The luteal phase of the menstrual cycle begins after ovulation occurs on Day 14 and continues until the first day of your period (Day 1). It is also known as the premenstrual phase or the ovulatory phase. It’s called the secretory phase. During the secretory phase, the progesterone released by the corpus luteum in the ovaries stimulates the endometrium to secrete substances called prostaglandins (PGs). Answer : (d)

Spermatogenesis is the production of sperm from the primordial germ cells. Spermatogenesis is the process by which haploid spermatozoa develop from germ cells in the seminiferous tubules of the testis. Answer : (c)

In 28 - day human ovarian cycle, ovulation occurs on day 14.Ovulation, release of a mature egg from the female ovary Answer : (c)

In a pregnant female, high levels of HCG will maintain corpus luteum and stimulate it to secrete oestrogen and progesterone. In a normal pregnant woman, the amount of total gonadotropin activity was assessed. The result expected was High levels of FSH and LH in uterus to stimulate endometrial thickening High level of circulating hCG to stimulate estrogen and progesterone synthesis Answer : (b)

Secondary spermatocytes are haploid (N) cells that contain half the number of chromosomes. A spermatogonium is an undifferentiated male germ cell each human Spermatogonium ( germ stem cell) gives rise to many Spermatogonia by mitosis. So the number of chromosomes in each Spermatogonium cell is conserved at 46 chromosomes. Primary spermatocytes are diploid (2N) cells Answer : (c)

Primary spermatocytes are diploid (2N) cells. After meiosis I, two secondary spermatocytes are formed. Secondary spermatocytes are haploid (N) cells that contain half the number of chromosomes. Thus ONE Primary spermatocytes produces 4 sperms Answer : (d)

The signals for parturition originate from the fully-developed foetus and the placenta which requires the release of oxytocin from the posterior lobe of the maternal pituitary Answer : (c)

The cervix is the lower part of the uterus situated between the external os (external orifice) and internal os (internal orifice). Answer : (c)

Cryptorchidism Occurs when a boy is born with one or both testicles in the lower abdomen rather than the scrotum. Known also as undescended testicles Answer : (a)

Mitosis of the spermatogonia	16 days	Up to the primary spermatocytes Spermatogonia A & B
First meiosis	24 days	For the division of the primary spermatocytes to form secondary spermatocytes
Second meiosis	A few hours	For engendering the spermatids
Spermiogenesis	24 days	Up to the completed sperm cells
Total	~64 days	- -

The approximate 64 day cycle of the spermatogenesis can be subdivided into four phases that last differing lengths of time: Answer : (b)

Answer : (b)

Many hormone levels change in the body during pregnancy, with several hormones playing major roles during pregnancy. These include: Human chorionic gonadotropin hormone (hCG). This hormone is only produced during pregnancy —almost exclusively in the placenta. HCG hormone levels found in maternal blood and urine increase dramatically during the first trimester and may contribute to nausea and vomiting that are often associated with pregnancy. Human placental lactogen (hPL). This hormone, produced by the placenta, helps provide nutrition to the fetus and plays a role in stimulating milk glands in the breasts in anticipation of breastfeeding. Estrogen. This group of hormones is responsible for developing the female sexual characteristics. Normally formed in the ovaries, estrogen is also produced by the placenta during pregnancy to help maintain a healthy pregnancy. Progesterone. This hormone is produced by the ovaries and by the placenta during pregnancy. Progesterone stimulates the thickening of the uterine lining in anticipation of implantation of a fertilized egg. Answer : (b)

In mammalian fertilization, hyaluronidase is released by the acrosome of the sperm cell after it has reached the oocyte, by digesting hyaluronan in the corona radiata, thus enabling conception. Answer : (b)

Besides activating the egg another role of sperm is to carry DNA to egg. Answer : (d)

If the egg is not fertilized, the corpus luteum will degenerate and form the corpus albicans. Corpus callosum a broad band of nerve fibres joining the two hemispheres of the brain. Corpora Bigemina) In invertebrate zoology, a lateral lobe of the forebrain in certain arthropods. The corpora quadrigemina controls the position of the head and eyes in response to visual, auditory, and somatic stimuli as well as transmits auditory signals to the auditory center in the cerebral cortex. Answer : (a)

Morula	Blastula
A solid cell mass	A hollow structure
Morula is a solid ball of cells resulting from division of fertilized ovum and from which a blastula is formed	Blastula is a hollow sphere of cells surrounding the blastocoele produced during the development of an embryo
Consists of more than a hundred of cells	Consists of hundred and twenty cells
Consists of ball of small, spherical cells formed by the rapid cleavage of zygote	Consists of a spherical cell layer of blastomeres and fluid-filled cavity called blastocoel
Forms 4-5 days after fertilization	Forms 5-10 days after fertilization

Answer : (d)

Ordinarily, the release of eggs ceases once a woman is pregnant, and the hormonal and physical changes of pregnancy work together to prevent another conception. Thus option c is not correct statement Answer : (c)

Cortical granules are regulatory secretory organelles (ranging from 0.2 um to 0.6 um in diameter) found within oocytes and are most associated with polyspermy prevention after the event of fertilization. Answer : (d)

Asthenospermia is defined as < 40% sperm motility or less than 32% with progressive motility Azoospermia means that a man does not have a measurable amount of sperm in his ejaculate. Polyspermy describes an egg that has been fertilized by more than one sperm. Terms oligospermia, oligozoospermia, and low sperm count refer to semen with a low concentration of sperm Answer : (d)

If the egg isn't fertilized, the corpus luteum breaks down, leading to a drop in progesterone levels. This decrease causes the endometrium to break down, causing the beginning of menstrual period The hormone drop causes the uterus to shed its lining in a process termed menstruation . Answer : (c)

Menarche is the first menstrual cycle, or first menstrual bleeding, Answer : (b)

Answer : (c)

Tunica vasculosa is the first thin layer of blood vessels. This layer shields the tubular interior of each testicle from further layers of tissue around the outer testicle. The next layer is called the tunica albuginea. It’s a thick, protective layer made of densely packed fibers that further protect the testes. In artery, the outermost coat, or tunica adventitia, is a tough layer consisting mainly of collagen fibres that act as a supportive element. The tunica media or media for short, is the middle tunica (layer) of an artery or vein. Answer : (d)

The inner lining of the uterus (the endometrium) goes through three phases during the typically 28 day menstrual cycle: the menstrual phase (days 1-5) The proliferative phase (days 6-14) and The secretory phase (days 15-28). The ovarian cycle, refers to the cycle in which a woman’s ovaries prepare an egg to be released during ovulation Answer : (c)

Progesterone is a hormone released by the corpus luteum in the ovary Answer : (a)

The mode of cleavage is determined by the amount of yolk and its distribution.(I) Holoblastic - The cleavage, in which the segmentation lines pass through the entire egg, dividing it completely, eg, frog, human egg, etc.(II) Meroblastic -The lines of segmentation do not completely pass through the egg and remain confined to a part of the egg, eg , insects, birds, reptiles. Answer : (a)

Amniocentesis is a medical procedure used primarily in prenatal diagnosis of chromosomal abnormalities and fetal infections as well as for sex determination. Thus Assertion and Reason are true but Reason is not correct explanation of Assertion Answer : (b)

Sperm is an highly motile structure . The energy comes from the large number of mitochondria present in the mid piece . Er ,ribosome , golgi bodies are needed in cells which undergo metabolism but sperms survive on glucose which needs no metabolism so there is no use of golgi bodies and sperm has no use of proteins so it is devoid of ribosomes and Er and its main aim is to contract the nucleus in such a short space . The DNA in sperm is coiled more extensively to accommodate it in a small space . More number of mitochondria more the motility which inturn increases the fertilization rate Answer : (d)

Answer : (a)

The ampulla of the tube is the most lateral portion of the fallopian tube, terminates at the funnel-shaped infundibulum, which has a fimbriated end that drapes over the ovary Answer : (d)