Inheritance

Question 1

Core Concepts of Mendelian Inheritance

Answer 1

• principle of segregation: members of a gene pair separate equally into gametes
• principle of independent assortment: different gene pairs segregate independently

Question 2

Early transmission genetics

Answer 2

• Hippocrates: each part of the body produced a substance that collects in the reproductive organs that determines inherited traits
• Aristotle: potential to produce traits

Question 3

Blending Inheritance

Answer 3

• many people in the 19th century believed in blending
• traits will be a combination or resemble that of parents (blue flower + red flower = purple flower)
• suggests variation will be lost over time

Question 4

Modern Transmission Genetics (Mendel)

Answer 4

• Gregor Mendel found it is genes not traits that are transmitted
• he crossed pea plants by interbreeding (hybridization)
• focused on seven traits
• crossed true breeding strains (P1 - parent generation), trait appearing in F2 (progeny) is dominant
• the F2 gen (F1 self fertilization) the recessive trait appeared

Question 5

test crosses

Answer 5

• by crossing F1 progeny with true-breeding recessive you can learn the genotype of the unknown parent
• Aa:aa = 1:1
• Aa:Aa=1:1

Question 6

Incomplete Dominance

Answer 6

-phenotype of the heterozygous genotype is intermediate between the homozygous
- use superscripts as there is no dominant
- 1:2:1

Question 7

Addition and Multiplication Rules

Answer 7

Addition: when the outcomes cannot occur simultaneously, add probabilities
Multiplication: can occur simultaneously, multiply

Question 8

Independent assortment

Answer 8

• the segregation of one set of alleles of a gene pair is independent of the segregation of another set
• cross of two plants homozygous for two traits - 9:3:3:1