Here below we cover basic human reproduction MCQ (multiple choice question) question with answer for any compitative exam. Lets check one by one.
- Which of the following hormone is responsible for ovulation?
a) FSH
b) LH
c) Estrogen
d) Progesterone
Answer: b) LH
Explanation:
The luteinizing hormone (LH) surge triggers ovulation. It causes the rupture of the Graafian follicle, releasing the ovum. Follicle-stimulating hormone (FSH) helps in follicle growth, while estrogen and progesterone regulate different stages of the menstrual cycle.
- Which of the following cells in the testes secrete testosterone?
a) Sertoli cells
b) Leydig cells
c) Spermatogonia
d) Spermatocytes
Answer: b) Leydig cells
Explanation:
Leydig cells, also known as interstitial cells, are responsible for producing testosterone in the presence of luteinizing hormone (LH). Sertoli cells provide nourishment to sperm cells.
- What is the site of fertilization in humans?
a) Vagina
b) Uterus
c) Fallopian tube
d) Ovary
Answer: c) Fallopian tube
Explanation:
Fertilization in humans typically occurs in the ampulla, a part of the fallopian tube. After the sperm meets the egg here, the fertilized egg (zygote) travels to the uterus for implantation.
- Which layer of the uterus is shed during menstruation?
a) Myometrium
b) Endometrium
c) Perimetrium
d) Exometrium
Answer: b) Endometrium
Explanation:
The endometrium is the innermost lining of the uterus that thickens during the menstrual cycle in preparation for potential pregnancy. If fertilization does not occur, this layer is shed during menstruation.
- The process of sperm maturation occurs in the:
a) Seminiferous tubules
b) Vas deferens
c) Epididymis
d) Urethra
Answer: c) Epididymis
Explanation:
Sperm are produced in the seminiferous tubules but undergo maturation and gain motility in the epididymis. This process ensures that the sperm are capable of fertilizing an ovum.
- What is the name of the hormone responsible for the maintenance of pregnancy?
a) Estrogen
b) Progesterone
c) Oxytocin
d) Prolactin
Answer: b) Progesterone
Explanation:
Progesterone is crucial for maintaining the endometrial lining of the uterus, which is essential for a successful pregnancy. It prevents uterine contractions and supports the embryo’s development.
- Which of the following prevents polyspermy during fertilization?
a) Zona pellucida reaction
b) Acrosome reaction
c) Cortical reaction
d) Capacitation
Answer: c) Cortical reaction
Explanation:
The cortical reaction occurs after a sperm enters the egg, releasing enzymes from cortical granules that modify the zona pellucida to prevent further sperm from entering, thus avoiding polyspermy.
- The fetal part of the placenta is derived from:
a) Endometrium
b) Chorion
c) Amnion
d) Allantois
Answer: b) Chorion
Explanation:
The fetal part of the placenta is derived from the chorion, which develops from the trophoblast cells. The placenta plays a vital role in nutrient exchange between the mother and the fetus.
- At what stage is the oocyte arrested in a newborn female?
a) Primary oocyte in prophase I
b) Secondary oocyte in metaphase II
c) Oogonia
d) Zygote
Answer: a) Primary oocyte in prophase I
Explanation:
In a newborn female, oocytes are arrested in the diplotene stage of prophase I of meiosis. They remain in this stage until puberty, when they resume meiotic division during ovulation.
- Which of the following is the correct sequence of sperm formation?
a) Spermatogonia → Spermatocyte → Spermatid → Sperm
b) Spermatocyte → Spermatogonia → Spermatid → Sperm
c) Spermatid → Spermatogonia → Spermatocyte → Sperm
d) Sperm → Spermatid → Spermatogonia → Spermatocyte
Answer: a) Spermatogonia → Spermatocyte → Spermatid → Sperm
Explanation:
Spermatogenesis begins with spermatogonia (stem cells), which differentiate into primary spermatocytes. These then undergo meiosis to form spermatids, which finally mature into spermatozoa (sperm).
- What is the function of the acrosome in sperm?
a) Protects sperm from the acidic environment of the vagina
b) Contains enzymes to penetrate the egg
c) Provides energy for sperm motility
d) Maintains sperm shape
Answer: b) Contains enzymes to penetrate the egg
Explanation:
The acrosome, located at the tip of the sperm head, contains hydrolytic enzymes that digest the zona pellucida of the egg, allowing the sperm to penetrate and fertilize the ovum.
- Which hormone stimulates milk production after childbirth?
a) Progesterone
b) Oxytocin
c) Prolactin
d) LH
Answer: c) Prolactin
Explanation:
Prolactin is the hormone responsible for stimulating milk production in the mammary glands after childbirth. Oxytocin aids in milk ejection, while progesterone and LH are not directly involved in lactation.
- At what stage of embryonic development does implantation occur?
a) Zygote
b) Morula
c) Blastocyst
d) Gastrula
Answer: c) Blastocyst
Explanation:
Implantation of the embryo in the uterus occurs at the blastocyst stage, about 5-7 days after fertilization. The blastocyst attaches to the uterine wall and begins the process of embedding into the endometrium.
- Which of the following structures forms the placenta?
a) Chorion and endometrium
b) Chorion and amnion
c) Allantois and yolk sac
d) Amnion and yolk sac
Answer: a) Chorion and endometrium
Explanation:
The placenta is formed by the interaction between the chorion (fetal tissue) and the endometrium (maternal tissue). It facilitates the exchange of nutrients, gases, and waste between the mother and the fetus.
- Which of the following assists in the descent of testes into the scrotum?
a) Sertoli cells
b) Gubernaculum
c) Vas deferens
d) Epididymis
Answer: b) Gubernaculum
Explanation:
The gubernaculum is a fibrous structure that helps in the descent of the testes from the abdominal cavity into the scrotum during fetal development, a process essential for normal sperm production in males.
- The inner cell mass of the blastocyst gives rise to which of the following?
a) Placenta
b) Trophoblast
c) Embryo
d) Chorion
Answer: c) Embryo
Explanation:
The inner cell mass (ICM) of the blastocyst develops into the embryo. The trophoblast cells form the outer layer, which contributes to the placenta.
- Which of the following structures is derived from the ectoderm?
a) Nervous system
b) Muscular system
c) Digestive system
d) Circulatory system
Answer: a) Nervous system
Explanation:
The ectoderm gives rise to the nervous system, including the brain and spinal cord, as well as the skin. The muscular and circulatory systems are derived from the mesoderm, while the digestive system comes from the endoderm.
- How many sperms are produced from one primary spermatocyte?
a) 1
b) 2
c) 3
d) 4
Answer: d) 4
Explanation:
One primary spermatocyte undergoes meiosis to produce four haploid sperm cells. Meiosis I results in two secondary spermatocytes, and meiosis II results in four spermatids, which differentiate into mature sperm.
- Which hormone primarily controls the menstrual cycle in females?
a) Testosterone
b) Insulin
c) Estrogen and progesterone
d) Adrenaline
Answer: c) Estrogen and progesterone
Explanation:
Estrogen and progesterone regulate the menstrual cycle. Estrogen helps in the proliferation of the endometrial lining, while progesterone maintains it in preparation for a potential pregnancy. A drop in these hormones leads to menstruation.
- Which of the following structures develops into the male reproductive ducts?
a) Müllerian ducts
b) Wolffian ducts
c) Cloaca
d) Urachus
Answer: b) Wolffian ducts
Explanation:
The Wolffian ducts (mesonephric ducts) develop into the male reproductive structures, including the vas deferens and epididymis. In females, the Müllerian ducts develop into reproductive structures like the fallopian tubes, uterus, and upper part of the vagina.
- Which of the following is the primary function of the Sertoli cells in the testes?
a) Production of testosterone
b) Nourishment and support of sperm cells
c) Transportation of sperm
d) Storage of sperm
Answer: b) Nourishment and support of sperm cells
Explanation:
Sertoli cells, also known as nurse cells, provide nourishment, protection, and structural support to developing sperm cells during spermatogenesis. They also help in the formation of the blood-testis barrier and release hormones like inhibin to regulate sperm production.
- Which hormone is responsible for the contraction of the uterus during childbirth?
a) Estrogen
b) Oxytocin
c) Progesterone
d) Relaxin
Answer: b) Oxytocin
Explanation:
Oxytocin is the hormone responsible for stimulating uterine contractions during labor, helping to push the baby through the birth canal. It also aids in milk ejection from the mammary glands during breastfeeding.
- Which of the following structures in males is homologous to the female clitoris?
a) Glans penis
b) Scrotum
c) Urethra
d) Prostate gland
Answer: a) Glans penis
Explanation:
The glans penis in males is homologous to the clitoris in females, meaning both structures develop from the same embryonic tissue and have similar nerve endings, making them highly sensitive to touch.
- The phase of the menstrual cycle during which the endometrium is thickest and most prepared for implantation is called:
a) Menstrual phase
b) Proliferative phase
c) Secretory phase
d) Follicular phase
Answer: c) Secretory phase
Explanation:
The secretory phase occurs after ovulation when progesterone from the corpus luteum causes the endometrium to become highly vascularized and glandular, preparing it for possible implantation of a fertilized egg.
- The fluid-filled cavity in the blastocyst is known as the:
a) Amniotic cavity
b) Chorionic cavity
c) Blastocoel
d) Yolk sac
Answer: c) Blastocoel
Explanation:
The blastocoel is a fluid-filled cavity that forms within the blastocyst during early embryonic development. It helps maintain the structure of the blastocyst and plays a role in the differentiation of cells into the inner cell mass and trophoblast.
- During which stage of pregnancy does the fetus begin to make voluntary movements?
a) First trimester
b) Second trimester
c) Third trimester
d) Just before birth
Answer: b) Second trimester
Explanation:
Voluntary fetal movements, also known as “quickening,” typically begin during the second trimester (around 18–20 weeks). This is when the mother can first feel the fetus moving.
- The hormone detected in pregnancy tests is:
a) Luteinizing hormone (LH)
b) Follicle-stimulating hormone (FSH)
c) Human chorionic gonadotropin (hCG)
d) Progesterone
Answer: c) Human chorionic gonadotropin (hCG)
Explanation:
Pregnancy tests detect the presence of human chorionic gonadotropin (hCG), a hormone produced by the placenta shortly after implantation. The levels of hCG rise significantly in early pregnancy.
- The first meiotic division of the oocyte occurs at which stage of the menstrual cycle?
a) After fertilization
b) Before ovulation
c) At ovulation
d) After implantation
Answer: c) At ovulation
Explanation:
The primary oocyte is arrested in prophase I until ovulation, when it completes the first meiotic division to become a secondary oocyte. The second meiotic division occurs only if fertilization takes place.
- Which of the following structures prevents the entry of more than one sperm during fertilization?
a) Corona radiata
b) Zona pellucida
c) Acrosome
d) Blastocoel
Answer: b) Zona pellucida
Explanation:
The zona pellucida is a glycoprotein layer surrounding the egg that, after the first sperm penetrates, undergoes biochemical changes (cortical reaction) to prevent additional sperm from entering, thus ensuring monospermy.
- Which of the following embryonic layers gives rise to the heart and blood vessels?
a) Ectoderm
b) Mesoderm
c) Endoderm
d) Neural crest
Answer: b) Mesoderm
Explanation:
The mesoderm is the middle germ layer in the embryo that differentiates into various structures, including the cardiovascular system (heart, blood vessels), muscles, bones, and kidneys.
These additional MCQs further enhance the coverage of essential concepts in Human Reproduction for NEET 2025 preparation, helping to solidify key knowledge areas.
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Here are more NEET 2025 Human Reproduction MCQs with answers and explanations:
- Which of the following structures forms the maternal part of the placenta?
a) Chorion
b) Endometrium
c) Amnion
d) Trophoblast
Answer: b) Endometrium
Explanation:
The maternal part of the placenta is derived from the endometrium, which is the inner lining of the uterus. The fetal part comes from the chorion, which originates from the trophoblast.
- Which hormone is primarily responsible for the development of secondary sexual characteristics in females?
a) Progesterone
b) Oxytocin
c) Estrogen
d) Testosterone
Answer: c) Estrogen
Explanation:
Estrogen is the hormone that promotes the development of secondary sexual characteristics in females, such as breast development, widening of the hips, and the regulation of the menstrual cycle.
- At which stage of human embryonic development does gastrulation occur?
a) Blastocyst
b) Morula
c) Gastrula
d) Zygote
Answer: c) Gastrula
Explanation:
Gastrulation occurs at the gastrula stage, where the embryo develops three germ layers: ectoderm, mesoderm, and endoderm. This process establishes the basic body plan of the organism.
- Which of the following is the correct sequence of events during childbirth?
a) Dilation → Expulsion → Placental stage
b) Expulsion → Dilation → Placental stage
c) Placental stage → Dilation → Expulsion
d) Dilation → Placental stage → Expulsion
Answer: a) Dilation → Expulsion → Placental stage
Explanation:
Childbirth occurs in three stages: the dilation stage (where the cervix dilates to allow the baby to pass), the expulsion stage (delivery of the baby), and the placental stage (delivery of the placenta).
- What is the primary function of the amniotic fluid?
a) Nutrition of the fetus
b) Protection of the fetus from mechanical injury
c) Providing oxygen to the fetus
d) Facilitating waste removal
Answer: b) Protection of the fetus from mechanical injury
Explanation:
Amniotic fluid surrounds the developing fetus in the amniotic sac, cushioning it from external shocks, maintaining a stable temperature, and allowing fetal movement for proper musculoskeletal development.
- Which of the following cells undergoes the first meiotic division to produce secondary spermatocytes?
a) Spermatogonia
b) Primary spermatocyte
c) Spermatid
d) Spermatozoa
Answer: b) Primary spermatocyte
Explanation:
Primary spermatocytes undergo the first meiotic division to produce two haploid secondary spermatocytes. These then divide further in the second meiotic division to produce spermatids, which mature into spermatozoa (sperm).
- Which of the following is a key role of FSH in the male reproductive system?
a) Production of testosterone
b) Stimulation of Sertoli cells for spermatogenesis
c) Induction of ejaculation
d) Maintenance of the epididymis
Answer: b) Stimulation of Sertoli cells for spermatogenesis
Explanation:
In males, follicle-stimulating hormone (FSH) stimulates the Sertoli cells, which are essential for supporting the process of spermatogenesis (sperm production). FSH, along with testosterone, ensures proper sperm development.
- Which of the following is NOT a function of the placenta?
a) Nutrient exchange
b) Gas exchange
c) Waste elimination
d) Production of sperm
Answer: d) Production of sperm
Explanation:
The placenta plays a vital role in the exchange of nutrients, gases (oxygen and carbon dioxide), and waste products between the mother and the fetus. However, sperm production is a function of the male reproductive system, specifically the testes.
- Which hormone is responsible for inhibiting FSH secretion to prevent the development of multiple follicles during the menstrual cycle?
a) Inhibin
b) Estrogen
c) Progesterone
d) LH
Answer: a) Inhibin
Explanation:
Inhibin is produced by the granulosa cells of the ovaries and inhibits the secretion of FSH (follicle-stimulating hormone). This helps regulate the menstrual cycle and prevents the development of multiple follicles.
- Which of the following methods is used to detect fetal abnormalities early in pregnancy?
a) Ultrasound
b) Amniocentesis
c) MRI
d) X-ray
Answer: b) Amniocentesis
Explanation:
Amniocentesis is a diagnostic procedure used to detect chromosomal abnormalities and genetic disorders in the fetus by analyzing a sample of amniotic fluid. It is usually performed in the second trimester. Ultrasound is also commonly used for non-invasive fetal monitoring, but it does not provide genetic information.
- Which of the following events occurs during the luteal phase of the menstrual cycle?
a) Ovulation
b) Follicular development
c) Progesterone secretion by the corpus luteum
d) Estrogen peaks and declines
Answer: c) Progesterone secretion by the corpus luteum
Explanation:
The luteal phase begins after ovulation. The ruptured follicle transforms into the corpus luteum, which secretes progesterone to maintain the endometrium in case of fertilization. If pregnancy does not occur, the corpus luteum degenerates, leading to a drop in progesterone and the onset of menstruation.
- The sperm’s ability to fertilize an egg is acquired in which part of the male reproductive system?
a) Testes
b) Prostate gland
c) Epididymis
d) Vas deferens
Answer: c) Epididymis
Explanation:
Sperm acquire the ability to fertilize an egg during their maturation in the epididymis. The process involves gaining motility and the ability to recognize and penetrate the egg’s protective layers.
- The chorionic villi are involved in:
a) Nutrient and gas exchange between the mother and fetus
b) Protection of the fetus from infections
c) Hormonal secretion for lactation
d) Maintenance of amniotic fluid levels
Answer: a) Nutrient and gas exchange between the mother and fetus
Explanation:
Chorionic villi are finger-like projections that extend into the endometrium and form part of the placenta. They play a crucial role in facilitating the exchange of nutrients, gases, and waste between the maternal and fetal blood.
- Which of the following occurs during capacitation of sperm?
a) Sperm mature in the testes
b) Sperm become motile in the epididymis
c) Sperm undergo biochemical changes to fertilize the egg
d) Sperm are stored in the seminal vesicle
Answer: c) Sperm undergo biochemical changes to fertilize the egg
Explanation:
Capacitation is a process that occurs in the female reproductive tract after ejaculation, where sperm undergo physiological changes, enhancing their ability to penetrate the egg’s zona pellucida and fertilize it.
- In a 28-day menstrual cycle, on which day does ovulation typically occur?
a) 1st day
b) 7th day
c) 14th day
d) 21st day
Answer: c) 14th day
Explanation:
In a typical 28-day menstrual cycle, ovulation occurs around the 14th day. This is when the mature egg is released from the ovary and is available for fertilization. The timing may vary depending on the length of the individual’s cycle.
- Which of the following is true about the placenta?
a) It secretes hCG
b) It stores oxygen for the fetus
c) It produces prolactin during pregnancy
d) It prevents maternal hormones from affecting the fetus
Answer: a) It secretes hCG
Explanation:
The placenta secretes human chorionic gonadotropin (hCG), which helps maintain the corpus luteum and the production of progesterone in the early stages of pregnancy. This hormone is also detected in pregnancy tests.
- Which of the following occurs when the zona pellucida of the ovum is penetrated by a sperm?
a) Completion of the first meiotic division
b) Completion of the second meiotic division
c) Fusion of the nucleus of the sperm and egg
d) Formation of the corpus luteum
Answer: b) Completion of the second meiotic division
Explanation:
Once a sperm penetrates the zona pellucida and fuses with the egg, the secondary oocyte completes its second meiotic division, resulting in the formation of a mature ovum and the release of a polar body.
- What role does relaxin play during pregnancy?
a) Stimulates the secretion of milk
b) Relaxes the pubic symphysis and cervix
c) Stimulates uterine contractions
d) Initiates the release of oxytocin
Answer: b) Relaxes the pubic symphysis and cervix
Explanation:
Relaxin is a hormone produced during pregnancy that helps relax the pubic symphysis (the joint between the two halves of the pelvis) and softens the cervix to prepare for childbirth.
- Which of the following happens during the acrosome reaction?
a) The sperm is activated for motility
b) Enzymes are released to digest the zona pellucida
c) The sperm completes meiosis
d) The sperm and egg nuclei fuse
Answer: b) Enzymes are released to digest the zona pellucida
Explanation:
During the acrosome reaction, enzymes are released from the acrosome (a cap-like structure on the head of the sperm) to digest the zona pellucida, allowing the sperm to penetrate and fertilize the egg.
- What is the function of the trophoblast in early pregnancy?
a) It becomes the embryo
b) It forms the amniotic sac
c) It secretes hCG to maintain the corpus luteum
d) It forms the fetal part of the umbilical cord
Answer: c) It secretes hCG to maintain the corpus luteum
Explanation:
The trophoblast, which is the outer layer of the blastocyst, secretes human chorionic gonadotropin (hCG). This hormone maintains the corpus luteum, ensuring the continued production of progesterone, which is essential for sustaining the pregnancy.
These additional questions deepen the understanding of key processes and structures involved in Human Reproduction, crucial for NEET preparation.
- The process by which sperm is released from the testes into the vas deferens is known as:
a) Spermiogenesis
b) Spermiation
c) Spermatogenesis
d) Capacitation
Answer: b) Spermiation
Explanation:
Spermiation is the process by which mature spermatozoa are released from the Sertoli cells into the lumen of the seminiferous tubules, from where they move to the epididymis and later enter the vas deferens.
- Which of the following enzymes helps sperm penetrate the zona pellucida of the ovum?
a) Amylase
b) Hyaluronidase
c) DNAse
d) Pepsin
Answer: b) Hyaluronidase
Explanation:
Hyaluronidase is an enzyme released from the sperm’s acrosome that helps digest the extracellular matrix surrounding the egg, including the zona pellucida, thus allowing the sperm to penetrate the egg during fertilization.
- The period when the embryo is most susceptible to the effects of teratogens is during:
a) Fertilization
b) Organogenesis
c) Implantation
d) Gastrulation
Answer: b) Organogenesis
Explanation:
The embryo is most susceptible to teratogens during organogenesis, which is the period of rapid cell differentiation and organ formation, typically occurring during the first trimester (especially weeks 3 to 8).
- Which of the following structures secretes progesterone after ovulation?
a) Follicle
b) Endometrium
c) Corpus luteum
d) Oviduct
Answer: c) Corpus luteum
Explanation:
After ovulation, the remaining follicle cells transform into the corpus luteum, which secretes progesterone. Progesterone is essential for maintaining the endometrium and supporting early pregnancy.
- What is the primary role of oxytocin during lactation?
a) Stimulating milk production
b) Inhibiting prolactin secretion
c) Stimulating milk ejection
d) Stimulating breast growth
Answer: c) Stimulating milk ejection
Explanation:
Oxytocin is responsible for the milk ejection reflex (or let-down reflex) during lactation. When the baby suckles, oxytocin causes the smooth muscles around the mammary glands to contract, ejecting milk through the nipple.
- Which part of the sperm contains enzymes that assist in penetrating the egg during fertilization?
a) Nucleus
b) Mitochondria
c) Acrosome
d) Tail
Answer: c) Acrosome
Explanation:
The acrosome is a cap-like structure at the head of the sperm, which contains enzymes (such as hyaluronidase) that help the sperm penetrate the egg’s protective layer (zona pellucida) during fertilization.
- The morula stage in embryonic development is characterized by:
a) A single cell
b) A hollow ball of cells
c) A solid ball of cells
d) Formation of three germ layers
Answer: c) A solid ball of cells
Explanation:
The morula is a solid ball of cells formed by successive cleavage divisions after the zygote stage. It later develops into a blastocyst, which contains a fluid-filled cavity and distinct cellular layers.
- Which of the following events takes place during the follicular phase of the menstrual cycle?
a) Ovulation
b) Corpus luteum formation
c) Endometrial shedding
d) Follicular maturation
Answer: d) Follicular maturation
Explanation:
The follicular phase is characterized by the maturation of ovarian follicles under the influence of FSH (follicle-stimulating hormone). It culminates in ovulation, where the mature follicle releases the egg.
- Which of the following is the primary site of fertilization in humans?
a) Uterus
b) Ovary
c) Fallopian tube
d) Cervix
Answer: c) Fallopian tube
Explanation:
Fertilization in humans typically occurs in the ampulla of the fallopian tube, which is the widest section of the tube. The fertilized egg then travels to the uterus for implantation.
- The hormone responsible for milk production during lactation is:
a) Oxytocin
b) Estrogen
c) Progesterone
d) Prolactin
Answer: d) Prolactin
Explanation:
Prolactin is the hormone produced by the anterior pituitary gland that stimulates the production of milk in the mammary glands after childbirth. It works in conjunction with oxytocin, which facilitates milk ejection.
- Which of the following hormones triggers ovulation?
a) Follicle-stimulating hormone (FSH)
b) Luteinizing hormone (LH)
c) Progesterone
d) Estrogen
Answer: b) Luteinizing hormone (LH)
Explanation:
The LH surge triggers ovulation, causing the mature ovarian follicle to release the egg. LH also promotes the formation of the corpus luteum from the ruptured follicle.
- The cells that produce testosterone in the testes are:
a) Sertoli cells
b) Leydig cells
c) Spermatogonia
d) Granulosa cells
Answer: b) Leydig cells
Explanation:
Leydig cells, located in the interstitial tissue of the testes, are responsible for the production of testosterone, which is essential for spermatogenesis and the development of male secondary sexual characteristics.
- Which of the following is NOT a function of the human placenta?
a) Exchange of nutrients and gases
b) Production of progesterone
c) Elimination of fetal waste
d) Production of sperm
Answer: d) Production of sperm
Explanation:
The placenta functions in nutrient and gas exchange, production of hormones like progesterone and human chorionic gonadotropin (hCG), and elimination of fetal waste, but it is not involved in sperm production, which occurs in the male testes.
- The developing embryo is implanted into the uterus at which stage?
a) Zygote
b) Morula
c) Blastocyst
d) Gastrula
Answer: c) Blastocyst
Explanation:
Implantation occurs when the blastocyst, which is a hollow ball of cells, attaches to and embeds itself into the uterine wall (endometrium). This is a critical step in the establishment of pregnancy.
- Which part of the sperm contains mitochondria?
a) Head
b) Acrosome
c) Middle piece
d) Tail
Answer: c) Middle piece
Explanation:
The middle piece of the sperm contains numerous mitochondria, which generate the energy (ATP) required for sperm motility, enabling the sperm to swim towards the egg for fertilization.
- Which of the following structures produces estrogen in females?
a) Corpus luteum
b) Pituitary gland
c) Graafian follicle
d) Fallopian tube
Answer: c) Graafian follicle
Explanation:
The Graafian follicle, which is a mature ovarian follicle, produces estrogen. Estrogen helps in the proliferation of the endometrium and also regulates the menstrual cycle and female secondary sexual characteristics.
- Which of the following layers forms the fetal part of the placenta?
a) Endometrium
b) Chorion
c) Amnion
d) Myometrium
Answer: b) Chorion
Explanation:
The chorion is the outermost fetal membrane and forms the fetal part of the placenta. It is involved in nutrient and gas exchange between the mother and fetus.
- The hormone detected in pregnancy tests is:
a) Progesterone
b) Estrogen
c) hCG (Human Chorionic Gonadotropin)
d) LH
Answer: c) hCG (Human Chorionic Gonadotropin)
Explanation:
hCG is a hormone produced by the trophoblast cells of the developing embryo shortly after implantation. It is the hormone detected by pregnancy tests and helps maintain the corpus luteum, ensuring the continued production of progesterone during early pregnancy.
- Which structure stores the sperm before ejaculation?
a) Vas deferens
b) Testes
c) Epididymis
d) Seminal vesicles
Answer: c) Epididymis
Explanation:
The epididymis stores mature sperm until ejaculation. It also serves as a site for sperm maturation, where they gain the ability to swim and fertilize an egg.
- Which of the following events marks the beginning of the menstrual phase?
a) Development of the corpus luteum
b) Ovulation
c) Shedding of the endometrium
d) Release of progesterone
Answer: c) Shedding of the endometrium
Explanation:
The menstrual phase begins with the shedding of the endometrium (the inner lining of the uterus) due to a drop in progesterone and estrogen levels, marking the beginning of a new menstrual cycle.
- In which structure does the fertilized egg implant and grow during pregnancy?
a) Ovary
b) Fallopian tube
c) Uterus
d) Vagina
Answer: c) Uterus
Explanation:
The fertilized egg (blastocyst) implants into the endometrium of the uterus, where it continues to grow and develop into an embryo and later a fetus.
- What is the primary function of progesterone during pregnancy?
a) Stimulating uterine contractions
b) Maintaining the uterine lining
c) Promoting lactation
d) Initiating ovulation
Answer: b) Maintaining the uterine lining
Explanation:
Progesterone is crucial for maintaining the uterine lining (endometrium) throughout pregnancy, ensuring a suitable environment for the embryo’s growth and preventing menstruation.
- Which of the following happens after the fusion of the sperm and egg nuclei?
a) Formation of the morula
b) Formation of a diploid zygote
c) Formation of the blastocyst
d) Initiation of organogenesis
Answer: b) Formation of a diploid zygote
Explanation:
Once the sperm and egg nuclei fuse, they form a diploid zygote, which is the first cell of the new organism. This zygote will undergo successive cell divisions and eventually develop into a blastocyst.
- During which part of the menstrual cycle is the endometrium thickest?
a) Menstrual phase
b) Follicular phase
c) Luteal phase
d) Ovulation phase
Answer: c) Luteal phase
Explanation:
The endometrium is thickest during the luteal phase, which occurs after ovulation. The corpus luteum produces progesterone, which stimulates the endometrial glands to secrete nutrients, preparing the uterus for a possible pregnancy.
- Which of the following structures in the male reproductive system provides nourishment to sperm?
a) Prostate gland
b) Seminal vesicles
c) Epididymis
d) Cowper’s gland
Answer: b) Seminal vesicles
Explanation:
The seminal vesicles secrete a fluid rich in fructose and other nutrients, which provides nourishment to sperm and forms the majority of the ejaculatory fluid. This fluid also helps in sperm motility.
- Which hormone is responsible for the onset of labor contractions?
a) Prolactin
b) Oxytocin
c) Estrogen
d) Progesterone
Answer: b) Oxytocin
Explanation:
Oxytocin, produced by the posterior pituitary gland, stimulates powerful uterine contractions during labor. It is often referred to as the “birth hormone” and plays a key role in the delivery process.
- Which of the following layers of the uterus is shed during menstruation?
a) Myometrium
b) Endometrium
c) Perimetrium
d) Epimetrium
Answer: b) Endometrium
Explanation:
The endometrium is the inner lining of the uterus that thickens during the menstrual cycle in preparation for a fertilized egg. If pregnancy does not occur, the endometrium is shed during menstruation.
- Which hormone is primarily responsible for the thickening of the endometrium during the menstrual cycle?
a) Estrogen
b) Progesterone
c) Follicle-stimulating hormone (FSH)
d) Luteinizing hormone (LH)
Answer: a) Estrogen
Explanation:
Estrogen, secreted by the growing ovarian follicles, promotes the thickening of the endometrial lining during the follicular phase of the menstrual cycle. This prepares the uterus for potential implantation of a fertilized egg.
- Which of the following is NOT part of the male reproductive system?
a) Epididymis
b) Vas deferens
c) Seminal vesicle
d) Fallopian tube
Answer: d) Fallopian tube
Explanation:
The fallopian tubes are part of the female reproductive system, where fertilization typically occurs. The male reproductive system includes structures like the epididymis, vas deferens, and seminal vesicles.
- The hormone responsible for maintaining the corpus luteum during early pregnancy is:
a) Progesterone
b) Estrogen
c) Luteinizing hormone (LH)
d) Human chorionic gonadotropin (hCG)
Answer: d) Human chorionic gonadotropin (hCG)
Explanation:
hCG is produced by the developing embryo after implantation. It maintains the corpus luteum, which continues to produce progesterone, supporting the pregnancy until the placenta takes over hormone production.
- Which of the following is the correct sequence of events in the development of a zygote?
a) Blastula → Morula → Gastrula
b) Morula → Blastula → Gastrula
c) Gastrula → Blastula → Morula
d) Morula → Gastrula → Blastula
Answer: b) Morula → Blastula → Gastrula
Explanation:
After fertilization, the zygote undergoes cleavage to form a solid ball of cells called the morula. The morula then develops into a blastula (with a hollow cavity), which further differentiates into a gastrula during gastrulation, where the three germ layers are formed.
- The site of implantation of the blastocyst in the female reproductive system is the:
a) Ovaries
b) Fallopian tube
c) Uterine wall (endometrium)
d) Cervix
Answer: c) Uterine wall (endometrium)
Explanation:
The blastocyst implants into the thickened endometrium of the uterus, where it establishes the placenta and continues its development into an embryo and later a fetus.
- Which of the following is the correct function of the amniotic fluid?
a) To provide nutrients to the fetus
b) To facilitate gas exchange
c) To protect the fetus from physical injury
d) To help in the release of oxytocin
Answer: c) To protect the fetus from physical injury
Explanation:
Amniotic fluid surrounds the developing fetus in the amniotic sac, providing a cushion that protects the fetus from mechanical shocks, helps maintain a stable temperature, and allows for fetal movement.
- Which of the following hormones is primarily responsible for preparing the mammary glands for lactation during pregnancy?
a) Estrogen
b) Progesterone
c) Prolactin
d) Oxytocin
Answer: c) Prolactin
Explanation:
Prolactin is produced by the anterior pituitary gland and plays a key role in stimulating the mammary glands to produce milk. While oxytocin aids in milk ejection, prolactin is responsible for milk production.
- Which of the following is the process by which the mature egg is released from the ovary?
a) Fertilization
b) Ovulation
c) Menstruation
d) Parturition
Answer: b) Ovulation
Explanation:
Ovulation is the release of a mature egg from the ovarian follicle into the fallopian tube, where it may be fertilized by sperm. This typically occurs around the midpoint of the menstrual cycle.
- The process of cleavage in the early stages of embryonic development results in:
a) Increase in the size of cells
b) Increase in the number of cells
c) Formation of germ layers
d) Development of organs
Answer: b) Increase in the number of cells
Explanation:
Cleavage is a series of rapid mitotic cell divisions that increase the number of cells (blastomeres) in the developing embryo without an increase in overall size. This process eventually leads to the formation of the morula and blastula.
- Which of the following events happens first after the fusion of sperm and egg?
a) Formation of the blastocyst
b) Cleavage
c) Gastrulation
d) Implantation
Answer: b) Cleavage
Explanation:
Cleavage begins shortly after the fusion of sperm and egg, resulting in a rapid series of cell divisions. These divisions produce a multicellular structure, which will further develop into a blastocyst.
- Which of the following hormones stimulates the development of secondary sexual characteristics in females?
a) Progesterone
b) Testosterone
c) Estrogen
d) Luteinizing hormone (LH)
Answer: c) Estrogen
Explanation:
Estrogen is responsible for the development of secondary sexual characteristics in females, such as breast development, widening of the hips, and the regulation of the menstrual cycle.
- The process of embedding the blastocyst into the endometrial lining of the uterus is called:
a) Fertilization
b) Implantation
c) Cleavage
d) Gastrulation
Answer: b) Implantation
Explanation:
Implantation is the process by which the blastocyst embeds itself into the endometrium (the lining of the uterus) to establish a pregnancy. It occurs about 6-10 days after fertilization.
- The hormone primarily responsible for the thickening of the endometrial lining after ovulation is:
a) Estrogen
b) Progesterone
c) Follicle-stimulating hormone (FSH)
d) Luteinizing hormone (LH)
Answer: b) Progesterone
Explanation:
After ovulation, the corpus luteum produces progesterone, which prepares the endometrium for potential implantation by thickening it and making it more glandular and vascularized.
- In which part of the male reproductive system does spermatogenesis take place?
a) Epididymis
b) Vas deferens
c) Seminal vesicle
d) Seminiferous tubules
Answer: d) Seminiferous tubules
Explanation:
Spermatogenesis, the process of sperm production, occurs in the seminiferous tubules of the testes. The tubules contain germ cells that undergo division and differentiation to form spermatozoa.
- The structure that helps the sperm penetrate the egg during fertilization is:
a) Flagellum
b) Acrosome
c) Nucleus
d) Mitochondria
Answer: b) Acrosome
Explanation:
The acrosome is a cap-like structure covering the head of the sperm that contains enzymes such as hyaluronidase. These enzymes help break down the outer layers of the egg, allowing the sperm to penetrate the egg and fertilize it.
- Which of the following is the function of the corpus luteum during the menstrual cycle?
a) To release the egg
b) To produce FSH
c) To secrete progesterone
d) To cause menstruation
Answer: c) To secrete progesterone
Explanation:
The corpus luteum is formed from the remnants of the follicle after ovulation and secretes progesterone. This hormone is crucial for maintaining the endometrial lining and supporting early pregnancy.
- Which of the following structures forms the fetal side of the placenta?
a) Amnion
b) Chorion
c) Endometrium
d) Allantois
Answer: b) Chorion
Explanation:
The chorion forms the fetal portion of the placenta, which is involved in nutrient and gas exchange between the mother and fetus. The maternal side of the placenta is derived from the uterine tissues.
- The presence of which hormone in the blood or urine indicates pregnancy?
a) Luteinizing hormone (LH)
b) Progesterone
c) Estrogen
d) Human chorionic gonadotropin (hCG)
Answer: d) Human chorionic gonadotropin (hCG)
Explanation:
hCG is produced by the trophoblast cells of the early embryo after implantation and is detected in pregnancy tests. This hormone supports the corpus luteum, which in turn produces progesterone to maintain the uterine lining.
- Which of the following structures provides nutrients to the developing embryo before the placenta forms?
a) Yolk sac
b) Chorion
c) Amnion
d) Allantois
Answer: a) Yolk sac
Explanation:
The yolk sac provides early nourishment to the embryo before the placenta is fully formed. It is an extra-embryonic membrane that also contributes to the formation of the blood and germ cells.
- Which of the following processes occurs during the luteal phase of the menstrual cycle?
a) Ovulation
b) Formation of the corpus luteum
c) Thickening of the endometrium
d) Shedding of the endometrium
Answer: b) Formation of the corpus luteum
Explanation:
The luteal phase begins after ovulation when the ruptured follicle forms the corpus luteum. This structure secretes progesterone, which thickens the endometrium and prepares it for possible implantation.
- During human development, which stage directly follows fertilization?
a) Gastrulation
b) Morula
c) Cleavage
d) Blastocyst
Answer: c) Cleavage
Explanation:
Cleavage occurs immediately after fertilization and involves a series of rapid mitotic divisions of the zygote without an increase in size, eventually leading to the formation of a morula and then a blastocyst.
- The hormone that triggers the final maturation and release of the egg from the ovarian follicle is:
a) Follicle-stimulating hormone (FSH)
b) Estrogen
c) Luteinizing hormone (LH)
d) Progesterone
Answer: c) Luteinizing hormone (LH)
Explanation:
LH triggers ovulation by causing the mature ovarian follicle to rupture and release the egg. This surge in LH is also responsible for initiating the formation of the corpus luteum.
- The structure in the male reproductive system that serves as the site of sperm storage and maturation is the:
a) Seminal vesicle
b) Epididymis
c) Vas deferens
d) Prostate gland
Answer: b) Epididymis
Explanation:
The epididymis is where sperm are stored and mature after they are produced in the seminiferous tubules of the testes. Sperm gain motility and the ability to fertilize an egg while in the epididymis.
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