Multiple Alleles And Polygentic Traits

Question 1

Multiple alleles

Answer 1

Multiple alleles refers to a gene having more than two different versions (alleles), but since individuals can only inherit two versions, amongst individual there is genetic variation

Question 2

Example of genes with multiple alleles

Answer 2

Hair: different colors of hair

Blood type: different types of blood

Question 3

What alleles determine blood type

Answer 3

In humans, blood type is determined by 3 alleles (A B and O), but only two alleles are inherited.

Dominant- A and B (Codominance)
Recessive- O

A = AA or AO
B = BB or BO
AB = AB
O = OO

Question 4

Antigens

Answer 4

proteins on the cell membrane that
help the body recognize foreign
invaders, which alerts the immune system. Antigens are either positive or negative

Question 5

Antibodies

Answer 5

Once the antigens alert the immune system of foreign invaders, the immune produces blood proteins to bind to the antigen which the antigens tagged foreign invaders, and from there they eliminate the threat

Question 6

What is Rh factor

Answer 6

Rh factor is a type of antigen— a protein found on the surface of the blood cells.
* when Rh factor is present on cells, the blood type is positive
* when Rh factor is present on cells, the blood type is negative

Question 7

How is Rh factor inherited compared to blood type

Answer 7

Rh factor and blood type are completely separate from each other. Meaning they have a different set of alleles

Rh+ is dominant over Rh-, meaning someone who is Rh- is homozygous recessive. And someone with Rh+ is either homozygous or heterozygous dominant

That’s why the current blood type and Rh factor type are the same during medical emergencies like blood transfusion

Question 8

Blood types and Rh types

Answer 8

Type A (dominant) - AO or AA
Type B (dominant) - BO or BB
Type AB (Codominance) - AB
Type O (Recessive) - OO
Rh- (recessive) - Rh-/Rh-
Rh+ (dominant) - Rh+/Rh+ or Rh+/Rh-

Question 9

Rabbits fur coat color

Answer 9

Chinchilla is incompletely dominant over Himalayan and albino

Himalayan is completely dominant over albino

Question 10

Polygenic traits

Answer 10

Are genes that are produced from the interactions of many different alleles from different genes

Question 11

Examples of polygenic traits

Answer 11

Traits that are determined by many different genes

Hair (124 genes)
Height (50 genes)
Skin (150 genes)
Eye color (16 genes): The main gene responsible for eye color lays on chromosome 15