Which scientist designated the chromosome as the $X$-body?

$A$ man can inherit his $X$-chromosome from his

Explain the $XO$ and $XY$ types of sex determination.

Honeybees produce their young ones only by sexual reproduction. Inspite of this,in a colony of bees we find both haploid and diploid individuals. Name the haploid and diploid individuals in the colony and analyse the reasons behind their formation.

$A$ family has $9$ daughters. What is the probability of having a son at the $10$th birth (in $\%$)?

What is the number of chromosomes in the female gamete of a fruit fly ($Drosophila$ $melanogaster$)?