Question

1. The correct sequence of stages of mitosis is ______.

      
A. anaphase, interphase, prophase, metaphase, telophase

       
B. prophase, metaphase, anaphase, telophase

       
C. interphase, prophase, metaphase, anaphase, telophase

       
D. telophase, prophase, interphase, anaphase, metaphase

2. Labrador retrievers come in several colors: brown, black, or yellow. In a cross of a black female with a brown male, results can be either all black puppies, 1/2 black to 1/2 brown puppies, or 3/4 black to 1/4 yellow puppies. What to these results indicate?

      
A. Yellow is dominant to black.

       
B. Black is dominant to brown and to yellow.

       
C. Brown is dominant to black.

       
D. There is incomplete dominance.

       
E. There must be epistasis involved.

3. Drosophila (fruit flies) normally have long wings (+), but mutations in two different genes can result in bent wings (bt) or vestigial wings (vg). If a homozygous bent wing fly is mated with a homozygous vestigial wing fly, which of the following offspring would you expect?

      
A. all +bt +vg heterozygotes (phenotype: 100% long wings)

       
B. 1/2 bent and 1/2 vestigial flies (phenotype: 50% bent wings, 50% vestigial wings)

       
C. all homozygous + flies (phenotype: 100% long wings)

       
D. 1/2 bent and vestigial to 1/2 normal (phenotype: 50% bent wings and vestigial wings, 50% long wings)

       
E. 3/4 bent to 1/4 vestigial ratio (phenotype: 75% bent wings, 25% vestigial wings)

4. The spines of cacti may be sharp or dull. Gene S controls the sharpness of spines in a type of cactus. Cactuses with the dominant allele, S, have sharp spines, whereas homozygous recessive ss cactuses have dull spines. At the same time, a second gene, N, determines whether cactuses have spines or not. Homozygous recessive nn cactuses lack any spines at all. A cross between a true-breeding sharp-spined cactus and a spineless cactus would produce

      
A. 25% sharp-spined, 50% dull-spined, 25% spineless progeny.

       
B. all sharp-spined progeny.

       
C. It is impossible to determine the phenotypes of the progeny.

       
D. all spineless progeny.

       
E. 50% sharp-spined, 50% dull-spined progeny.

5. The heterogametic sex determines the sex of the progeny.

A. True
B. False

Answer 1

Ans. 1- B option is correct. Prophase, Metaphase, Anaphase and Telophase.

In the first stage of mitosis i.e, prophase stage the chromosomes gets condensed and nuclear envelope is not apparent.

In Metaphase stage, thick coiled chromosomes each with two chromatids, are lined up on the Metaphase plate.

In Anaphse stage, the chromatids of each chromosome have separated and are moving towards the poles.

In Telophase stage, the chromosomes are at the poles and are becoming more diffuse. The nuclear envelope is reforming.