Q: Which genotype(s) result in type A blood in the ABO blood group system?

$$I^A I^A$$ \, \text{and} \, I^A I^O$

Question 1

In incomplete dominance, what phenotype is observed in the heterozygote?

Accepted Answer

A phenotype that is an intermediate of the two homozygotes

Question 2

A cross between a red-flowered snapdragon (R1R1) and a white-flowered snapdragon (R2R2) produces pink-flowered offspring. What is the genotype of the pink-flowered offspring?

Accepted Answer

$$R_1R_2$$

Question 3

Which of the following best describes codominance?

Accepted Answer

Both alleles are fully expressed in the heterozygote

Question 4

If a person with genotype $$I^A I^B$$ has children with a person with genotype $$I^O I^O$$, what are the possible blood types of their children?

Accepted Answer

Type A and Type B

Question 5

A gene for the MN blood group has codominant alleles M and N. If both children in a family are of blood type MN, what must be true about the parents?

Accepted Answer

Each parent is either M or MN

Question 6

How many different alleles exist for the ABO blood group system, and how many different blood types result from these alleles?

Accepted Answer

3 alleles, 4 blood types

Question 7

Which of the following is an example of codominance in humans?

Accepted Answer

AB blood type

Question 8

If you cross two pink snapdragons ($$R_1R_2 x$$ $$R_1R_2$$), what is the expected phenotypic ratio of their offspring?

Accepted Answer

1 red : 2 pink : 1 white

Question 9

A person with genotype $$I^A I^O$$ has children with a person with genotype $$I^B I^O. $$What is the probability that their child will have type O blood?

Accepted Answer

$$\frac{1}{4}$$

Question 10

Which of the following statements about incomplete dominance and codominance is correct?

Accepted Answer

Incomplete dominance results in a blended phenotype, while codominance results in both traits being fully expressed.

Question 11

If a person with type AB blood receives a transfusion from a type O donor, what will happen?

Accepted Answer

The transfusion will be successful because type O blood has no A or B antigens.

Question 12

Which genotype(s) result in type A blood in the ABO blood group system?

Accepted Answer

$$I^A I^A$$ \, 	ext{and} \, I^A I^O$

Question 13

A child has type O blood. Which of the following parental genotype combinations could produce this child?

Accepted Answer

Both parents are $$I^O I^O or $$both are $$I^A I^O$$ and $$I^B I^O$$

Question 14

Which of the following best explains why a person with genotype $$I^A I^B$$ expresses both A and B antigens on their red blood cells?

Accepted Answer

The $$I^A$$ and $$I^B$$ alleles are codominant

Question 15

If a person with genotype $$I^A I^B ($$type AB) has children with a person with genotype $$I^O I^O ($$type O), what is the probability that their child will have type B blood?

Accepted Answer

$$\frac{1}{2}$$

Question 16

Which of the following crosses would produce only pink-flowered snapdragons?

Accepted Answer

$$R_1R_1$$ 	imes R_2R_2$

Question 17

A blood sample from a person who is heterozygous at the MN blood group locus is tested. What will be observed?

Accepted Answer

Both M and N shaped red blood cells will be seen

Question 18

Which of the following is NOT a possible genotype for a person with type B blood?

Accepted Answer

$$I^A I^O$$

Question 19

If a red-flowered snapdragon ($$R_1R_1) is $$crossed with a pink-flowered snapdragon ($$R_1R_2$$), what percentage of the offspring are expected to be pink?

Accepted Answer

50\%

Question 20

Which of the following best describes the difference between incomplete dominance and codominance?

Accepted Answer

Incomplete dominance results in a blended phenotype, while codominance results in both phenotypes being expressed side by side.

Incomplete Dominance and Codominance in Genetics

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