Chapter 2, Problem 20AQP

a.

Summary Introduction

To determine:

The two socks of a pair represents in the cell cycle.

Explanation of Solution

A pair of two socks is compared to the two chromatids of the chromosomes. The replicated chromosomes line up at the center of a cell undergoing division and like the socks in the riddle, the sister chromatids of each chromosome are pulled in opposite directions.

The blind men separate the socks with the same procedure as followed by the cells in the body to separte the chromatids in the chromosome.

b.

Summary Introduction

To determine:

The representation of two pairs of each color in a bag. If each blind man buys his own pairs of socks, but the clerk places all the pairs in one bag and there are two pairs of socks of each color in the bag.

Explanation of Solution

The different sets of chromosomes having sister chromatids. The pair of homologous chromosomes is similar to the situation in which the blind men have a pairs of socks of different colors. The homologous chromosomes represents the pair of socks of each color.

c.

Summary Introduction

To determine:

The thread that connects the two socks of a pair.

Explanation of Solution

There is a comparision between two socks of a pair and the two chromatids of a chromosome. The two chromosomes are attached by a protein known as cohesion similarly like the two socks are attached by a thread or string.

d.

Summary Introduction

To determine:

The molecular knife that cuts the thread which holds two socks of a pair together.

Explanation of Solution

During meosis, the chromatids which are attached by cohesion are get separated in anaphase II. This separation is catalysed by an enzyme known as separase. The separase enzyme act to separate the two chromatids which is similar to knife that seperates the socks in a pair.

e.

Summary Introduction

To determine:

The riddle that performs the same function as spindle microtubules.

Explanation of Solution

During the separation of chromatids in a chromosomes, the spindle fibers help in the separation. Simillary, like the blind men use their hand to pull apart the socks. So, the spindle fibers act on chromatids to separate them and the blind men uses their hands  to separate the socks.

f.

Summary Introduction

To determine:

The way in which the outcome relate to events in the cell cycle,if one man failed to grasp his sock of a particular pair.

Explanation of Solution

In this riddle, it is clear that one blind man fails to grasp a sock in a pair and all the pairs will go to the other man. This didtribution is unequal type of distribution.

This condition is similar with the condition, in which the two sister chromatids are not pulled in the opposite direction by the spindle fibers with the same force. This results into the unequal distribution of the chromatids. In this case, one of the daughter cell have more chromosomes as compared to the other one.

Conclusion

The chromosomes are considered as a pair of socks, which are bind by cohesion protein. The separation of socks is compared to the separation of chromosomes.