NEET : Multiple Choice questions: Codominance

1.When two alleles are present together than both allele express themselves independently under the genetic mechanism of
A. Codominance          

B. Dominance 

C. Incomplete dominance        D. Pleiotropy

Answer : A Explanation 

2. Match the list 

A . Hybrid does   1. Co domi-

     not resemble.     -nance

     With the 

     parent

B. Hybrid does    2. Domin-

     resemble.         -ance

     With one of  

     the  parent

  

C. Hybrid does     3. Incom-

     resemble.         -plete do

     With both           minance

     the  parent

       

        A       B       C

A.     1        2       3

B.     1        3       2

C.     3       2       1

D.     3       1        2

Answer : C Explanation 

3. Which one of the following pair is correctly matched.

A. Multiple allelism: Skin color

B. Codominance : blood group

C. Dominance : Snapdragon.

D. Incomplete dominance: Pisum

Answer : B Explanation 

4.The name of codominance predominantly has been given in terms of which blood group.
A. Blood group A          

B. Blood group B    

C. Blood group A B           

D. Blood group O   

Answer : C Explanation 

5. Consider the following statement and select the correct code : 
1. The plasma membrane  or surface of RBC has special type of sugar which is controlled by a gene I.          

2. Gene I has three allele IO, IA  and IB.  

3. IA and  IB  are completely dominant over IO.    

D. Allele  IO  does not produce any kind of sugar in blood of individual.

A. 1 2 and 3

B. 2 3 and 4

C. 1 and 4

D. 1 2 3 and 4

Answer : D Explanation

6. Gene I has three allele IO, IA  and IB to control the blood group but an individual recieve only two allele out of three due to 

A. Diploid in nature. 

B.Presence of sexual reproduction.

C. Mutation and variations 

D. Polyploidy and Aneuplody.

Answer: A Explanation

7. Gene I has three allele IO, IA  and IB and these alleles form how many different combination in human to determine the blood group.

A. Two     B. Four

C. Six.      D. Three

Answer : C Explanation

8. Three allele IO, IA  and IB form different combinations in human to determine the blood group on the basis of no present on 

A.Plasma membrane on WBC

B.Plasma membrane on RBC

C.Plasma composition in blood

D.Haemoglobin pigment in blood.

Answer : A Explanation

9. Multiple allelism refer to control the one trait by more than two allele like  

A. Starch synthesis in pea plant 

B. Human skin color

C.ABO Blood group system

D. Plasma protein 

Answer : C Explanation

10.  RBC does not have neither sugar A nor sugar B if person contain  

A. Blood group A

B. Blood group B

C. Blood group AB

D. Blood group O

Answer : D Explanation

11.  If father is heterozygous with blood group B and Mother is homozygous with blood group. Which of the following blood group is not present in their offspring.  

A. Blood group A

B. Blood group O

C. Blood group AB

D. All of the above.

Answer : D Explanation

12. A Child has blood group O and father has blood group A. What are possible genotype of their parents.

        Father        Mother

A.      IA IA          IB IO

B.      IA IO          IB IB

C.      IA IO          IB IO

D.      IA IA          IB IB

Answer : C Explanation