Use app×
Join Bloom Tuition
One on One Online Tuition
JEE MAIN 2025 Foundation Course
NEET 2025 Foundation Course
CLASS 12 FOUNDATION COURSE
CLASS 10 FOUNDATION COURSE
CLASS 9 FOUNDATION COURSE
CLASS 8 FOUNDATION COURSE
0 votes
157 views
in Biology by (66.5k points)
closed by
How many pairs of chromosomes are present in human beings ? Out of these how many are sex chromosomes ? How many types of sex chromosomes are found in human beings ? "The sex of a new born child is a matter of chance and none of the parents may be newborn to justify this statement.

1 Answer

+1 vote
by (67.7k points)
selected by
 
Best answer
There are 23 pairs of chromosomes present in human beings.
There is 1 pair of sex chromosomes present in human beings.
The chromosomes which determines the sex of a person are called sex chromosomes. There are two types of sex chromosomes, one is called X chromosomes and the other is called Y chromosome. Male contain one X chromosome and one Y chromosome ( XY) , while females contain two X chromosomes (X X).
Flor chart showing determination of sex of a child.
(i) A male has one X-chromosome and one Y-chromosome. Thus, half the male gametes have X-chromosomes and the other half have Y-chromosomes.
(ii) A female has two X-chromosomes. Thus all female gametes have only X-chromosomes.
(iii) If a sperm carrying Y-chromosome fertilises an ovum carrying X-chromosome, then the child born will be a boy.
(iv) If a sperm carrying X-chromosome fertilises an ovum carrying X-chromosome, then the child born will be a girl.
image
Therefore it is the sperm from the father which determines the sex of the child.

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.

Categories

...