The secretions from seminal vesicles and prostate glands lubricate the sperms and provide a fluid medium for easy transport of sperms. Their secretion also provides nutrient in the form of fructose, calcium, and some enzymes.

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.

The embryo develops inside the mother's body for about nine months. Inside the uterus, the outer tissue surrounding the embryo develops finger-like projections called villi. These villi are surrounded by uterine tissue and maternal blood. They provide a large surface area for exchange of oxygen and nutrients. Also, there is a special tissue called placenta, which is embedded in the uterine wall. The embryo receives the oxygen and nutrients from the mother's blood via the placenta. The waste materials produced by the embryo are also removed through the placenta.

No. Using a copper-T will not provide a protection from sexually transmitted diseases, as it does not prevent the entry of semen. It only prevents the implantation of the embryo in the uterus.

Asexual reproduction takes place through budding in
 (a) Amoeba (b) Yeast
 (c) Plasmodium (d) Leishmania.
 
 ans (b) Yeast

Which of the following is not a part of female reproductive system in human beings?
 (a) Ovary (b) Uterus
 (c) Vas deferens (d) Fallopian tube
 
 ans : (c) Vas deferens

The anther contains
 (a) Sepals (b) Ovules
 (c) Carpel (d) Pollen grains.
 
 ans :(d) Pollen grains.

Advantages of sexual reproduction:

1.In sexual reproduction, more variations are produced. Thus, it ensures survival of species in a population.

2.The new formed individual has characteristics of both the parents.

3. Variations are more viable in sexual mode than in asexual one. This is because in asexual reproduction, DNA has to function inside the inherited cellular apparatus.