1
CHAPTER
Human Reproduction
Year Wise Number of Questions Analysis (2023-2014)
5
4
Number of Questions
3
2
1
0
2023 2022 2021 2020 2020 2019 2018 2017 2016 II 2016 I 2015 2015 Re 2014
Covid
Years
Topicwise Number of Questions Analysis (2023-2014)
4 1 8 10 8 8 2
10
9
Pregnancy and Embryonic development
8
7
Fertilisation and Implantation
Number of Questions
Female Reproductive System
6
Male Reproductive System
Parturition and Lactation
5
4
Menstrual Cycle
Gametogenesis
3
2
1
Topics
, Table: Primary and secondary sex organs in males and female
INTRODUCTION
Primary Accessory or
Reproduction means the ability to produce individuals of Sex Sex Secondary Sex Organ external Sex
the same species. Humans are sexually reproducing and Organ character
viviparous. Male Testis Prostate gland, seminal Low-pitch voice,
To continue its own race, an organism produces offsprings vesicles, bulbourethral beard, broad
like its own by the process of reproduction. glands, vas deferens, shoulder, narrow
Reproductive Events in Humans (Occur after Puberty) epididymis, penis. hips.
(i) Gametogenesis: Formation of gametes, i.e., sperms in Female Ovary Fallopian tubes, High-pitch voice,
males and ovum in females. uterus, cervix, vagina, smooth face, narrow
(ii) Insemination: Transfer of sperms into the female genital mammary glands. shoulder, broad hips.
tract.
(iii) Fertilisation: Fusion of male and female gametes leading MALE REPRODUCTIVE SYSTEM
to the formation of zygote.
(iv) Implantation: Formation and development of blastocyst The male reproductive system is located in the pelvis region.
and attachment of blastocyst to the 1 * for It includes a pair of testes alongwith 3 , glands and
nourishment. the external genitalia.
(v) Gestation: Embryonic development. Male sex accessory ducts include:
(vi) Parturition: Delivery of the foetus. (a) Rete testis (b) Vasa efferentia
(c) Epididymis (d) Vas deferens
Need to Know 3D Model
Scan this QR code to understand Human Male
P There are remarkable differences between the Reproductive System through 3D model. To
reproductive events in the male and in the female. learn more download the Physics Wallah App.
P Sperm formation continues even in old men.
P Formation of ovum ceases in women around the age of Puberty
fifty years. The age of sexual maturity is called puberty.
Accessory sexual characters first appear in puberty.
Primary Sex Organs Puberty occurs in boys at the age of 12-15 years.
The formation of gametes takes place in the reproductive Secondary Sexual Characters in Males:
organs. Enlargement of the testes, spermatogenesis begins.
Essential organs which are responsible for the formation of
Accessory sexual organ like penis, prostate gland, seminal
the gametes (sperm and egg), and several steroid hormones.
vesicles and epididymis grow in mass.
The male gamete is the spermatozoa (sperms).
Appearance of beard, moustache, axillary, pubic & chest hair.
Male hormones are testosterone and inhibin.
Skeletal system grows in length and muscular system grows
The female gamete is the ovum.
Female hormones are progesterone and estrogen.
in bulk & strength.
Ureter Urinary
bladder
Key Note Vas deferens Seminal vesicle
4
Primary sex organs are generally known as gonads because
Bulbourethral
they produce reproductive gametes containing heritable DNA. gland
Epididymis
Urethra
Vasa efferentia
Rete testis
Secondary Sex Organs
They are important for reproduction but do not produce Testicular lobules Testis
2 .
Foreskin
They form the passage for the gametes to help the union of Glans penis
male and female gametes. Fig. 1: Diagrammatic view of male reproductive system
1 * “NCERT Focused Fill-ins” is an exercise with blanks in textbook passages that students fill in to test their NCERT-based knowledge and grasp over NCERT Textbook.
P NEET (XII) Module-1 ZOOLOGY
2 W
,Scrotum Interstitial cells or Leydig cells synthesise and secrete
Both testes are situated outside the abdominal cavity testicular hormones called androgens.
within a pouch called scrotum. Scrotum is connected to the
abdominal cavity through a passage termed as inguinal-canal.
Through this canal the testis descend down from abdominal
cavity into the scrotal sacs at the time of birth.
When the testes does not descend to reach the scrotum instead
remain in abdominal cavity at the time of birth this condition
is called undescended testes or cryptorchidism.
Testes (Singular-Testis)
Testes are the primary male sex organs.
The testis is covered by a dense covering. Fig. 3: Diagrammatic sectional view of male pelvis showing
In adults, each testis is oval in shape, with a length of about reproductive system
4 to 5 cm and a width of about 2 to 3 cm.
Each testis has about 250 compartments called testicular
lobules.
Each lobule contains one to three highly coiled 5 in
which sperms are produced.
Each seminiferous tubules, lined on its inside by two kinds
of cells; male germ cells (spermatogonia) and Sertoli cells.
The spermatogonia undergo meiotic divisions finally leading to
sperm formation.
Sertoli cells/sustentacular cells (supporting cells) are Fig. 4: Diagrammatic sectional view of seminiferous tubule
located in seminiferous tubules which nourish the germ
cells. EXTENDED LEARNING
P Orchiopexy: When the undescended testes are brought
into scrotal sac by surgical process during childhood this
process called as orchiopexy.
P Castration: It is generally the surgical removal of the testes
that leads to decrease in the level of testosterone. It is used
to convert an aggressive bull to a docile ox.
Male Accessory Ducts
Rete Testis
All the seminiferous tubules in each testis open into a network
called rete testis that are responsible for the transport of
sperm cells from the testicle to the epididymis.
Vasa Efferentia
These are a group of 12 to 20 highly convoluted tubules that
lead from the 7 to the vas deferens.
Epididymis
Several ducts called vasa efferentia arise from rete testis and
Fig. 2: Section of a testis showing seminiferous tubules
open into epididymis.
and other components.
Epididymis is an irregular, narrow and highly convoluted
3D Model tubule located along the 8 of each testis.
Scan this QR code to understand the structure
of Testes through 3D model. To learn more Need to Know
download the Physics Wallah App
Interstitial spaces are the regions outside the seminiferous Normal sperm production requires a temperature about 2-2.5°C
tubules which contain small 6 , interstitial cells below core body temperature. This lowered temperature is
(leydig cells) and immunocompetent cells. maintained within the scrotum because it is outside the pelvic cavity.
Human Reproduction 3
, 2. Prostate Gland: Prostate is situated at the origin of the
Key Note
urethra. It contains prostatic fluid (slightly acidic) and covered
P Sperms achieve maturity and motility in epididymis. by a capsule.
P Epididymis can temporarily stores the sperms. The secretions involve calcium ions and proteolytic enzymes,
e.g., fibrinolysin.
Vas Deferens Prostate gland is an unpaired organ.
Vas deferens or sperm duct arises from 9 , ascends to 3. Cowper’s Glands: These are also known as bulbourethral
the abdomen, loops over the urinary bladder and receive a duct 11
glands, situated beneath the and behind the
from seminal vesicle and opens into urethra as ejaculatory
urethra.
duct.
Cowper’s gland secretion acts as a 12 for the glans
Key Note penis. It also neutralises traces of acidic urine in urethra.
Bulbourethral gland is also paired organ like seminal vesicles.
Vas deferens store and transport the sperms from the
epididymis towards the urethra. Semen
Semen = Sperms + Seminal fluid
Urethra
Urethra is a thin-walled muscular duct and it is a common Volume = 3 to 4 ml.
passage for both urine and semen in males hence, called pH = 7.2 – 7.7.
urinogenital duct. Normal sperm count = 20 – 120 million/ml.
The urethra originates from the urinary bladder and extends Semen is a greyish whitish fluid released during ejaculation
through the penis to its external opening called 10 .
which contains a mixture of spermatozoa (sperms) that are
Male External Genitalia produced in the testes and mixed with secretions from the
Penis male accessory sex glands (seminal fluid), including the
The penis is the male external genitalia. prostate gland, seminal vesicles, bulbourethral gland.
It is made up of special tissue that helps in erection of the 13 is found in seminal fluid, it acts as fuel to sperm.
penis to facilitate insemination. Fibrinogen, prostaglandin, citrate, inositol and several proteins
The enlarged end of penis called the glans penis is covered are also present in semen.
by a loose fold of skin called foreskin or prepuce. Ejaculation of semen is controlled by sympathetic nervous
EXTENDED LEARNING system.
P Wolffian duct: In males, wolffian duct or mesonephric
duct leads to the formation of epididymis, vas deferens and
seminal vesicle. Need to Know
P Erection of penis is regulated by parasympathetic nervous
system that causes vasodilation in smooth muscles of P Fluid secreted by the seminal vesicles normally constitutes
erectile tissue of penis by release of nitric oxide.
about 60% of the volume of semen.
Male Accessory Glands P Prostatic Fluid: Prostatic secretion forms about 30% of
1. Seminal Vesicles: Seminal vesicles are situated at the the volume of semen.
junction of vas deferens and prostate gland. They are narrow, It is slightly acidic, pH 6.5 due to the presence of
long pouches with muscular tissue on their wall. Seminal
citric acid.
vesicles are paired organs.
Secretion of seminal vesicle has an alkaline pH and is rich in
Prostatic secretion contains substances important for
fructose, ascorbic acid, prostaglandins and various enzymes. sperm mobility.
Cowper’s glands open into urethra before entering
Key Note into penis.
Cowper’s Fluid: Secretion of cowper’s gland is
The fructose, present in the seminal fluid, is the source of slightly alkaline and is produced during sexual
energy for the spermatozoa. stimulation.
P NEET (XII) Module-1 ZOOLOGY
4 W
CHAPTER
Human Reproduction
Year Wise Number of Questions Analysis (2023-2014)
5
4
Number of Questions
3
2
1
0
2023 2022 2021 2020 2020 2019 2018 2017 2016 II 2016 I 2015 2015 Re 2014
Covid
Years
Topicwise Number of Questions Analysis (2023-2014)
4 1 8 10 8 8 2
10
9
Pregnancy and Embryonic development
8
7
Fertilisation and Implantation
Number of Questions
Female Reproductive System
6
Male Reproductive System
Parturition and Lactation
5
4
Menstrual Cycle
Gametogenesis
3
2
1
Topics
, Table: Primary and secondary sex organs in males and female
INTRODUCTION
Primary Accessory or
Reproduction means the ability to produce individuals of Sex Sex Secondary Sex Organ external Sex
the same species. Humans are sexually reproducing and Organ character
viviparous. Male Testis Prostate gland, seminal Low-pitch voice,
To continue its own race, an organism produces offsprings vesicles, bulbourethral beard, broad
like its own by the process of reproduction. glands, vas deferens, shoulder, narrow
Reproductive Events in Humans (Occur after Puberty) epididymis, penis. hips.
(i) Gametogenesis: Formation of gametes, i.e., sperms in Female Ovary Fallopian tubes, High-pitch voice,
males and ovum in females. uterus, cervix, vagina, smooth face, narrow
(ii) Insemination: Transfer of sperms into the female genital mammary glands. shoulder, broad hips.
tract.
(iii) Fertilisation: Fusion of male and female gametes leading MALE REPRODUCTIVE SYSTEM
to the formation of zygote.
(iv) Implantation: Formation and development of blastocyst The male reproductive system is located in the pelvis region.
and attachment of blastocyst to the 1 * for It includes a pair of testes alongwith 3 , glands and
nourishment. the external genitalia.
(v) Gestation: Embryonic development. Male sex accessory ducts include:
(vi) Parturition: Delivery of the foetus. (a) Rete testis (b) Vasa efferentia
(c) Epididymis (d) Vas deferens
Need to Know 3D Model
Scan this QR code to understand Human Male
P There are remarkable differences between the Reproductive System through 3D model. To
reproductive events in the male and in the female. learn more download the Physics Wallah App.
P Sperm formation continues even in old men.
P Formation of ovum ceases in women around the age of Puberty
fifty years. The age of sexual maturity is called puberty.
Accessory sexual characters first appear in puberty.
Primary Sex Organs Puberty occurs in boys at the age of 12-15 years.
The formation of gametes takes place in the reproductive Secondary Sexual Characters in Males:
organs. Enlargement of the testes, spermatogenesis begins.
Essential organs which are responsible for the formation of
Accessory sexual organ like penis, prostate gland, seminal
the gametes (sperm and egg), and several steroid hormones.
vesicles and epididymis grow in mass.
The male gamete is the spermatozoa (sperms).
Appearance of beard, moustache, axillary, pubic & chest hair.
Male hormones are testosterone and inhibin.
Skeletal system grows in length and muscular system grows
The female gamete is the ovum.
Female hormones are progesterone and estrogen.
in bulk & strength.
Ureter Urinary
bladder
Key Note Vas deferens Seminal vesicle
4
Primary sex organs are generally known as gonads because
Bulbourethral
they produce reproductive gametes containing heritable DNA. gland
Epididymis
Urethra
Vasa efferentia
Rete testis
Secondary Sex Organs
They are important for reproduction but do not produce Testicular lobules Testis
2 .
Foreskin
They form the passage for the gametes to help the union of Glans penis
male and female gametes. Fig. 1: Diagrammatic view of male reproductive system
1 * “NCERT Focused Fill-ins” is an exercise with blanks in textbook passages that students fill in to test their NCERT-based knowledge and grasp over NCERT Textbook.
P NEET (XII) Module-1 ZOOLOGY
2 W
,Scrotum Interstitial cells or Leydig cells synthesise and secrete
Both testes are situated outside the abdominal cavity testicular hormones called androgens.
within a pouch called scrotum. Scrotum is connected to the
abdominal cavity through a passage termed as inguinal-canal.
Through this canal the testis descend down from abdominal
cavity into the scrotal sacs at the time of birth.
When the testes does not descend to reach the scrotum instead
remain in abdominal cavity at the time of birth this condition
is called undescended testes or cryptorchidism.
Testes (Singular-Testis)
Testes are the primary male sex organs.
The testis is covered by a dense covering. Fig. 3: Diagrammatic sectional view of male pelvis showing
In adults, each testis is oval in shape, with a length of about reproductive system
4 to 5 cm and a width of about 2 to 3 cm.
Each testis has about 250 compartments called testicular
lobules.
Each lobule contains one to three highly coiled 5 in
which sperms are produced.
Each seminiferous tubules, lined on its inside by two kinds
of cells; male germ cells (spermatogonia) and Sertoli cells.
The spermatogonia undergo meiotic divisions finally leading to
sperm formation.
Sertoli cells/sustentacular cells (supporting cells) are Fig. 4: Diagrammatic sectional view of seminiferous tubule
located in seminiferous tubules which nourish the germ
cells. EXTENDED LEARNING
P Orchiopexy: When the undescended testes are brought
into scrotal sac by surgical process during childhood this
process called as orchiopexy.
P Castration: It is generally the surgical removal of the testes
that leads to decrease in the level of testosterone. It is used
to convert an aggressive bull to a docile ox.
Male Accessory Ducts
Rete Testis
All the seminiferous tubules in each testis open into a network
called rete testis that are responsible for the transport of
sperm cells from the testicle to the epididymis.
Vasa Efferentia
These are a group of 12 to 20 highly convoluted tubules that
lead from the 7 to the vas deferens.
Epididymis
Several ducts called vasa efferentia arise from rete testis and
Fig. 2: Section of a testis showing seminiferous tubules
open into epididymis.
and other components.
Epididymis is an irregular, narrow and highly convoluted
3D Model tubule located along the 8 of each testis.
Scan this QR code to understand the structure
of Testes through 3D model. To learn more Need to Know
download the Physics Wallah App
Interstitial spaces are the regions outside the seminiferous Normal sperm production requires a temperature about 2-2.5°C
tubules which contain small 6 , interstitial cells below core body temperature. This lowered temperature is
(leydig cells) and immunocompetent cells. maintained within the scrotum because it is outside the pelvic cavity.
Human Reproduction 3
, 2. Prostate Gland: Prostate is situated at the origin of the
Key Note
urethra. It contains prostatic fluid (slightly acidic) and covered
P Sperms achieve maturity and motility in epididymis. by a capsule.
P Epididymis can temporarily stores the sperms. The secretions involve calcium ions and proteolytic enzymes,
e.g., fibrinolysin.
Vas Deferens Prostate gland is an unpaired organ.
Vas deferens or sperm duct arises from 9 , ascends to 3. Cowper’s Glands: These are also known as bulbourethral
the abdomen, loops over the urinary bladder and receive a duct 11
glands, situated beneath the and behind the
from seminal vesicle and opens into urethra as ejaculatory
urethra.
duct.
Cowper’s gland secretion acts as a 12 for the glans
Key Note penis. It also neutralises traces of acidic urine in urethra.
Bulbourethral gland is also paired organ like seminal vesicles.
Vas deferens store and transport the sperms from the
epididymis towards the urethra. Semen
Semen = Sperms + Seminal fluid
Urethra
Urethra is a thin-walled muscular duct and it is a common Volume = 3 to 4 ml.
passage for both urine and semen in males hence, called pH = 7.2 – 7.7.
urinogenital duct. Normal sperm count = 20 – 120 million/ml.
The urethra originates from the urinary bladder and extends Semen is a greyish whitish fluid released during ejaculation
through the penis to its external opening called 10 .
which contains a mixture of spermatozoa (sperms) that are
Male External Genitalia produced in the testes and mixed with secretions from the
Penis male accessory sex glands (seminal fluid), including the
The penis is the male external genitalia. prostate gland, seminal vesicles, bulbourethral gland.
It is made up of special tissue that helps in erection of the 13 is found in seminal fluid, it acts as fuel to sperm.
penis to facilitate insemination. Fibrinogen, prostaglandin, citrate, inositol and several proteins
The enlarged end of penis called the glans penis is covered are also present in semen.
by a loose fold of skin called foreskin or prepuce. Ejaculation of semen is controlled by sympathetic nervous
EXTENDED LEARNING system.
P Wolffian duct: In males, wolffian duct or mesonephric
duct leads to the formation of epididymis, vas deferens and
seminal vesicle. Need to Know
P Erection of penis is regulated by parasympathetic nervous
system that causes vasodilation in smooth muscles of P Fluid secreted by the seminal vesicles normally constitutes
erectile tissue of penis by release of nitric oxide.
about 60% of the volume of semen.
Male Accessory Glands P Prostatic Fluid: Prostatic secretion forms about 30% of
1. Seminal Vesicles: Seminal vesicles are situated at the the volume of semen.
junction of vas deferens and prostate gland. They are narrow, It is slightly acidic, pH 6.5 due to the presence of
long pouches with muscular tissue on their wall. Seminal
citric acid.
vesicles are paired organs.
Secretion of seminal vesicle has an alkaline pH and is rich in
Prostatic secretion contains substances important for
fructose, ascorbic acid, prostaglandins and various enzymes. sperm mobility.
Cowper’s glands open into urethra before entering
Key Note into penis.
Cowper’s Fluid: Secretion of cowper’s gland is
The fructose, present in the seminal fluid, is the source of slightly alkaline and is produced during sexual
energy for the spermatozoa. stimulation.
P NEET (XII) Module-1 ZOOLOGY
4 W
