In some plants the flower bud modifies into globose bulb which are called as bulbils. When these fall on the ground they grow into new plants. eg Agave.

The need for contraception is control birth.

Hormone responsible for the vigorous contractions of the uterine muscles is oxytocin.

Endosperm provides food to the developing embryo.

Hydra and yeast are the organisms which are reproduces through budding

(i) The spermatozoan consists of head, a middle piece and tail.
(ii) The sperm head is elongated and formed by the condensation of nucleus.
(iii) The anterior portion has a cap like structure called acrosome.
(iv) It contains hyaluronidase, an enzyme that helps the sperm to enter the ovum during fertilization.
(v) A short neck connects the head and middle piece which comprises the centrioles.
(vi) The middle piece contains the mitochondria which provides energy for the movement of tail.
(vii) It brings about sperm motility which is essential for fertilization.

A - Exine
B - Intine
C - Generative cell
D - Vegetative nucleus

(i) The first fluid which is released from the mammary gland after child birth is called as colostrum.
(ii) Milk production from alveoli of mammary glands is stimulated by prolactin secreted from the anterior pituitary.
(iii) The ejection of milk is stimulated by posterior pituitary hormone oxytocin.

(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.

The reproductive period is marked by characteristic events repeated almost every month in physiologically normal woman (28 days with minor variation) in the form of a menstrual flow
The menstrual cycle consists of 4 phases:
(i) Menstrual or Destructive phase 
(ii) Follicular or Proliferative Phase
(iii) Ovulatory Phase
(iv) Luteal or Secretory Phase