What are the changes seen in girls at the time of puberty ?
Secondary sexual characteristics in girls :
Increase in breast size and darkening of skin of the nipples present at the tips of the breasts.
Appearance of hair in the genital area.
Appearance of hair in other areas of skin like underarms, face, hands, and legs.
Increase in the size of uterus and ovary.
Beginning of menstrual cycle.
More secretion of oil from the skin, which results in the appearance of pimples.
How does reproduction help in providing stability to populations of species ?
What are the advantages of sexual reproduction over asexual reproduction ?
Can you think of reasons why more complex organisms cannot give rise to new individuals through regeneration ?
Why is vegetative propagation practised for growing some types of plants ?
What is the role of the seminal vesicles and the prostate gland ?