

Dominant Allele

Capital letter, over powers recessive

Recessive Allele

Lower case, takes two for phenotype to appear

Parental Genotype

Each parent has 2 alleles for a particular trait 1 is passed to offspring

F1 generation

the first generation of offspring obtained from an experimental cross of two organisms

F2 generation

offspring of the F1 generation

incomplete dominance

not controlled by domaint or recessive but appears in between or mixed

Codominance

Neither allele is domaint or recessive, both contribute to the phenotype

Trait

a distinguishing quality or characteristic

multiple alleles

A gene that has more than two alleles

polygenic inheritance

interaction of many genes

3 basic laws of Mendel's inheritance

Law of domainant and recessive

Principal of segration

Principle of independent assortment

3 exceptions of Mendels laws

Some alleles are neither domaint or recessive

Most genes have more than 2 alleles

Some traits have more than one gene

Why are sex linked genetic orders more common in males

only need one recessive gene

difference between germ cell and somatic cell

germ: mutation in organisms gametes

Somatic:Mutation in organisms body cells

importance in mutations

change of phenotype of the organism that makes them better suited for its enviroment

What are the different types of chromosome mutations

deletion, inversion, translocation, nondisjuction

What is the mutation that most commonly causes down syndrome

nondisjuctional

Is crossing over during meiosis considered a mutation why or why not

no, it is not altered, no loss or gain

What is a genetic disorder

inherited disease caused by a mutation in a gene of by chromosmal defects