Question

How many sister chromatids are seen in the metaphase for a single chromosome? How different are these structures from the interphase chromatin?

Short answer

Answer: In a single chromosome during metaphase, there are two sister chromatids. The main difference between metaphase chromosome structure and interphase chromatin is the level of chromatin condensation and organization; metaphase chromosomes are highly condensed and organized for proper segregation during cell division, while interphase chromatin is loosely coiled and dispersed, allowing gene transcription to occur.

Step-by-step solution

1. Understanding sister chromatids and metaphase

During mitosis, the process of cell division, chromosomes are first duplicated and then separated into two identical sets, ensuring the daughter cells receive the correct number of chromosomes. At the beginning of mitosis, each chromosome is made of two identical structures called sister chromatids, held together at a region known as the centromere. During metaphase, one of the stages of mitosis, the sister chromatids line up at the equator of the cell, preparing for separation in the next stage, anaphase.

2. Determining the number of sister chromatids in metaphase for a single chromosome

In metaphase, a single chromosome consists of two identical sister chromatids. So, for a single chromosome in metaphase, there are two sister chromatids.

3. Understanding interphase chromatin

Interphase is the stage of the cell cycle when the cell is not actively dividing but is preparing for division by replicating its DNA and other cellular components. This is when the genetic material is in the form of loosely coiled chromatin. The chromatin consists of DNA and its associated proteins, mainly histones.

4. Comparing metaphase chromosome structure to interphase chromatin

During interphase, the chromosomes are uncondensed and in the form of dispersed chromatin, which allows for the transcription of genes to produce RNA and proteins as needed by the cell. In contrast, during metaphase, the chromosomes become highly condensed and organized, with the chromatin tightly coiled around the histone proteins. This compact structure is necessary for the chromosomes to be easily segregated during cell division, ensuring each daughter cell receives an identical set of chromosomes. The main difference between these structures is the level of chromatin condensation and organization, which varies depending on the specific stage of the cell cycle.