Lecture 1

Question 1

Which statement does not describe a classical assumption most scientists and the general public had before the experiments of Kolreuter (1760s), T.A. Knight (1832) and Mendel?

Answer 1

1. You can take 2 different species w/ similar body parts and breed them
2. Species don’t change overtime (physically, genetically, etc).
3. If you have something physically happen to you and then you have a child, the child would also have those things (you dye your hair, you’re an amputee, etc).

Question 2

What were the findings of Josef Kolreuter (1760s) regarding patterns of inheritance?

Answer 2

Josef = Tobacco + Cross

Question 3

What were the findings of T.A. Knight (1832) regarding patterns of inheritance?

Answer 3

TA = Pea + Self

Question 4

What is the definition of true-breeding?

Answer 4

Offspring produced from self fertilization remains uniform for a period of time

Question 5

Mendel, through his pea experiments, came up with the terms segregation, character, and traits. How are these words related to one another?

Answer 5

Segregation = When some offspring exhibit alternative forms of a character compared to the parents
Characters = Physical representation of your genetics (phenotype)
Traits = Different form of character based on genetics

Question 6

Male and female sexual organs are enclosed within a pea flower which Mendel used. He would self-pollinate and cross-pollinate to obtain his results. What is the difference between self-pollination and cross-pollination?

Answer 6

Self = Sex organs create a zygote from the same plant
Cross = Same species but different individuals. Go and take sperm from 1 individual flower and put into another individual flower

Question 7

Which statement describes the results of Mendel’s experiments (i.e. what did we learn from them being completed)?

Answer 7

F2 Generation had a 3:1 phenotype, F1 generation it had a 4:0 phenotype because there were no white so it was 100% only purple (We learned there could be disguised ratios, where the traits can be hidden).

Question 8

What is the difference between a dominant and recessive trait?

Answer 8

Dominant = Always show up in Mendilian genetics
Recessive = Only show up when dominant don’t

Question 9

What is the (a) genotypic and (b) phenotypic ratio of the offspring of a monohybrid cross of a heterozygous male and heterozygous female plant? H = tall and h = short

Answer 9

H h
H HH Hh
h Hh hh
Genotype = 1 HH, 2 Hh, 1 hh (3:1 ratio)
Phenotype = Tall

Question 10

What does it mean that Mendel discovered a “disguised ratio?”

Answer 10

Disguised ratio = masked by heterozygotes