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Flashcards in Lecture 11 Deck (14):
1

Gregor Mendel

Pea plant breeding experiments
✴ Varied in easily described characters
- Color
- Pea shape
- Pea color
No knowledge of DNA
Experiments repeated, results repeated
• Inheritance particulate!
- characters are not diluted

2

What inheritance pattern did Mendel come up with?
✴ Blending or particulate?

particulate

3

Fundamental laws resulting from Mendel

1. Law of Segregation
2. Law of Independent Assortment

4

Law of Segregation

during the production of gametes the two copies of each hereditary factor segregate so that offspring acquire one factor from each parent

5

Law of Independent Assortment

Genes for different traits can segregate independently
during the formation of gametes

6

Genotype

Individual’s genetic composition

7

Homozygote

Two identical alleles

8

Heterozygote

Two different alleles

9

Phenotype

Visible characteristics of an individual
• Interaction of genotype & environment

10

Particulate inheritance

genes determine the phenotypes that are passed on from parents to offspring across generations.

11

(Physical) Linkage

• A violation of independent assortment
• Genes are inherited together more often than
expected because they are on the same
chromosome

12

What is crossing over?

exchange of genetic information between
homologous chromosomes

13

When does crossing over occur?

Prophase I

14

What effect does crossing over have on linked genes?

unlinks alleles along a
chromosome