Question

what are sex chromosomes ? what are they named so

Answer 1

There are total 46 chromosomes present in human body, i.e. total 23 pairs. One pair is of the sex chromosome. The sex chromosome determine the sex (gender) of the baby. Hence, they are named 'sex chromosomes'.

Answer 2

Sex chromosomes are the heredity materials which are present inside the sex cells/ gametes of a multicellular organism whose mode of reproduction is sexual.
They contain the DNA which controls the overall character of a particular person..
They are named so because they are present in the sex cells which is haploid( contains only 23 chromosome) of an organism
Thus the zygote formed has the characteristic of both their parents