What happens during fertilisation in humans after many sperms reach close to the ovum?
1. | Only two sperms nearest the ovum penetrate zona pellucida. |
2. | Secretion of acrosome helps one sperm enter the cytoplasm of the ovum through zona pellucida. |
3. | All sperms except the one nearest to the ovum lose their tails. |
4. | Cells of corona radiata trap all the sperms except one. |
If the mammalian ovum fails to get fertilised, which one of the following is unlikely?
1. | Oestrogen secretion further decreases. |
2. | Progesterone secretion rapidly declines. |
3. | Corpus luteum will disintegrate. |
4. | Primary follicle starts developing. |
Identify the incorrectly matched pair:
1. |
Leydig cells |
Secrete androgens when stimulated by LH |
2. |
Sertoli cells |
Help in spermiogenesis and also secrete inhibin |
3. |
Seminal vesicles |
Contribute fructose to seminal plasma and store sperms |
4. |
Prostate |
Unpaired gland frequently gets enlarged in older men |
Identify the incorrect statement:
1. | Fetal ejection reflex is initiated by a fully developed fetus and placenta |
2. | Colostrum contains the IgA class of antibodies and is very important for newborn |
3. | For fertility, at least 60% of sperms in semen should show vigorous motility |
4. | The most common site of fertilization is the oviduct and that of implantation is endometrium |
In humans, the process of spermatogenesis in males and oogenesis in females are similar in:
1. | Age at which the processes begin |
2. | The number of resultant haploid cells |
3. | Cytokinesis |
4. | Occurring in respective primary sex organs |
The figure shows a secondary follicle in the ovary of a female. Identify the correct match:
(1) | (2) | (3) | (4) | |
1. | Secondary oocyte | Zona pellucida | Granulosa cells | Theca cells |
2. | Secondary oocyte | Perivitelline space | Granulosa cells | Theca cells |
3. | Primary oocyte | Zona pellucida | Theca interna | Theca externa |
4. | Primary oocyte | Zona pellucida | Granulosa cells | Theca cells |
In menopausal women you expect to find:
1. | high circulating levels of ovarian steroids but low levels of gonadotropins |
2. | high circulating levels of ovarian steroids and high levels of gonadotropins |
3. | low circulating levels of ovarian steroids but high levels of gonadotropins |
4. | low circulating levels of ovarian steroids and low levels of gonadotropins |
The regeneration of the uterine endometrium through proliferation corresponds to:
1. | the ovarian follicular phase and is regulated by estrogen |
2. | the ovarian luteal phase and is regulated by progesterone |
3. | the ovarian follicular phase and is regulated by progesterone |
4. | the ovarian luteal phase and is regulated by estrogen |
In the given diagram showing a blastocyst in human embryonic development:
I: | Both 3 and 5 are parts of inner cell mass and contribute to the embryo |
II: | 4 becomes the future amniotic cavity and prevents desiccation of the embryo |
III. | 2 is the outer cell mass and contributes to the placenta and ectoderm of the embryo |
1. | Only I is correct |
2. | Only I and III are correct |
3. | Only I and II are incorrect |
4. | I, II, and III are incorrect |
Before the placenta takes over, what structure secretes large amounts of progesterone to support pregnancy?
1. | Corpus Albicans | 2. | Graafian follicle |
3. | Chorion | 4. | Corpus luteum |