Male reproductive system Questions in English

(B) Based on the anatomical structure of the mammalian testis:
$A$ represents the Tunica vaginalis,which is the outer serous covering.
$B$ represents the Rete testis,a network of tubules in the mediastinum testis.
$C$ represents the Cauda epididymis,the posterior part of the epididymis.
$D$ represents the Vas deferens,the duct that transports sperm.
$E$ represents the Tunica albuginea,the tough fibrous capsule surrounding the testis.
$F$ represents the Caput epididymis,the anterior head region of the epididymis.
Therefore,the correct labeling is $A-$Tunica vaginalis,$B-$Rete testis,$C-$Cauda epididymis,$D-$Vas deferens,$E-$Tunica albuginea,$F-$Caput epididymis.

(A) The bulbourethral glands are a pair of small glands located on either side of the $Urethra$ in males.
They are also known as $Cowper's$ glands.
These glands secrete an $Alkaline$ fluid and $Mucous$ which helps in the lubrication of the penis during sexual arousal.
Therefore, $A = Cowper's$, $B = Urethra$, $C = Alkaline$, and $D = Mucous$.

(C) Primary sex organs (testes in males and ovaries in females) are responsible for the production of gametes and the secretion of sex hormones. Secondary sex organs,such as the vasa deferentia,epididymis,and fallopian tubes,are involved in the conduction and storage of gametes. Therefore,the conduction of gametes is a function of secondary sex organs,not primary sex organs.

(B) The testes are located outside the abdominal cavity within the scrotum because the process of spermatogenesis requires a temperature approximately $2.5^{\circ}C$ lower than the normal internal body temperature. This lower temperature is essential for the viability and proper development of sperm cells.

(C) According to the $NCERT$ textbook, each testis in a human male contains approximately $250$ compartments known as testicular lobules.
Each of these testicular lobules contains $1$ to $3$ highly coiled seminiferous tubules.
These seminiferous tubules are the sites where spermatogenesis (production of sperms) occurs.
Therefore, the correct values for $A$ and $B$ are $250$ and $1-3$ respectively, which corresponds to option $C$.

(D) Leydig cells are also known as interstitial cells because they are located in the interstitial spaces between the seminiferous tubules.
These cells synthesize and secrete testicular hormones,which are collectively known as androgens (primarily testosterone).
Since these cells release hormones directly into the blood,they constitute the endocrine part of the testis.

(B) The path of sperm is as follows:
Seminiferous tubules $\rightarrow$ Rete testis $\rightarrow$ Vasa efferentia $\rightarrow$ Epididymis $\rightarrow$ Vas deferens.
The vas deferens dilates to form an ampulla,which receives the duct from the seminal vesicle to form the ejaculatory duct.
This ejaculatory duct then opens into the urethra.

(B) The secretion of the seminal vesicles contains fructose,inositol,prostaglandins,and clotting proteins. Fructose serves as the primary energy source for sperm cells.

(D) The male accessory glands consist of paired seminal vesicles,a single prostate gland,and paired bulbourethral glands (also known as Cowper's glands). These glands secrete fluids that form the seminal plasma,which is rich in fructose,calcium,and certain enzymes.

(A) The inner lining of each seminiferous tubule consists of two types of cells: male germ cells (spermatogonia) and Sertoli cells.
Male germ cells undergo meiotic divisions finally leading to sperm formation.
Sertoli cells provide nutrition to the germ cells.
Leydig cells (interstitial cells) are located outside the seminiferous tubules in the interstitial spaces and synthesize and secrete testicular hormones called androgens.

(B) The male sex accessory ducts include the rete testis,vasa efferentia,epididymis,and vas deferens.
These ducts are responsible for the transport and storage of sperms produced in the seminiferous tubules.

(C) The correct pathway of sperm transport in the male reproductive system is as follows:
$1$. Sperms are produced in the $Seminiferous \text{ } tubules$.
$2$. They move into the $Rete \text{ } testis$.
$3$. From the $Rete \text{ } testis$, they pass through the $Vasa \text{ } efferentia$.
$4$. They then enter the $Epididymis$ for maturation and storage.
$5$. From the $Epididymis$, they travel through the $Vas \text{ } deferens$.
$6$. The $Vas \text{ } deferens$ joins with the duct from the seminal vesicle to form the $Ejaculatory \text{ } duct$.
$7$. Finally, the $Ejaculatory \text{ } duct$ opens into the $Urethra$.

(C) In the human male reproductive system,the seminal vesicles (labeled as $B$) contribute about $60-70\%$ of the total volume of semen.
$A$ represents the vas deferens.
$C$ represents the prostate gland.
$D$ represents the bulbourethral gland.
Therefore,the seminal vesicles $(B)$ contribute the maximum portion of semen.

(B) $GnRH$ (Gonadotropin-releasing hormone) is a hypothalamic hormone that acts on the anterior pituitary to stimulate the secretion of gonadotropins,which are $LH$ and $FSH$.
$LH$ (Luteinizing hormone) acts on the Leydig cells and stimulates the synthesis and secretion of androgens.
$FSH$ (Follicle-stimulating hormone) acts on the Sertoli cells and stimulates the secretion of some factors which help in the process of spermiogenesis.
Therefore,$A = GnRH$,$B = LH$,$C = FSH$,and $D = Androgens$.

(A) Spermatogenesis,the process of sperm formation,requires a temperature that is $2 - 2.5^{\circ}C$ lower than the normal internal body temperature.
If the testes fail to descend into the scrotum (a condition known as cryptorchidism),they remain inside the abdominal cavity where the temperature is too high for effective spermatogenesis.
Consequently,this leads to the production of non-viable sperm or a complete lack of sperm production,resulting in sterility in men.
Therefore,both the Assertion and the Reason are correct,and the Reason provides the correct explanation for the Assertion.

(A) The male urethra is approximately $20 \; cm$ long,whereas the female urethra is much shorter,measuring about $2-4 \; cm$.
In males,the urethra serves as a common pathway for both the urinary and reproductive systems,transporting both urine and semen.
In females,the genital tract and the urinary tract have separate openings.
Therefore,the Reason correctly explains why the male urethra is longer and structurally different from the female urethra.

(C) The Assertion is correct because Leydig cells (interstitial cells) are responsible for the synthesis and secretion of androgens,primarily testosterone.
The Reason is incorrect because Leydig cells are located in the interstitial spaces outside the seminiferous tubules,not between the Sertoli cells. Sertoli cells are located inside the seminiferous tubules.

(A) The seminal plasma is secreted by the male accessory glands (seminal vesicles,prostate gland,and bulbourethral glands).
It is rich in fructose,calcium,and certain enzymes.
Fructose is a monosaccharide sugar that provides the primary energy source for the motility of sperms as they travel through the female genital tract.
Therefore,the Reason correctly explains why the presence of fructose in seminal plasma is significant.

(A) The scrotum maintains the temperature of the testes $2-2.5^{\circ}C$ lower than the normal internal body temperature,which is necessary for spermatogenesis.
This temperature regulation is achieved by the contraction and relaxation of the dartos and cremaster muscles.
The dartos muscle is present in the wall of the scrotum,and its contraction causes the scrotal skin to wrinkle,thereby reducing the surface area to conserve heat.
The cremaster muscle helps in pulling the testes closer to or further from the body cavity to regulate temperature.
Since both the assertion and the reason are scientifically accurate and the reason explains the mechanism behind the temperature regulation mentioned in the assertion,the correct option is $A$.

(D) Leydig cells,also known as interstitial cells,are located in the interstitial spaces outside the seminiferous tubules in the testis.
These cells synthesize and secrete testicular hormones called androgens,primarily testosterone.
Therefore,all the given statements are correct.

(A) The correct pathway of sperm transport in the male reproductive system is as follows:
$1$. Sperm are produced in the $\text{Seminiferous tubules}$.
$2$. They move into the $\text{Rete testis}$.
$3$. From there, they pass through the $\text{Vasa efferentia}$.
$4$. They then enter the $\text{Epididymis}$ for maturation and storage.
$5$. They travel through the $\text{Vas deferens}$.
$6$. They enter the $\text{Ejaculatory duct}$ (formed by the duct of the seminal vesicle and vas deferens).
$7$. Finally, they are released through the $\text{Urethra}$.

(C) In the standard diagram of the human male reproductive system,the ejaculatory duct is formed by the union of the duct from the seminal vesicle and the vas deferens. It passes through the prostate gland and opens into the urethra. Based on standard anatomical labeling in $NCERT$ diagrams,the structure typically labeled as the ejaculatory duct is represented by $R$.

(C) The bulbourethral glands (also known as Cowper's glands) are a pair of pea-sized exocrine glands located on the sides of the urethra just below the prostate gland in the male reproductive system.
These glands secrete a clear,alkaline,mucus-like fluid into the urethra.
This secretion serves two primary functions: it neutralizes the acidity of the urine remaining in the urethra and acts as a lubricant for the penis during sexual intercourse.

(A) The testes are situated outside the abdominal cavity within a pouch called the scrotum.
The scrotum helps in maintaining the low temperature of the testes,which is necessary for spermatogenesis.
The temperature of the testes is maintained at $2-2.5^{\circ} C$ lower than the normal internal body temperature.

(B) According to the $NCERT$ textbook,the testes are situated outside the abdominal cavity within a pouch called the scrotum. In adults,each testis is oval in shape,with a length of about $4$ to $5$ $cm$ and a width of about $2$ to $3$ $cm$. The testes are covered by a dense covering. Each testis has about $250$ compartments called testicular lobules. Comparing these facts with the given options,option $B$ states the dimensions as $2$ to $3$ $cm$ in length and $4$ to $5$ $cm$ in width,which is the reverse of the actual anatomical dimensions ($4-5$ $cm$ length and $2-3$ $cm$ width). Therefore,option $B$ is incorrect.

(D) The interstitial cells,also known as Leydig cells,are located in the interstitial spaces outside the seminiferous tubules within the testes.
These cells synthesize and secrete testicular hormones called androgens,primarily testosterone.
Therefore,the correct location is outside the seminiferous tubules and the function is the secretion of androgens.

(C) The vas deferens emerges from the epididymis and enters the abdominal cavity.
It loops over the urinary bladder.
The duct from the seminal vesicle joins with the vas deferens to form the ejaculatory duct.
This duct stores and transports sperm from the testes to the outside through the urethra.

(B) The male reproductive system consists of a pair of testes,accessory ducts,glands,and external genitalia.
The external genitalia of the male is the penis.
It is a copulatory organ made up of special tissue that helps in the erection of the penis to facilitate insemination.
The seminal vesicle is an accessory gland,and the clitoris is a part of the female external genitalia.

(B) The human male reproductive system includes the penis, which is the external genitalia. The penis is composed of special tissue that helps in erection to facilitate insemination. The enlarged end of the penis is covered by a loose fold of skin called the foreskin (prepuce) and is known as the $Glans penis$.

(B) The seminal plasma is the fluid component of semen,which is secreted by the accessory glands,specifically the seminal vesicles,prostate gland,and bulbourethral glands.
Seminal plasma is rich in fructose,calcium,and certain enzymes.
Fructose serves as the primary energy source for the sperm cells,while calcium and various enzymes help in the motility and survival of the sperm within the female reproductive tract.
Therefore,the correct composition includes fructose,calcium,and certain enzymes.

(A) The bulbourethral glands (also known as Cowper's glands) are a pair of pea-sized exocrine glands located along the sides of the urethra just below the prostate gland in the male reproductive system.
Their primary function is to secrete a clear,alkaline fluid into the urethra.
This secretion serves two main purposes: it neutralizes the acidic environment of the urethra caused by urine,and it acts as a lubricant for the penis during sexual intercourse.

(B) The diagram typically shows a circular structure lined with germinal epithelium containing spermatogonia, primary spermatocytes, secondary spermatocytes, spermatids, and spermatozoa, with Sertoli cells interspersed. This characteristic structure is the cross-section of a $seminiferous \text{ } tubule$ found in the testes. The $seminiferous \text{ } tubules$ are the sites of spermatogenesis.

(A) Semen is composed of sperm and seminal plasma.
Seminal plasma is the fluid secreted by the accessory glands (seminal vesicles,prostate gland,and bulbourethral glands) along with the sperm.
Therefore,the correct composition is: Semen $=$ Seminal plasma $+$ Sperm.

(C) The testes are composed of seminiferous tubules where sperm production occurs.
Outside these tubules lies a region known as the interstitial space.
This space contains small blood vessels,Leydig cells (interstitial cells),and immunologically competent cells.
Leydig cells are responsible for the synthesis and secretion of testicular hormones called androgens,primarily testosterone.

(C) The seminiferous tubules are the structural and functional units of the testes where spermatogenesis occurs.
Each seminiferous tubule is lined on its inside by two types of cells:
$1$. Male germ cells (Spermatogonia): These undergo meiotic divisions finally leading to sperm formation.
$2$. Sertoli cells: These are also known as nurse cells,which provide nutrition to the developing germ cells.
Leydig cells (interstitial cells) are present in the interstitial spaces outside the seminiferous tubules,not inside them.
Therefore,the correct option is $C$.

(D) The correct pathway of sperm transport in the male reproductive system is as follows:
$1$. Seminiferous tubules produce sperm.
$2$. Sperm move into the Tubuli recti $(A)$.
$3$. From there,they enter the Rete testis.
$4$. Then,they pass through the Vasa efferentia $(B)$.
$5$. They are stored and matured in the Epididymis.
$6$. Sperm then travel through the Vas deferens $(C)$.
$7$. The Vas deferens joins with the duct of the seminal vesicle to form the Ejaculatory duct $(D)$.
$8$. Finally,the sperm enter the Urethra.
Therefore,the correct sequence is $A \rightarrow$ Tubuli recti,$B \rightarrow$ Vasa efferentia,$C \rightarrow$ Vas deferens,$D \rightarrow$ Ejaculatory duct.

(A) The testes are oval-shaped organs located outside the abdominal cavity within a pouch called the scrotum.
Each testis has a length of approximately $4-5 \ cm$ and a width of approximately $2-3 \ cm$.
The scrotum helps in maintaining the low temperature of the testes ($2-2.5^{\circ}C$ lower than the normal internal body temperature),which is necessary for spermatogenesis.

(C) The correct answer is $C$.
In the human male reproductive system,each testis is divided into about $250$ compartments known as testicular lobules.
The rete testis is a network of tubules located within the testis that receives sperm from the seminiferous tubules,not the compartments themselves.
Therefore,the statement that each testis has about $250$ compartments called rete testis is incorrect.

(B) The male accessory glands include paired seminal vesicles,a single prostate gland,and paired bulbourethral glands.
Seminal vesicles are paired structures.
Bulbourethral glands (also known as Cowper's glands) are also paired.
The prostate gland is a single,unpaired gland that surrounds the urethra.
Therefore,the correct answer is the prostate gland.

(D) Statement-$I$ is correct because the scrotum is a pouch of skin that holds the testes outside the abdominal cavity,which helps in maintaining the temperature of the testes $2-2.5^{\circ}C$ lower than the normal internal body temperature.
Statement-$II$ is also correct because this lower temperature is essential for spermatogenesis,the process of sperm production.
Therefore,both statements are correct.

(D) In the human male reproductive system,the $vasa$ $efferentia$ are ductules that lead from the $rete$ $testis$ to the $epididymis$.
They are responsible for transporting sperm from the $testes$ to the $epididymis$ for maturation and storage.
If the $vasa$ $efferentia$ are blocked,the transport of sperm from the $testes$ to the $epididymis$ will be obstructed.

(C) The seminiferous tubules are the structural and functional units of the testes.
Each seminiferous tubule is lined on its inside by two types of cells: male germ cells (spermatogonia) and Sertoli cells.
Spermatogonia undergo meiotic divisions to produce sperm,while Sertoli cells provide nutrition to the germ cells.
Leydig cells (interstitial cells) are located in the interstitial spaces outside the seminiferous tubules,not inside them.
Each testis contains about $250$ testicular lobules,and each lobule contains $1$ to $3$ highly coiled seminiferous tubules,not $250$ tubules per lobule.

(C) The process of spermatogenesis (sperm production) takes place within the seminiferous tubules of the testes.
Inside each seminiferous tubule,the germinal epithelium is composed of two types of cells: spermatogonia (male germ cells) and Sertoli cells (nurse cells).
Spermatogonia undergo meiotic divisions to produce spermatozoa,while Sertoli cells provide nutrition to the developing germ cells.
Since the presence of these specific cells is the structural basis for sperm production,the reason correctly explains the assertion.

(A) The pathway of sperm transport from the seminiferous tubules to the exterior is as follows:
$1$. Seminiferous tubules
$2$. Rete testis
$3$. Vasa efferentia
$4$. Epididymis
$5$. Vas deferens (Ductus deferens)
$6$. Ejaculatory duct
$7$. Urethra
$8$. Urethral meatus
While the seminal vesicle contributes fluid to the semen,the sperm cells themselves do not pass through the lumen of the seminal vesicle. Therefore,the seminal vesicle is the correct answer.

(A) The correct matching is as follows:
$i$. Prepuce: It is a loose fold of skin that covers the glans penis $(c)$.
$ii$. Penis: It is the male copulatory organ $(d)$.
$iii$. Testis: It is the primary male reproductive gonad responsible for producing sperm and hormones $(b)$.
$iv$. Gubernaculum: It is a fibromuscular band that helps in the descent and retention of the testis in the scrotum $(a)$.
Therefore,the correct sequence is $i-c, ii-d, iii-b, iv-a$.

(D) Semen is composed of secretions from the seminal vesicles,prostate gland,and bulbourethral glands.
These secretions contain fructose (an energy source for sperm),prostaglandins (which stimulate uterine contractions),and calcium and bicarbonates (which help neutralize the acidic environment of the female reproductive tract).
Fertilizin is a glycoprotein present on the surface of the egg (ovum),not in the semen.
It acts as a receptor for sperm-binding proteins (antifertilizin) during the process of fertilization.

(D) Based on the diagram of the $T.S.$ of the testis:
$A$ represents the Germinal epithelium (spermatogonia),which undergoes spermatogenesis to produce spermatozoa.
$B$ represents the Sertoli cells,which provide nutrition to the developing sperms.
$C$ represents the Interstitial cells (Leydig cells),which are responsible for the production of testosterone,the hormone responsible for the development of male secondary sexual characters.
$D$ represents the spermatozoa,which are haploid male gametes.
Evaluating the given statements:
- Statement $A$: Correct,as germinal epithelium cells undergo spermatogenesis.
- Statement $B$: Incorrect,as Sertoli cells provide nutrition,while Leydig cells $(C)$ produce testosterone.
- Statement $C$: Incorrect,as sperms are attached to Sertoli cells $(B)$,not Leydig cells $(C)$.
- Statement $D$: Correct,as $D$ represents the haploid male gamete (spermatozoa).
Therefore,statements $A$ and $D$ are correct.

(C) The correct answer is $C$. Sustentacular cells, also known as $Sertoli$ cells, are large, pyramidal-shaped cells found within the seminiferous tubules of the testes. They provide nourishment to developing spermatozoa. They are not small cuboidal cells lining the urinogenital duct. The other options are correctly matched: $Scrotum$ is the pouch containing the testes, the $Inguinal$ $canal$ is the passage through which testes descend into the scrotum, and $Interstitial$ cells ($Leydig$ cells) are responsible for the secretion of androgens.

(A) In human males, the $Urethra$ serves as a common pathway for both urine and semen.
It originates from the urinary bladder and extends through the penis to its external opening called the urethral meatus.
Because it transports both urine (from the urinary system) and semen (from the reproductive system), it is referred to as the urinogenital organ.
$Epididymis$ is involved in sperm maturation, $Ureter$ carries urine from the kidney to the bladder, and the $Urinary bladder$ stores urine.

(B) $Statement-I$ is incorrect because the prostate gland is a large single gland, not a paired gland. It is located underneath the urinary bladder.
$Statement-II$ is correct because the prostate gland secretes a milky white, slightly acidic fluid into the urethra, which contributes to the formation of semen.