BIOLOGY NOTES

 

Blending hypothesis

The hereditary material of the parents will give a combined effect in the offspring

 

Particulate hypothesis

Parents pass separate and distinct factors to their offspring. Those factors are responsible for the inherited traits.

 

Genetics

The scientific study of heredity

 

Gregor Mendel


Father of Genetics. Austrian Monk. Late 1800s. Background in Biology, Math, and Physics. Bred Pea Plants. "Factors" are "genes"

 

Advantages of using Pea Plants

-Enclosed flower structure: Pollen cannot escape.
-Self-fertilize: Can cross fertilize by hand.
-Grow and reproduce quickly: 90 day life cycle.
-Generally only 2 variations of each trait

 

 

Purebreds


Have the same parents. They only produce one form of a trait. (Both purple parents and the only possible result is a purple plant)

 

 

Hybrids


A purebred mixed with a different purebred

 

 

Trait

A genetic characteristic. Can be passed from parent to offspring.

 

 

Mendal's experiment


Important features:
Know generation names (parental, F1, F2), 100% breakdown, the benefits of using pea plants

 

 

Factors

Mendal said parents transfer factors.

 

 

Homozygous


Same alleles

 

 

Heterozygous


Different alleles

 

 

Alleles


Different forms of a gene

 

 

Genotypes


Describes the GENETIC makeup.

 

 

Phenotype


Describes the APPEARANCE or DESCRIPTION. (Think PHYSICAL makeup of the plant)

Dominant Allele


If present, it will express the trait and DOMINATE the other trait.

Recessive Allele


It will only express in the absence of a dominant allele.