Chromosomes Overview

What is the main function of the centromere in chromosomes?

How many pairs of chromosomes do humans have?

What is a chromatid?

What composes chromatin?

What is the role of telomeres in chromosomes?

What are chromomeres?

What does the matrix (pellicle) surrounding each chromosome consist of?

What is the function of secondary constriction in chromosomes?

What is a chromonema?

Chromosomes

Thread-like structures in the nucleus containing DNA.
Found in both plant and animal cells.
Humans have 23 pairs of chromosomes.
Centromere or Kinetochore: The primary constriction point at the center of a chromosome.
- It's where chromatids or spindle fibers attach.
- Responsible for chromosome movement during anaphase.
Chromatids: Two identical halves of a chromosome formed during cell division.
- Joined at the centromere.
- Separate at anaphase.
- Each contains DNA.
Chromatin: A complex of DNA and proteins that forms chromosomes.
- Includes DNA, RNA, and proteins.
Secondary Constriction: Usually present for the organization of the nucleolus.
Telomere: The end region of each chromosome arm.
Chromonema: Thread-like, coiled structure along which chromomeres are arranged.
- Controls the size of the chromosome.
- Site for genes.
Chromomeres: Bead-like structures arranged in a row along the chromonema.
- Carry genes during cell division.
Matrix (Pellicle): Membrane surrounding each chromosome.
- Contains a jelly-like substance (matrix).
- Composed of non-genetic material.

This quiz explores the structure and function of chromosomes, including their components such as centromeres, chromatids, and chromatin. Understand how these thread-like structures play a crucial role in cell division and genetic organization. Perfect for students studying cell biology.