Chromosomes form after DNA replicates; prior to replication, DNA exists as chromatin. Chromosomes contain genes, which code for proteins. Human cells normally have 46 chromosomes, made up of two sets of chromosomes, one set inherited from each parent.
Why do chromosomes form in prophase?
During prophase, the complex of DNA and proteins contained in the nucleus, known as chromatin, condenses. The chromatin coils and becomes increasingly compact, resulting in the formation of visible chromosomes. Chromosomes are made of a single piece of DNA that is highly organized.
What is the main purpose of chromosomes?
Chromosomes are thread-like structures in which DNA is tightly packaged within the nucleus. DNA is coiled around proteins called histones, which provide the structural support. Chromosomes help ensure that DNA is replicated and distributed appropriately during cell division.
What are the 4 types of chromosomes?
On the basis of the location of the centromere, chromosomes are classified into four types: metacentric, submetacentric, acrocentric, and telocentric.