Polygenic Inheritance – Check Test

 

1.         Which of the following is an example of discontinuous variation?

            A    Height in humans

            B    Tail length in mice

            C    Tongue rolling in humans

            D    Weight of pigs

 

2.         A characteristic which shows a range of differences from

            one extreme to another is said to show

            A    polygenic variation.

            B    single – gene inheritance.

            C    discontinuous variation.

            D    continuous variation.

 

3.         Single – gene inheritance is where

            A    characteristics are controlled by one gene.

            B    characteristics are controlled by more than one gene.

            C    one gene is not enough to control a characteristic.

            D    many genes are involved in controlling a characteristic.

 

4.         If a characteristic is controlled by the alleles of more than

            one gene the characteristic is said to be

            A    polygenic.

            B    continuous.

            C    discontinuous.

            D    codominant.

 

5.         Compared to a characteristic controlled by two genes, a

            characteristic controlled by five genes will have

            A    the same number of genotypes.

            B    more different phenotypes.

            C    fewer different genotypes.

            D    fewer different phenotypes.

 

6.         A punnett square is drawn to represent the genotypes in the offspring

            of a cross between two maize plants which each have genotypes for

            medium – red kernels (R1 r1 R2 r2).

                        R1r1R2r2           x              R1r1R2r2

                       

                       

M/F

R1R2

R1r2

r1R2

r1r2

R1R2

 

 

 

 

R1r2

 

 

Y

 

r1R2

 

X

 

 

r1r2

 

 

 

 

 

            Which genotypes should appear at X and Y in the square?

 

           

 

X

Y

A

R1r1R2r2

R1r1R2r2

B

R1R1R2r2

R1R1r2r2

C

R1r1R2R2

R1r1R2R2

D

r1r1R2r2

r1r1R2R2

 

7.         Which of the following is NOT an example of polygenic inheritance?

            A    Height in humans

            B    Tail length in mice

            C    Hand span in humans

            D    Coat colour in horses

 

8.         Which line in the table is correct when referring to single – gene inheritance?

 

           

 

Number of genes controlling a characteristic

Type of variation

A

1

continuous

B

2

continuous

C

1

discontinuous

D

2

discontinuous