Lesson 4, Unit 2: A typical Dominance

Question 1

Test Cross

Answer 1

a genetic cross between a homozygous recessive individual and a corresponding suspected heterozygote to determine the genotype of the latter

Question 2

Purebred

Answer 2

bred from parents of the same breed or variety

Question 3

Hybrid

Answer 3

In biology a hybrid, also known as cross breed, is the result of mixing, through sexual reproduction, two animals or plants of different breeds, varieties, species or genera

Question 4

Incomeplete Dominance

Answer 4

When the two traits from pure strains appeared to blend in the hybrids, 
they referred to the phenomenon as “incomplete dominance”. Conventionally, we use lower case letters with superscripts for 
incompletely dominant alleles.

Question 5

Complete Dominance

Answer 5

A kind of dominance wherein the dominant allele completely masks the effect of the recessive allele in heterozygous condition

Question 6

Codominance

Answer 6

With codominance, a cross between organisms with two different phenotypes produces offspring with a third phenotype in which both of the parental traits appear together

Examples:

Cattle can be red (RR = all red hairs), white (WW = all white hairs), or roan (RW 
= red & white hairs together).

Human blood type AB, in which two types of protein (“A” & “B”) appear together on the surface of blood cells.