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The follicular cells of egg are held together by an adhesive cementing substance called hyaluronic acid. The acrosomal membrane disintegrates releasing the proteolytic enzyme, hyaluronidase during sperm entry through the corona radiata and zona pellucida. This is called acrosomal reaction.

Relaxin is an hormone secreted by the placenta during the later phase of pregnancy. It helps in relaxation of pelvis during child birth.

1. human Chorionic Gonadotropin (hCG) 

2. human Chorionic Somatomammotropin (hCS) 

3. relaxin

Clean and safe absorbable clothing materials, sanitary napkins, pads, tampons and menstrual cups have been identified as materials used to manage menstruation.

1. human Chorionic Gonadotropin (hCG) 

2. human Chorionic Somatomammotropin (hCS) 

3. human Placental Lactogen (hPL)

4. Oestrogen and progesterone and relaxin.

The external opening of the vagina is partially closed by a thin ring of tissue called the hymen. The hymen is often tom during the first coitus (physical union). However in some women it remains intact. It can be stretched or tom due to a sudden fall or jolt and also during strenuous physical activities such as cycling and horseback riding, etc., and therefore cannot be considered as an indicator of a woman’s virginity.

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 Lutenizing 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.

Correct Answer is: (c) 64 days

Menstrual hygiene is vital for good health, wellbeing, dignity, empowerment and productivity of women. The impact of poor menstrual hygiene on girls is increased stress levels, fear and embarrassment during menstruation. This can keep girls inactive during such periods leading to absenteeism from school.

After ovulation, the graafian follicle turns into corpus luteum (a transistory endocrine gland) which secrets progesterone. Progesterone maintain endometrium for implantation of fertilized ovum, the endometrium of uterus also secretes nutritious fluid for the foetus. Hence this phase is also referred as secretory phase.

The menstrual or ovarian cycle occurs approximately once in every 28/29 days during the reproductive life of the female from menarche (puberty) to menopause except during pregnancy. The cycle of events starting from one menstrual period till the next one is called the menstrual cycle during which cyclic changes occurs in the endometrium every month. Cyclic menstruation is an indicator of normal reproductive phase.

1. Menstrual phase 

2. Follicular or proliferative phase 

3. Ovulatory phase 

4. Luteal or secretory phase

Correct Answer is: (b) Chorion

(c) Both the statements 1 and 2 are correct.

In males, at puberty the spermatogonia (sperm mother cells) begin to undergo meiotic division and produces sperms through out life, whereas in females during the stage of foetal development, the germinal epithelial cells undergo mitosis and produce oogonia (egg mother cells) and they further enter prophase-I of meiosis-I forming primary oocytes and get arrested. No more oogonia is formed further. At puberty, out of million eggs (prime oocytes) produced at birth only 300-400 will ovulate till menopause.

(b) Spermiogenesis – Release of sperms into the cavity of seminiferous tuble.

The first ejaculation of the semen in male is called as Spermarche.

1. FSH – Follicle Stimulating Hormone 

2. LH – Luteinizing Hormone 

3. hCG – human Chorionic Gonadotropin 

4. hPL – human Placental Lactogen

Once fertilization is accomplished, cortical granules from the cytoplasm of the ovum form a barrier called the fertilization membrane around the ovum preventing further penetration of other sperms. Thus polyspermy is prevented.

inhibin is a hormone secreted by Sertoli cells of testes which is involved in the negative feedback control of sperm production.

Sertoli cells - elongated and pyramidal

 It provide nourishment to the sperms. They also secrete inhibin, a hormone (role - negative feedback control of sperm production)

It is a milky white fluid which contains sperms and the seminal plasma (secreted by accessory glands). 

The seminal fluid - acts as a transport medium, provides nutrients, contains some chemicals Role of chemical - protect and activate the sperms and also help in motility.

Testes present inside scrotal sac of skin that hangs outside the abdominal cavity. 

Scrotum is placed outside the abdominal cavity to provide a temperature 2- 3^oC lower than the normal internal body temperature to produce viable sperm. 

Thus, the scrotum acts as a thermo-regulator for spermatogenesis.

200 sperms will be produced from 50 primary spermatocytes

Colostrum mammary gland

Zygote –cleavage, blastomeres,morula,blastocyst,trophoblast, inner cell mass,attached to endometrium, diiferentiate as embryo, impalntation.

 Ectoderm, endoderm, mesoderm, stem cells.

Oxytocin (Birth Hormone)

(b) placenta as well as fully developed foetus

(d) It has more cytoplasm and more DNA than an uncleaved zygote

The release of secondary oocyte from ovary, transforms into graafian follicle.

The first cleavage in zygote produces two identical cells called blastomeres. These produce 4 cells, then 8 and so on. After 72 hours of fertilization, a loose collection of cells forms a berry shaped cluster of 16 or more cells called the morula.

Lactation is the production of milk by mammary glands. The mammary glands show changes during every menstrual cycle, during pregnancy and lactation. Increased level of oestrogens, progesterone and human Placental Lactogen (hPL) towards the end of pregnancy stimulate the hypothalamus towards prolactin – releasing factors. The anterior pituitary responds by secreting prolactin which plays a major role in lactogenesis.

The inner cell mass in the blastula is differentiated into epiblast and hypoblast immediately after implantation. The hypoblast is the embryonic endoderm and the epiblast is the ectoderm. The cells remaining in between the epiblast and the endoderm form the mesoderm. Thus the transformation of the blastocyst into a gastrula with the primary germ layers by the movement of the blastomeres is called gastrulation.

Second meiotic division

(b) Leydig cell

(c) corpus luteum in ovaries

The signals for parturition originate from fully developed foetus which induces uterine contractions triggered by oxytocin.

Endometrium is the inner layer of uterus. It assists in cyclic changes during menstruation and implantation of embryo. 

Myometrium is the middle layer of uterus. It assists in contractions of the uterus during parturition.

It is the innermost glandular layer of uterus which lines the uterine cavity. Here, implantation of blastocyst takes place. It undergoes cyclical changes during menstrual cycle.

Vigorous contraction of the uterus at the end of the pregnancy causes expulsion/delivery of the foetus. This process of delivery of the foetus (childbirth) is called parturition. 

• Parturition is induced by a complex neuroendocrine mechanism. The signals for parturition originate from the fully developed foetus and the placenta which induce mild uterine contractions called foetal ejection reflex. This triggers release of oxytocin from the maternal pituitary. Oxytocin acts on the uterine muscle and causes stronger uterine contractions, which in turn stimulates further secretion of oxytocin.

• The stimulatory reflex between the uterine contraction and oxytocin secretion continues resulting in stronger and stronger contractions. This leads to expulsion of the baby out of the uterus through the birth canal- parturition. Soon after the infant is delivered, the placenta is also expelled out of the uterus.

(b) Leydig’s cell

Inner - Endometrium.

supports foetal growth, helps in placenta formation after implantation.

Middle - Myometrium.

Exhibits strong contraction during delivery of baby.

Answer is Oxytocin

HPL and Relaxin

(d) Blastocyst

Answer is Implantation

(1) a- Zona pellucida

Function - acts as sperm receptor/prevents polyspermy.

(2) Ampullary - Isthmic junction in the fallopian tube of human female is the site of fertilization where ovum and sperm meet exactly.