Why is vegetative propagation practised for vowing same types of plants? However, if some variations were to be present in a few individuals in these populations, there would be some chance for them to survive. However, all variations are not necessarily beneficial for the individual organisms.
Sperm enter into the female vagina at the time of sexual intercourse. They can regenerate their lost body parts such as skin, muscles, blood, etc. For example, if the temperature of water increases suddenly, then most of the bacteria living in that water would die. The embryo gets implanted into uterus.
Answer 3: They are located outside the abdominal cavity in a sac-like structure known as scrotum. It maintains the characteristics in different generations of the species.
Oral pills can be used which change the hormonal balance and stop release of egg. This outgrowth then detaches from the body and form a new independent organism. In females, it is called tubectomy. Answer Variations are beneficial to the species than individual because sometimes for a species, the environmental conditions change so drastically that their survival becomes difficult.
The modes of reproduction in unicellular organisms can be fission, budding, etc.
The transfer of pollen grains form anther of stamen to stigma is called pollination. Intext question on page 128 are given below. Variation is thus useful for the survival of species over time.
Answer 8. Mitotic division takes place.
This is known as double fertilization as two fertilization events are taking place. Vasectomy is done by cutting the Vas deferens and then tie it up.