Name: Hormones and the Life Cycles of Insects and Frogs
Uploaded: 2019-07-19
Duration: 6 min 46 s
Description: Let's learn about the stages in the life cycle of frogs and insects and the role of thyroxine and insect hormones in metamorphosis.

Question

Write about different types of chromosomes, based on the position of the centromere.

Accepted Answer

Chromosomes are structures in cells that contain deoxyribonucleic acid (DNA). DNA is a genetic material that contains the hereditary information of an organism. Chromatid, centromere, short arm (p), and long arm (q) are the parts of chromosomes. Chromosomes are formed of chromatin. Chromatin is a fibrous genetic material produced by the DNA-histone complex. Each chromosome is formed of tightly coiled DNA around proteins termed histones that maintain their composition. Humans possess $46$ chromosomes organized in $23$ pairs.

Based on the location of the centromere, chromosomes are divided into metacentric, submetacentric, acrocentric, and telocentric chromosomes.

Metacentric: A type of chromosome in which the centromere is positioned at the middle of the chromosome. Therefore, the two arms are almost identical.

Sub-metacentric: A type of chromosome in which the centromere is positioned near the middle is known as a submetacentric chromosome. As a result, one chromosome arm is somewhat shorter than the other.

Acrocentric: The acrocentric chromosome is a type of chromosome in which the centromere is more shifted towards the end of the chromosome. Thus, it makes one arm very long and the other arm very short. An extra acrocentric chromosome causes Down's syndrome and Patau's syndrome.

Telocentric: A type of chromosome in which the centromere is positioned at the terminal point of the chromosome. Therefore, it has only one arm.

Write about different types of chromosomes, based on the position of the centromere.

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