Problem 2 - Biology Concepts and Applications

Question

A duplicated chromosome has ___ chromatid(s). a. one c. three b. two d. four

Step-by-Step Solution

Answer

b. two

Step 1: Understand Chromosome Duplication

When a chromosome is duplicated, it consists of two identical copies referred to as sister chromatids. These chromatids are eventually separated during cell division processes such as mitosis or meiosis.

Step 2: Analyze the Answer Choices

Look at the provided answer choices: a. one, b. two, c. three, d. four. We need to find the option that corresponds to the number of chromatids in a duplicated chromosome.

Step 3: Match Duplicate Chromosome to Chromatids

A duplicated chromosome specifically refers to two sister chromatids held together at a region called the centromere. Therefore, a duplicated chromosome has two chromatids.

Step 4: Select the Correct Answer

Based on our understanding, the correct answer is b. two, as this corresponds to the number of chromatids in a duplicated chromosome.

Key Concepts

Understanding Sister Chromatids

When a cell prepares to divide, it goes through a process called replication where each chromosome duplicates. The duplicates it creates are called sister chromatids. These chromatids are identical copies of the original chromosome. They carry the same genetic information because they originate from the same DNA molecule.
In the context of cell division, sister chromatids play a crucial role. They ensure that each new cell receives the same genetic information. This is vital for maintaining consistency across cells, particularly in growth and repair processes.

• Sister chromatids are joined together before they move to new cells.
• They separate eventually during cell division, delivering identical genetic information to each cell.

Understanding sister chromatids helps us comprehend how genetic information is conserved through cell generations. Their role emphasizes the importance of accurate DNA replication prior to cell division.

The Process of Cell Division

Cell division is an essential process that allows organisms to grow and reproduce. It consists of two major types: mitosis and meiosis. Each serves a specific function, with mitosis playing a role in growth and repair, while meiosis is key in producing reproductive cells.
During cell division, duplicated chromosomes, consisting of sister chromatids, are distributed to two new cells. This ensures each new cell contains the same genetic material. Here's a brief overview:

• Mitosis: Involves one division event, resulting in two identical cells.
• Meiosis: Involves two division events, producing four genetically diverse cells.

Each type of cell division has its unique characteristics and purposes, but the process of distributing sister chromatids remains a common and crucial step. It ensures genetic continuity and variation where necessary.

Role of the Centromere

The centromere is a region on a chromosome where the two sister chromatids are held together. This region is incredibly important because it is the attachment site for spindle fibers during cell division. These fibers are responsible for pulling sister chromatids apart, ensuring they move to opposite ends of the cell.
During the division process, the centromere ensures that each new cell receives one copy of each chromosome.

• Tightly holds the sister chromatids together until they are ready to separate.
• Acts as a point of attachment for spindle fibers, facilitating chromatid movement.

The centromere's role highlights the intricate coordination within cells to maintain genetic integrity. This ensures an accurate and equal split of genetic material during every cell division.