CBSE Class 12 Biology Human Reproduction Notes

Download CBSE Class 12 Biology Human Reproduction Notes in PDF format. All Revision notes for Class 12 Biology have been designed as per the latest syllabus and updated chapters given in your textbook for Biology in Standard 12. Our teachers have designed these concept notes for the benefit of Grade 12 students. You should use these chapter wise notes for revision on daily basis. These study notes can also be used for learning each chapter and its important and difficult topics or revision just before your exams to help you get better scores in upcoming examinations, You can also use Printable notes for Class 12 Biology for faster revision of difficult topics and get higher rank. After reading these notes also refer to MCQ questions for Class 12 Biology given our website

Human Reproduction Class 12 Biology Revision Notes

Class 12 Biology students should refer to the following concepts and notes for Human Reproduction in standard 12. These exam notes for Grade 12 Biology will be very useful for upcoming class tests and examinations and help you to score good marks

Human Reproduction Notes Class 12 Biology

 

Chapter-3 HUMAN REPRODUCTION

The Male reproductive system

1. Penis

   a. Urination

   b. Sexual intercourse

      1. Corpus cavernosum- spongy tissue that fills with blood to make penis erect

      2. Glans- the head, end of penis

      3. Foreskin

         i. Covers glans,

         ii. May be removed surgically in an operation (circumcision)

2. Scrotum

a. Located behind penis

b. Contains two testes

c. Temperature sensitive (Sperm must be made in cooler conditions i.e, 2-3° C lower than body temperature)

3. Testes

a. Sperm is produced by the seminiferous tubules due to FSH

b. Testosterone is produced by Leydig cells due to LH

1. Causes the development of the male sex organs at ~8 weeks after conception.

2. Responsible for facial, armpit, and pubic hair, bone growth and muscular development.

c. Testes formed in the abdomen before birth. Descend through the "inguinal canal" during fetal or post-natal life. Sometimes it may take months/years to reach right place. Possible site for hernia.

4. Epididymis: Stores sperm until they have matured.

5. Vas deferens: Tube that leads from the epididymis to the urethra.Many sperm cells are stored here too.

6. Prostate gland: Provides an alkaline fluid that can protect sperm from harsh vaginal acids.

7. Seminal

Vesicles: Produce food for sperm. Food "Fructose"

8. Cowper's gland: Produces clear lubricating fluid

The Female Reproductive System

Ovary:

i) Each ovary contains immature ova (eggs) in follicles.

ii) Females born with lifetime supply of eggs(250,000-400,000 in each ovary)

iii) Ovaries release ovum -. Almost all ova degenerate between birth and puberty.

iv) Approx. 400 eggs will be ovulated over woman's life.

v) Egg is the largest human cell.

vi) Ovaries are located lower abdomen. 1 left and 1 on the right.

Fallopian tubes

i)Two thin tubes attached to the upper sides of uterus

ii) Tubes terminate near the ovaries but are not attached

iii)"Fimbriae" are finger-like structures on the end of each tube

iv)Tubes conduct egg to uterus by use of small hairs called "cilia"

v)Fertilization of ovum takes place in the ampullary-isthmic junction of the fallopian tubes. Egg viable for only 24-48 hours after ovulation.

Uterus:

i)Pear-shaped organ located in lower abdomen

ii)Muscles(myometrium) stretch to allow baby to develop. Oxytocin starts labor contractions.

iii)Lining of uterus (endometrium) thickens with blood-rich tissue due to progesterone

iv)Endometrium supports embryo/fetus during growth

v)Placenta It is the interface between baby and mother. If not pregnant, lining breaks down and is discharged from body through vagina. This is menstruation (period)

vi)Cervix connects uterus to vagina. Like a door that opens during ovulation. Cervical mucous closes the door at all other times.

Vagina:

Birth canal:

i)Menstrual blood leaves the body

ii) Organ of intercourse

iii) Muscular stretches to allow a baby to grow

iv)Vaginal opening partly remains closed by thin membrane of tissue called hymen. May be stretched or torn during any physical activity

Cervix:
i)Located at inner end of vagina
ii)Opening of uterus into vagina
iii) Mucous prevents bacteria and viruses from entering uterus
iv)Lets sperm into uterus after ovulation
v) Where baby also passes through during vaginal birth

Labia:
2 layers of skin, which fold over the opening to vagina and urethra
ii) Inner labia (labia minora)
iii)Outer labia (labia majora)
1.Two folds of skin, surround vaginal area
2. Pubic hair grows on outer labia

Clitoris:
i) Small organ, 5 to 10 millimeters long
ii) Located at junction of inner labia near front of body
iii) Contains erectile tissue& sexually sensitive
Mons pubis :Cushion like fatty tissue covered by skin and pubic hair
Gametogenesis & its hormonal regulation :
Ref: Concept Map Page C 3
Differentiate between: Spermatogenesis and Oogenesis :

CBSE Class 12 Biology - Human Reproduction_0

CBSE Class 12 Biology - Human Reproduction_0

CBSE Class 12 Biology - Human Reproduction_0


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