Can someone please tell me when a chromosome is a chromosome and when it is called a chromatid.

For ex/ after anaphase the chromatids are now each called a chromosome,etc

http://en.wikipedia.org/wiki/Chromatid

see the picture on the right, and read the first paragaraph

Chromosome is always a chromosome through out mitosis.chromosome and chromatids are two different things.Each chromosome is made of two strands and these strands are called chromatid.Chromatids of same chromosome are called sister chromatids and they are joined at a point called centromere.

1 during prophase chromosome(consisting of two chromatids) thicken

2 during metaphase chromosome(consisting of two chromatids) lie at equator

3 during anaphase two chromatids of each chromosome separate.

4 during telophase chromatid develop in to new chromosomes.

Certainly! Understanding the terminology surrounding chromosomes and chromatids can be a bit tricky, but I'll explain it to you.

During cell division, specifically in a process called mitosis, the DNA in a cell's nucleus replicates and forms identical copies known as sister chromatids. Each chromatid is a single DNA molecule, but they are still attached to each other at a region called the centromere.

Now, during anaphase, the sister chromatids separate and move towards opposite ends of the dividing cell. At this point, while they are still connected at the centromere, they are referred to as chromosomes. So, after anaphase, each sister chromatid is now called a chromosome.

To summarize:

- Before replication: Chromosome
- After replication: Sister chromatids (attached at the centromere)
- After anaphase: Individual chromosomes (sister chromatids separate)

It's important to note that chromatids are only called chromosomes after they separate during anaphase. During other stages of the cell cycle or mitosis, they are referred to as sister chromatids.