(a) Fertilization occurs in the oviduct of the female general tract.
(b) Implantation occurs in uterus.

The need for contraception is control birth.

Endosperm provides food to the developing embryo.

The germination of pollen grains takes place in stigma.

The secondary sex organs in male include the vas deferens, epididymis, seminal vesicle, prostate gland and penis.

(i) In the fertilization one sperm fuses with egg and forms a diploid zygote.
(ii) The other sperm fuses with secondary nucleus (Triple Fusion) to form primary endosperm nucleus which is triploid in nature
(iii) This fusion is called triple fusion.

(i) The main part of the ovule is the nucellus which is enclosed by two integuments leaving an opening called as micropyle.
(ii) The ovule is attached to the ovary wall by a stalk known as funiculus.
(iii) Chalaza is the basal part.
(iv) The embryo sac contains seven cells and eight nuclei located within the nucellus.
(v) Three cells at the micropylar end form the egg apparatus and the three cells at the chalaza end are the antipodal cells.
(vi) The remaining two nuclei are called polar nuclei found in the centre.
(vii) In the egg apparatus one is the egg cell (female gamete) and the remaining two cells are the synergids.