Question

In a butterfly has chromosomes number 360 in its meiocyte 2n. What will be the chromosome number in its gametes?
A. 380
B. 180
C. 95
D. 760

Answer 1

Hint: The thread-like structures which are present in the nucleus and carry genetic information from one generation to another are known as chromosomes. The number of chromosomes vary from species to species but is constant in all cells for any species.

Complete Answer:
Before we find the correct answer, let us know a little more about chromosomes first. Every chromosome is present in a pair and they are known as homologous chromosomes. The chromosomes are made up of chromatin and they contain a single molecule of DNA and the associated proteins.

Now, if the chromosome is unpaired it is said to be in haploid stage (n), i.e. every cell has one chromosome only (half the usual number). But, if the chromosome is paired it is said to be in diploid stage (2n), i.e. every cell has one pair of chromosomes each.
In butterfly, chromosome number in meiocytes
$2n=360$
Gametes (n) $=\dfrac{360}{2}=180$

Hence the correct answer is option B.

Note: The various functions of chromosomes are,
- They protect DNA from getting tangled and damaged.
- They play an important role and also act as a guiding force in the reproduction, regeneration and repair process which is important for survival.
- The presence of histone and nonhistone proteins help in regulation of gene expression.
- Their major function is to carry genetic material from one generation to another.