Lesson 6: Incomplete And Codominance

Question 1

What is COMPLETE DOMINANCE?

Answer 1

One trait completely covers the other (like a red flower hiding a white flower).

Detailed Example : In pea plants, when a tall plant (TT) is crossed with a short plant (tt), all offspring (Tt) are tall. This is complete dominance because the tall trait completely covers the short trait.

Question 2

What is INCOMPLETE DOMINANCE?

Answer 2

Both alleles have an influence, producing a third phenotype. (Both alleles mix together to create a new phenotype)

Example: When a red flower (RR) is crossed with a white flower (WW), the offspring (RW) are pink. This is incomplete dominance because the colors mix to create a new blend.

Question 3

What is CODOMINANCE?

Answer 3

Both alleles are expressed equally but not mixed.

Detailed Example: In snapdragons, when a red flower (RR) is crossed with a white flower (WW), the offspring (RW) have both red and white spots. This shows codominance because both colors appear together.

Question 4

What are the possible phenotypes for blood types?

Answer 4

Type A, Type B, Type AB, and Type O.

Genotypes: IAIA or IAi for Type A, IBIB or IBi for Type B, IAIB for Type AB, and ii for Type O.

Question 5

On which chromosome is the human ABO gene located?

Answer 5

The human ABO gene is on chromosome 9.

Question 6

How many copies of chromosome 9 do humans have?

Answer 6

Everyone has two copies of chromosome 9.

Question 7

What are the alleles for blood type?

Answer 7

The blood type gene has three different alleles: I^A, I^B, and i.

Question 8

What is the dominant allele in blood type?

Answer 8

The ‘A’ allele is dominant and so is the ‘B’ allele.

Question 9

What is the recessive allele in blood type?

Answer 9

The ‘O’ allele is recessive.

Question 10

What blood type results from the alleles I^A and I^B?

Answer 10

The blood type will be AB.

Question 11

What is an antigen?

Answer 11

An antigen is a protein that sits on the surface of your red blood cells.

Question 12

What antigens are present in type A blood?

Answer 12

If you have the A antigen, you have type A blood.

Question 13

What antigens are present in type B blood?

Answer 13

If you have the B antigen, you have type B blood.

Question 14

What antibodies are present in group A blood?

Answer 14

Group A has anti-B antibodies.

Question 15

What antibodies are present in group B blood?

Answer 15

Group B has anti-A antibodies.

Question 16

What antibodies are present in group AB blood?

Answer 16

Group AB has no antibodies.

Question 17

What antibodies are present in group O blood?

Answer 17

Group O has anti-A and anti-B antibodies.

Question 18

What is the blood type for a child if Mom has alleles I^A and Dad has alleles I^B?

Answer 18

The blood type for their child would be AB.

Question 19

What is the blood type for the combination A + A?

Answer 19

The blood type is A.

Question 20

What is the blood type for the combination A + O?

Answer 20

The blood type is A.

Question 21

What is the blood type for the combination A + B?

Answer 21

The blood type is AB.

Question 22

What is the blood type for the combination B + B?

Answer 22

The blood type is B.

Question 23

What is the blood type for the combination O + O?

Answer 23

The blood type is O.

Question 24

Blood plasma is packed with proteins called

Answer 24

Antibodies

Question 25

The body produces a wide variety of antibodies that will..

Answer 25

recognize and attack foreign molecules

Question 26

Blood antibodies are..

Answer 26

proteins that circulate in the blood and help the body’s immune system fight off foreign substances, such as bacteria and viruses

Question 27

If the donors blood cells have antigens that are different from those of the recipient,

Answer 27

the antibodies in the recipients blood recognize the donor blood as foreign, which triggers an immune system response resulting in blood clots

Question 28

What is an example of Codominance in blood?

Answer 28

An example of codominance in blood is AB blood type, where both A and B alleles are fully expressed, resulting in blood cells with both A and B antigens.