Placenta is a temporary endocrine organ formed during pregnancy and it connects the foetus to the uterine wall through the umbilical cord. It is the organ by which the nutritive, respiratory and excretory functions are fulfilled

The reproductive system has four main functions namely,
(i) To produce the gametes namely sperms and ova
(ii) To transport and sustain these gametes
(iii) To nurture the developing offspring
(iv) To produce hormones

The accessory ducts associated with the male reproductive system include rete testis, vasa efferentia, epididymis and vas deferens.

Formation of gametes in males and females by spermatogenesis and oogenesis respectively

Human Chorionic Gonadotropin (hCG), Human Chorionic Somatotropin (hCS) (or) Human Placental Lactogen (hPL), oestrogens and progesterone.

Development of female gamete is called oogenesis. Oogenesis starts at the beginning of puberty.
Development of male gamete is called spermatogenesis. Spermatogenesis starts at puberty

Spermatogenesis starts at the age of puberty and is initiated due to the increase in the release of Gonadotropin-Releasing Hormone (GnRH) by the hypothalamus. GnRH acts on the anterior pituitary gland and stimulates the secretion of two gonadotropins namely Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH). FSH stimulates testicular growth and enhances the production of Androgen Binding Protein (ABP) by the Sertoli cells and helps in the process of spermiogenesis. LH acts on the Leydig cells and stimulates the synthesis of testosterone which in turn stimulates the process of spermatogenesis.

(i) Acrosome is a small cap like pointed structure present at the tip of the nucleus and is formed mainly from the Golgi body of the spermatid.
(ii) It contains hyaluronidase, a proteolytic enzyme, popularly known as sperm lysin which helps to penetrate the ovum during fertilisation.

Human Ovum
a - Vitelline membrane
b - Nucleus
c - Zona Pellucida
d - Corona radiata

i and ii

C. A is true, R is false

ii and iv

ii and iii

fertilization membrane
Reason: It is not a part of the sperm whereas the others are parts of sperm.

Orchidectomy

ovulation

The extra embryonic membranes include amnion, yolk sac, allantois, and chorion. They protect the embryo from desiccation, mechanical shock, absorption of nutrients, gaseous exchange and placental formation.