Chapter 5

Question 1

Who worked with garden peas?

Answer 1

Gregor Mendel

Question 2

What did the peas explain?

Answer 2

explained the mechanism of gene inheritance in plants and provided a basis for understanding heredity in general

Question 3

Medels First experiment

Answer 3

when Mendel crossed pure-breeding tall plants with pure-breeding dwarf plants (P1 or parental generation), the next (F1 or filial) generation was always tall
the tall trait dominated, regardless of whether the trait came from the pollen (“father”) or the egg (“mother”) and he found the same to be true for the other 6 characteristics
Mendel decided that “factors” control the traits of a plant (genes) and that there are alternate forms of genes (alleles)
the traits that were expressed most often were considered dominant and those expressed less frequently were recessive
when gametes are formed from the F1 (hybrid) generation and then recombined in the F2 generation, the recessive trait reappears because the probability exists for a combination that does not include the dominant allele and can therefore express the recessive trait

Question 4

Allele

Answer 4

a variant form of a gene

Question 5

homozygous

Answer 5

having two identical alleles of a particular gene or genes.

Question 6

heterozygous

Answer 6

having two different alleles of a particular gene or genes.

Question 7

4 blood types

Answer 7

IAIA, IAi = type A
IBIB, IBi = type B
IAIB – type AB
ii = type O