Which contraceptive device is used only by males?

In a tobacco plant,the male gametes have $24$ chromosomes. What is the number of chromosomes in the female gamete? What is the number of chromosomes in the zygote?

What should the temperature of the testes be relative to the body temperature for the production of sperm?

Which among the following statements are true for sexual reproduction in flowering plants?
$(i)$ It requires two types of gametes
$(ii)$ Fertilisation is a compulsory event
$(iii)$ It always results in formation of zygote
$(iv)$ Offspring formed are clones

"The consistency of $DNA$ copying during reproduction is important for the maintenance of body design features." Support this statement with two arguments.

In which plant does vegetative reproduction occur through the stem?