Umbilical cord present in act as a conduit between developing foetus and placenta. It supplies foetus  with oxygenated, nutrient rich blood from placenta and vice-versa.

Foetus heart if formed at one month of pregnancy. So, a minimum of 30 days have passed if a doctor is able to listen heartbeats.

No, semen also contains enzymes, fructose and a medium which helps in survival of sperm and provides a medium of motility.

a) Primary oocyte=46; secondary oocyte=23.
b) It is completed during fertilisation.
c) Prophase I.

a) Inner cell mass. It forms the tissues of future embryo
b) Morula
c) In the inner cell mass.
d) The pole of the blastocyst that contains the inner cell mass

In male, LH is called ICSH (Interstitial cells stimulating hormone) which stimulates the leydig cells of the testis to secrete testosterone. In females, LH promotes ovulation and controls the formation of corpus luteum after ovulation.

Yes, it is possible that the foetus gets infected. These viruses may diffuse through placenta. It may cause malformations in the developing embryo.

Reason: fertilisation can only occur if the ovum and sperms are carried simultaneously.

1.Hymen is the membrane that partially covers the vaginal opening.
2.The hymen gets torn during the first coitus.
3. But it can also be torn by active participation in sports like horse-riding,cycling,or by a sudden fall or jolt and insertion of vaginal tampon;so its presence or absence cannot indicate virginity.

(a) Two
(b) Fallopian tube