Chapter 11 Genetics (Silva 1406)

Genetics

Branch of Biology that studies the passing of traits from parents to offspring

Gregor Mendel

Father of Genetics

First person to successful predict the inheritance of traits

Famous for his Pea experiments

Chromosome

Condensed DNA that carry genetic info in the form of genes

Genes

A segment of DNA that carries the info to a certain trait

Allele

Different form of a gene

Dominant

Trait that will always appear when present in a gene

Recessive

Trait that will only appear if there is no dominant allele to cover it

Gene Locus

The specific location of a gene on a chromosome

Homozygous (AA, aa)

Same type of allele

Heterozygous (Aa)

Different type of allele

F1

First Filial Generation

Punnett Square

Diagram used to predict the possible genotypes of the offspring of a couple

Genotype

The combination of alleles for a trait

Ex- AA, Aa., aa

Phenotype

The physical/seen traits of an organism

Ex- Brown Eyes, Red Hair, Ugly

Monohybrid Cross (Aa x Aa)

A cross between 2 parents involving only ONE trait

Dihybrid Cross (AaBb x AaBb)

A cross between 2 parents involving TWO traits

Genotype Ratio

The amount of times every type of genotype appears in a cross

Ex-

Aa x Aa = 1:2:1

Phenotype Ratio

The amount of times every type of phenotype appears in a cross

Ex-

Aa x Aa = 3:1

Incomplete Dominance

When both the dominant and recessive alleles in a heterozygous individual are partially expressed, resulting in an intermediate phenotype

Ex-

Black x White = Grey

Co-Dominance

When both alleles in a heterozygous individual are expressed

Ex-

Blood Type AB

Black x White = Black with White Spots