Intro to Genetics

By Justin Ehrenpreis

Genetics

The Branch of Biology that deals with patterns of inheritance

Heredity

Parents genetic information to offspring through gametes

Gregor Mendel

Austrian monk

Started science of genetics

Experimenting with pea plants

Mendel came up with….

Principles of Dominance,

Segregation

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Independent Assortment

Traits are….

inherited

Mendel’s hereditary factors called……

genes

Location………

locus

Gene is…..

A hereditary unit consisting of a sequence of DNA that tells specific location

T.H. Morgan

Carried out breeding experiments (crosses)

With fruit flies (Drosophila)

Two alternate genes……

Control each trait is called….

alleles

Homologous chromosomes

Matching chromosomes

Genotype

Genes presented in DNA of an organism

SHOWS

Pairs of letters

Genotypes

2 letters

genotype

Phenotype

Trait physically shows up in the organism

MADE

TT=

HOMOZYGOUS

=PURE

Tt =

Heterozygous

=hybrid

tt=

Homozygous

=Pure

Test cross

Introduced by Mendel in order to determine if an individual exhibit dominant trait

He crossed a homozygous recessive….

Recessive means lowercase

contrasting

different

Hybrid for trait has only….

Dominant trait in the phenotype

TT

Homozygous DOMINANT

Or pure tall

Tt

Heterozygous or hybrid = TALL

tt

Homozygous RECESSIVE or pure short

Two alleles responsible for

Trait separate from each other.

Alleles recombined at…..

FERTILIZATION

Producing genotype for traits of offspring

Hybrid tall is

Tt

25% Tall25% small50% tall

Shape, hair, and color has no impact on one another

Incomplete dominance

BLENDING

codominance

Together

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