Genetics and Inheritance

Gregor Mendel - who was he? what was his job? what ‘nickname’ has he been given and why?

• Austrian Monk/biologist known as “the father of modern genetics”

• Worked in his church garden leading him to discover pea plants that were feasible to use/reproduced quickly

• discovered how traits were passed from parents to offspring

What were Mendel’s Laws of Inheritance?

• Law of Independent Assortment - alleles for different genes separate into gametes during meiosis independently of one another, the inheritance of other traits do not affect each other

• Law of Segregation - pairs of alleles for a trait segregate so that each gamete only gets one. Its offspring inherit one allele from each parent.

• Law of Dominance - genotypes are characterized by dominance and recessiveness. dominant alleles dominate while recessive alleles can be masked and only expressed when there’s two of them

Monohybrid Cross

Two similar traits that are crossed together (4 boxes)

Trait

An inherited/genetically determined characteristic

Allele

Alternative forms of a gene that are found the same place on a chromosome that codes for traits

How many chromosomes are in a typical human cell?

46

How many chromosomes are in a typical human gamete?

23

How many autosome pairs are in a typical cell?

22

How many sex chromosome pairs are in a typical cell?

1