sci_bio

Human Chromosomes

Chapter summary, hard words and model exam answers for Class 10 Hindi.

Free online summary and notes (Class 10 Hindi). Read it here, no PDF download needed.

About the author

Biology · ICSE Class 10

Chromosomes are thread-like structures in the nucleus that carry genes. Genes contain inherited information.

Most human body cells have 46 chromosomes arranged in 23 pairs. This is the diploid number.

In humans, 22 pairs are autosomes. The 23rd pair is the sex chromosome pair: XX in females and XY in males.

Sperm and ova have 23 chromosomes each. They are haploid because they carry one set of chromosomes.

When sperm and ovum fuse, the zygote gets 23 chromosomes from each parent. The normal diploid number, 46, is restored.

A karyotype is an arranged display of chromosomes. It helps show chromosome number, size and sex chromosome pattern.

chromosome	Thread-like structure carrying genes in the nucleus
gene	Unit of inheritance located on chromosomes
autosome	Chromosome not directly involved in sex determination
sex chromosome	X or Y chromosome involved in sex determination
diploid	Having two sets of chromosomes, written 2n
haploid	Having one set of chromosomes, written n
karyotype	Arranged display of chromosomes of a cell
somatic cell	Body cell other than a gamete

🔒

You have read the summary. The board-ready model answers, grammar notes, one-touch audio and writing practice for this chapter are part of Lipi©.

See it, understand it, hear it read aloud, then write the exam answer with confidence, for a fraction of a tutor cost.