19.2.9 Testis — Easy NEET Notes
Location of Testis
- Testes are present in the scrotal sac.
- The scrotal sac lies outside the abdomen in males.
- Lower temperature in the scrotum helps in sperm formation.
Important Point
- Testis acts as:
- Primary sex organ → produces sperm
- Endocrine gland → secretes hormones
Structure of Testis
1. Seminiferous Tubules
- Coiled tube-like structures inside testis.
- Main site of spermatogenesis (formation of sperms).
2. Stromal / Interstitial Tissue
- Tissue present between seminiferous tubules.
- Contains Leydig cells.
Leydig Cells (Interstitial Cells)
- Found in intertubular spaces.
- Produce male sex hormones called androgens.
- Main androgen = Testosterone.
NEET Fact
- LH hormone from pituitary stimulates Leydig cells to produce testosterone.
Functions of Androgens (Testosterone)
1. Development of Male Reproductive Organs
Androgens help in growth and maturation of:
- Epididymis
- Vas deferens
- Seminal vesicles
- Prostate gland
- Urethra
2. Development of Secondary Sexual Characters
Testosterone causes:
- Growth of beard and moustache
- Axillary hair growth
- Muscular body
- Broad shoulders
- Deep/low-pitched voice
- Aggressive behaviour
Easy Memory Trick
“B-M-D-H”
- Beard
- Muscles
- Deep voice
- Hair growth
3. Role in Spermatogenesis
- Testosterone stimulates formation of sperms.
- Essential for normal sperm production.
4. Effect on Brain
- Influences male sexual behaviour.
- Responsible for libido (sexual desire).
5. Anabolic Effects
- Testosterone increases:
- Protein synthesis
- Muscle growth
- Carbohydrate metabolism
Word Meaning
- Anabolic = building up of body tissues.
NEET Quick Revision Points — Testis
| Topic | Important Point |
|---|---|
| Location | Scrotal sac |
| Functional unit | Seminiferous tubules |
| Hormone-producing cells | Leydig cells |
| Main hormone | Testosterone |
| Function | Spermatogenesis + male secondary sexual characters |
19.2.10 Ovary — Easy NEET Notes
Location of Ovary
- Females have a pair of ovaries.
- Located in the abdominal cavity.
Functions of Ovary
Ovary performs two major functions:
1. Production of Ovum
- One ovum is released during each menstrual cycle.
2. Hormone Secretion
Ovary secretes:
- Estrogen
- Progesterone
These are steroid hormones.
Structure of Ovary
1. Ovarian Follicles
- Contain developing ova.
- Growing follicles secrete estrogen.
2. Stromal Tissue
- Supporting connective tissue of ovary.
Corpus Luteum
- After ovulation, ruptured follicle changes into:
Corpus luteum
- Corpus luteum mainly secretes:
Progesterone
Important NEET Fact
- Corpus luteum is called the “temporary endocrine gland”.
Functions of Estrogen
1. Growth of Female Reproductive Organs
Stimulates growth and activity of:
- Uterus
- Fallopian tubes
- Vagina
2. Development of Female Secondary Sexual Characters
Estrogen causes:
- Breast development
- Broad pelvis
- Fat deposition
- Soft skin
3. Regulation of Menstrual Cycle
- Helps control menstrual cycle.
- Important for follicular growth.
Functions of Progesterone
1. Preparation of Uterus for Pregnancy
- Makes endometrium thick and vascular.
2. Maintenance of Pregnancy
- Prevents uterine contractions.
- Supports embryo implantation.
3. Mammary Gland Development
- Helps in preparation for lactation.
NEET Quick Revision Points — Ovary
| Topic | Important Point |
|---|---|
| Female gonad | Ovary |
| Female hormones | Estrogen & Progesterone |
| Estrogen source | Growing follicles |
| Progesterone source | Corpus luteum |
| Ovulation | Release of ovum |
Important Terms for NEET
| Term | Meaning |
|---|---|
| Androgens | Male sex hormones |
| Testosterone | Main male sex hormone |
| Spermatogenesis | Formation of sperms |
| Ovulation | Release of ovum |
| Corpus luteum | Yellow body formed after ovulation |
| Libido | Sexual desire |
Most Important NEET One-Liners
- Leydig cells produce testosterone.
- Seminiferous tubules are the site of sperm formation.
- Corpus luteum secretes progesterone.
- Estrogen is secreted by growing ovarian follicles.
- Testis acts both as reproductive organ and endocrine gland.
- Testosterone shows anabolic effects.
- Progesterone maintains pregnancy.
 |
| Structure and endocrine functions of Testis and Ovary for NEET and CBSE Class 11 Biology students. |
CBSE Class 11 Biology Questions
Chapter: Testis and Ovary (Endocrine Functions)
1. MCQs (Multiple Choice Questions)
1.
The hormone secreted by Leydig cells is:
- (a) Estrogen
- (b) Progesterone
- (c) Testosterone
- (d) Oxytocin
Answer:
(c) Testosterone
2.
The site of spermatogenesis is:
- (a) Leydig cells
- (b) Seminiferous tubules
- (c) Corpus luteum
- (d) Ovarian follicles
Answer:
(b) Seminiferous tubules
3.
The ruptured follicle after ovulation forms:
- (a) Graafian follicle
- (b) Corpus luteum
- (c) Endometrium
- (d) Placenta
Answer:
(b) Corpus luteum
4.
Progesterone is mainly secreted by:
- (a) Pituitary gland
- (b) Ovarian follicles
- (c) Corpus luteum
- (d) Thyroid gland
Answer:
(c) Corpus luteum
5.
The male sex hormones are collectively called:
- (a) Estrogens
- (b) Gonadotropins
- (c) Androgens
- (d) Prolactins
Answer:
(c) Androgens
6.
Which hormone is responsible for deepening of voice in males?
- (a) Estrogen
- (b) Progesterone
- (c) Testosterone
- (d) Insulin
Answer:
(c) Testosterone
7.
Estrogen is mainly secreted by:
- (a) Corpus luteum
- (b) Ovarian follicles
- (c) Leydig cells
- (d) Seminiferous tubules
Answer:
(b) Ovarian follicles
8.
The testes are located:
- (a) Inside abdomen
- (b) In thoracic cavity
- (c) In scrotal sac
- (d) In pelvic cavity
Answer:
(c) In scrotal sac
2. Very Short Answer Questions
1.
Name the cells that produce testosterone.
Answer:
Leydig cells
2.
What is spermatogenesis?
Answer:
Formation of sperms.
3.
Name the hormone secreted by corpus luteum.
Answer:
Progesterone
4.
Where are testes located?
Answer:
In the scrotal sac.
5.
Name two female sex hormones.
Answer:
Estrogen and Progesterone
3. Short Answer Questions
1.
Write two functions of testosterone.
Answer:
- Development of male secondary sexual characters.
- Stimulates spermatogenesis.
2.
What are seminiferous tubules?
Answer:
Seminiferous tubules are coiled structures present in testes where sperm formation occurs.
3.
What is corpus luteum? Mention its function.
Answer:
Corpus luteum is formed from ruptured ovarian follicle after ovulation.
It secretes progesterone.
4.
State the functions of estrogen.
Answer:
- Development of female secondary sexual characters.
- Growth of female reproductive organs.
- Regulation of menstrual cycle.
4. Long Answer Questions
1.
Explain the structure and functions of testis.
Answer:
Testes are present in the scrotal sac outside the abdomen. They act both as reproductive organs and endocrine glands.
Structure:
- Seminiferous tubules
- Interstitial tissue containing Leydig cells
Functions:
- Production of sperms
- Secretion of testosterone
Functions of Testosterone:
- Development of male reproductive organs
- Secondary sexual characters
- Spermatogenesis
- Muscle growth and protein synthesis
- Influences libido
2.
Describe the structure and functions of ovary.
Answer:
Ovaries are female gonads present in the abdominal cavity.
Structure:
- Ovarian follicles
- Stromal tissue
Hormones:
- Estrogen
- Progesterone
Functions:
Estrogen:
- Growth of female reproductive organs
- Secondary sexual characters
- Menstrual cycle regulation
Progesterone:
- Preparation of uterus for pregnancy
- Maintenance of pregnancy
5. Assertion and Reason Questions
1.
Assertion (A):
Leydig cells secrete testosterone.
Reason (R):
Leydig cells are present in interstitial spaces of testes.
- (a) Both A and R are true and R is the correct explanation.
- (b) Both A and R are true but R is not the correct explanation.
- (c) A is true but R is false.
- (d) A is false but R is true.
Answer:
(a) Both A and R are true and R is the correct explanation.
2.
Assertion (A):
Corpus luteum secretes progesterone.
Reason (R):
Corpus luteum is formed after ovulation.
Answer:
(a) Both A and R are true and R is the correct explanation.
6. Fill in the Blanks
- Testosterone is produced by ________ cells.
Answer:
Leydig
- Spermatogenesis occurs in ________ tubules.
Answer:
Seminiferous
- The female gonads are called ________.
Answer:
Ovaries
- Corpus luteum mainly secretes ________.
Answer:
Progesterone
- Estrogen is secreted by growing ovarian ________.
Answer:
Follicles
7. Match the Columns
| Column A | Column B |
|---|---|
| 1. Leydig cells | (a) Progesterone |
| 2. Corpus luteum | (b) Spermatogenesis |
| 3. Seminiferous tubules | (c) Testosterone |
| 4. Ovarian follicles | (d) Estrogen |
Answers:
1 → (c)
2 → (a)
3 → (b)
4 → (d)
8. Statement-Based Questions
1.
Statement I:
Testis acts as both reproductive and endocrine organ.
Statement II:
Testis produces testosterone hormone.
Answer:
Both statements are true.
2.
Statement I:
Estrogen develops female secondary sexual characters.
Statement II:
Progesterone is secreted by seminiferous tubules.
Answer:
Statement I is true, Statement II is false.
9. Case Study Questions
Case Study 1
A 16-year-old boy showed development of beard, muscular body, deep voice, and increased height during puberty.
Questions:
1.
Which hormone is responsible for these changes?
Answer:
Testosterone
2.
Name the cells producing this hormone.
Answer:
Leydig cells
3.
Which gland secretes this hormone?
Answer:
Testis
Case Study 2
After ovulation, the ruptured follicle in ovary transformed into a temporary structure that secretes a hormone necessary for pregnancy.
Questions:
1.
Name the structure formed after ovulation.
Answer:
Corpus luteum
2.
Which hormone is secreted by it?
Answer:
Progesterone
3.
Mention one function of this hormone.
Answer:
Maintenance of pregnancy.
Important CBSE & NEET One-Liners
- Leydig cells → Testosterone
- Seminiferous tubules → Spermatogenesis
- Corpus luteum → Progesterone
- Ovarian follicles → Estrogen
- Testis → Male gonad
- Ovary → Female gonad
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