Genetics

Genetics is the branch of science that studies in heredity and variations.

Gregor Johann Mendel is the "Father of Classical Genetics." HE is an augustinian monk. He studied BSE Physics. He was in charge of taking care of garden peas.

HE chose garden peas as his specimen because:

Several generations over a short period of time

short life span

low maintenance

contrasting characteristics

1.) color of seed(yellow, green)

2.) shape of seed(round, wrinkled)

3.) pod color(green, yelow)

4.) pod shape(inflated, constricted)

5.) flower position(axial, terminal)

6.) flower color(purple, white)

7.) plant height(tall, short)

MENDEL'S EXPERIMENTS

1.) He created a pureline of each trait through self pollination.

2.) He created a hybrid by cross pollination.

3.) He found out the characteristics are not affected byunit determiners.

Dominant trait- one being expressed

Recessive trat- not expressed

Law of Dominance- When alleles for 2 contrasting characteristics are present in the same individual, the dominant trait is expressed but the recessive trait is not.

Law of Segregation- 2 genes for a character separate during the formation of the gametes.

Law of Independent assortment- Genes for different characteristics are transmitted independently from one generation to the next.

NON-MENDELIAN GENETICS

Incomplete dominance- Crossing of homozygous dominant and recessive trait that results into a heterozygote having an intermediate trait.

Example:

A white flower cross breeding with a red flower will result to pink flower.

Codominance- Crossing of 2 homozygous dominant and recessive trait that results into a heterozygote having a 50:50 appearance of the parents.

Example:

A red cattle cross breed with a white cattle will result to a roan cattle.

Multiple Alleles- This means that more than 2 alleles of a gene affect a certain trait. A combinationof any 2 allels may be present in the individual.

Example:

Blood Type

It is a human characteristic. It is also inheritable. A person should be A, B AB, or O.

NiCo CaStIlLo