Stimulate the growth of ovarian follicle

Stimulate the appearance of secondary sex characters

Stimulate the growth of mammary gland

CHEMICAL COORDINATION AND INTEGRATION MCQs for NEET UG BIOLOGY — Easy

1 Easy

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Protein hormone bind to specific receptors that are located

View answer and explanation

Correct option: B

On the plasma membrane

Option B (On the plasma membrane) is correct because protein hormones are generally large and cannot cross the cell membrane, so they bind to receptors on the cell surface.

Solution approach

Correct Answer + Core Reason: On the plasma membrane. Protein hormones bind to cell surface receptors.

Step-by-Step Solution:

Step 1: Recall the mechanism of action of protein hormones.

Step 2: Understand that protein hormones are lipophobic and cannot cross the plasma membrane.

Step 3: Remember that protein hormones bind to receptors on the cell surface, initiating a signaling cascade.

Step 4: Conclude that protein hormone receptors are located on the plasma membrane.

Why other options are wrong:
- Option A: Free in cytoplasm is incorrect because protein hormone receptors are typically membrane-bound.
- Option C: Attached to DNA is incorrect because this is more typical of steroid hormone receptors.
- Option D: In the nucleus or cytoplasm is incorrect because protein hormones do not typically enter the cell.

Key Concepts:
- Protein hormones
- Hormone receptors
- Plasma membrane
- Signal transduction

Memory Aids:
- Protein hormones: Plasma membrane receptors
- Steroid hormones: Intracellular receptors

Quick Tips:
- Differentiate between the mechanisms of action of protein and steroid hormones.

2 Easy

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Identify the non antagonistic hormone among the following

View answer and explanation

Correct option: D

Adrenaline and Noradrenaline

Option D (Adrenaline and Noradrenaline) is correct because adrenaline and noradrenaline have similar effects and are not antagonistic.

Solution approach

Correct Answer + Core Reason: Adrenaline and Noradrenaline. These hormones have synergistic effects, not antagonistic ones.

Step-by-Step Solution:

Step 1: Define antagonistic hormones.

Step 2: Analyze the pairs of hormones and their effects.

Step 3: Adrenaline and noradrenaline have similar effects on the body.

Why other options are wrong:
- Option A: Somatocrinin stimulates growth hormone release, while somatostatin inhibits it (antagonistic).
- Option B: Insulin lowers blood glucose, while glucagon raises it (antagonistic).
- Option C: Calcitonin lowers blood calcium, while parathormone raises it (antagonistic).

Key Concepts:
- Antagonistic hormones
- Insulin and glucagon
- Calcitonin and parathormone
- Adrenaline and noradrenaline

Memory Aids:
- Antagonistic = opposite effects

Quick Tips:
- Understand the effects of each hormone pair on the body.

3 Easy

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Which one of the following statement is correct?

View answer and explanation

Correct option: A

Endrocrine glands regulate neural activity, and nervous
system regulates endocrine glands

Option A (Endocrine glands regulate neural activity, and nervous system regulates endocrine glands) is correct because there is a bidirectional relationship between the endocrine and nervous systems, where each influences the other's activity.

Solution approach

Correct Answer + Core Reason: Endrocrine glands regulate neural activity, and nervous\nsystem regulates endocrine glands. Both systems influence each other.

Step-by-Step Solution:

Step 1: Recall the interaction between the endocrine and nervous systems.

Step 2: Consider the relationship:\nA. Endocrine glands regulate neural activity, and nervous system regulates endocrine glands: This is a correct bidirectional relationship.\nB. Neither hormones control neural activity nor the neurons control endocrine activity: This is incorrect as both systems interact.\nC. Endocrine glands regulate neural activity, but not vice- versa: This is incorrect as the nervous system also regulates endocrine activity.\nD. Neurons regulate endocrine activity, but not vice versa: This is incorrect as endocrine glands also regulate neural activity.

Step 3: Identify the correct statement.

Why other options are wrong:
- Option B: Both systems interact and regulate each other.
- Option C: The nervous system also regulates endocrine activity.
- Option D: Endocrine glands also regulate neural activity.

Key Concepts:\nEndocrine system, nervous system, regulation, interaction

Memory Aids:\nRemember that the endocrine and nervous systems work together to maintain homeostasis.

Quick Tips:\nUnderstand the bidirectional communication between the endocrine and nervous systems.

4 Easy

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Identify from the following, a hormone produced by the pituitary gland in both males and females but functional only in females.

View answer and explanation

Correct option: C

Prolactin

Option C (Prolactin) is correct because prolactin is produced by the pituitary gland in both males and females, but its primary function is to stimulate milk production in females after childbirth.

Solution approach

Correct Answer + Core Reason: Prolactin. Prolactin is produced in both sexes but is primarily functional in females for milk production.

Step-by-Step Solution:

Step 1: Consider the hormones produced by the pituitary gland.

Step 2: Evaluate the function of each hormone in males and females.

Step 3: Prolactin is involved in milk production (lactation) in females after childbirth. While present in males, its function is not as well-defined.

Step 4: Vasopressin and Somatotrophic hormone (Growth hormone) have similar functions in both males and females. Relaxin is primarily produced by the ovaries and placenta in females.

Why other options are wrong:
- Option A: Vasopressin functions similarly in both males and females (water reabsorption in the kidneys).
- Option B: Relaxin is primarily produced by the ovaries and placenta in females, not the pituitary gland.
- Option D: Somatotrophic hormone (Growth hormone) functions similarly in both males and females (growth and metabolism).

Key Concepts:
- Pituitary hormones
- Prolactin function
- Sexual dimorphism in hormone function

Memory Aids:
- Prolactin: Pro-lactation (promotes milk production)

Quick Tips:
- Remember the specific functions of each pituitary hormone in both sexes.

5 Easy

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Diabetes mellitus takes place only when

View answer and explanation

Correct option: D

β- cells of pancreas are in hypo

Option D (β- cells of pancreas are in hypo) is correct because Diabetes mellitus occurs when there is insufficient insulin production due to hypoactivity of beta cells.

Solution approach

Correct Answer + Core Reason: β- cells of pancreas are in hypo. Diabetes mellitus is primarily caused by a deficiency in insulin production or action.

Step-by-Step Solution:

Step 1: Understand the role of insulin in glucose regulation.

Step 2: Insulin, produced by the beta cells of the pancreas, is responsible for lowering blood glucose levels by facilitating glucose uptake into cells.

Step 3: When beta cells are hypoactive, they produce insufficient insulin, leading to elevated blood glucose levels and diabetes mellitus.

Why other options are wrong:
- Option A: Excess alpha cells would lead to excess glucagon, increasing blood sugar, but not directly causing diabetes mellitus.
- Option B: Excess beta cells would lead to excess insulin, causing hypoglycemia, not diabetes mellitus.
- Option C: Hypoactivity of alpha cells would lead to decreased glucagon, potentially lowering blood sugar, not causing diabetes mellitus.

Key Concepts:
- Insulin function
- Beta cells of the pancreas
- Diabetes mellitus

Memory Aids:
- Beta cells make insulin, and insulin lowers blood sugar.

Quick Tips:
- Remember the relationship between insulin, beta cells, and blood glucose levels.

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A child with a weak immune system. Which of the following gland could be the cause of the problem?

View answer and explanation

Correct option: C

Thymus

The correct answer is C (Thymus) because the thymus gland is crucial for the development of the immune system, particularly T-lymphocytes, and its dysfunction can lead to a weak immune system in children.

Solution approach

Correct Answer + Core Reason: Thymus. The thymus gland is crucial for the development of the immune system.

Step-by-Step Solution:

Step 1: Recall the function of the thymus gland: The thymus gland is responsible for the maturation and differentiation of T-lymphocytes, which are essential for cell-mediated immunity.

Step 2: Understand the importance of T-lymphocytes in the immune system: T-lymphocytes play a critical role in recognizing and destroying infected cells, regulating immune responses, and coordinating other immune cells.

Step 3: Relate thymus dysfunction to a weak immune system: If the thymus gland is not functioning properly, it can lead to a deficiency in T-lymphocytes, resulting in a weakened immune system and increased susceptibility to infections.

Why other options are wrong:
- Option A: Thyroid gland is involved in metabolism and growth, not directly related to the development of the immune system.
- Option B: Parathyroid gland is involved in regulating calcium levels in the blood, not directly related to the development of the immune system.
- Option D: Pituitary gland is involved in regulating various hormonal functions, but not directly related to the development of the immune system in the same way as the thymus.

Key Concepts:
- Thymus gland
- T-lymphocytes
- Immune system
- Cell-mediated immunity

Memory Aids:
- Think of "Thymus" and "T-cells" being essential for a strong immune system in children.

Quick Tips:
- Remember that the thymus gland is crucial for the development of the immune system, especially in early life, and its dysfunction can lead to a weak immune system.

7 Easy

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A: Immune response of old person becomes weak
R: Thymus is degenerated in old individual

View answer and explanation

Correct option: A

A and R are correct R is correct explanation for A

The correct answer is A (A and R are correct R is correct explanation for A) because the thymus gland degenerates in old age, which weakens the immune response.

Solution approach

Correct Answer + Core Reason: A and R are correct R is correct explanation for A. The thymus gland's degeneration directly causes a weaker immune response in older individuals.

Step-by-Step Solution:

Step 1: Analyze the assertion: The immune response of an old person becomes weak. This is generally true due to immunosenescence.

Step 2: Analyze the reason: The thymus is degenerated in old individuals. This is also true; the thymus undergoes involution with age.

Step 3: Determine the relationship: The degeneration of the thymus gland directly contributes to the weakening of the immune response in old age because the thymus is responsible for T-lymphocyte maturation.

Why other options are wrong:
- Option B: While both statements are correct, the reason *is* the correct explanation for the assertion.
- Option C: The reason is not incorrect; it's a valid explanation.
- Option D: Both the assertion and the reason are correct.

Key Concepts:
- Thymus gland
- Immune system
- Aging
- Immunosenescence
- T-lymphocytes

Memory Aids:
- Remember that the thymus is vital for T-cell development, and its decline impacts immunity.

Quick Tips:
- Always consider the direct link between the gland's function and the observed effect.

8 Easy

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How many Islets of Langerhans are present in normal human pancreas?

View answer and explanation

Correct option: A

1 to 2 million

Option A (1 to 2 million) is correct because a normal human pancreas contains approximately 1 to 2 million Islets of Langerhans.

Solution approach

Correct Answer + Core Reason: 1 to 2 million. This is the approximate number of Islets in a human pancreas.

Step-by-Step Solution:

Step 1: Recall the number of Islets: The Islets of Langerhans are numerous but small clusters of cells within the pancreas.

Step 2: Identify the correct range: A normal human pancreas contains approximately 1 to 2 million Islets of Langerhans.

Why other options are wrong:
- Option B: 2 to 3 million is higher than the actual number.
- Option C: 3 to 4 million is significantly higher than the actual number.
- Option D: 4 to 5 million is much higher than the actual number.

Key Concepts:
- Islets of Langerhans
- Pancreas structure

Memory Aids:
- Think of "millions" of tiny islets.

Quick Tips:
- Remember the approximate number of Islets in a normal pancreas.

9 Easy

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Ovary produces

View answer and explanation

Correct option: D

All of these

Option D (All of these) is correct because the ovary produces one ovum each month, as well as the hormones progesterone and estrogen.

Solution approach

Correct Answer + Core Reason: All of these. The ovary produces all the listed items.

Step-by-Step Solution:

Step 1: Recall the functions of the ovary.

Step 2: Remember that the ovary produces ova (eggs) during the menstrual cycle.

Step 3: Understand that the ovary also produces the hormones estrogen and progesterone.

Step 4: Conclude that all the options are correct.

Why other options are wrong:
- Option A: One ovum at each month is correct, but not the complete answer.
- Option B: Progesterone is correct, but not the complete answer.
- Option C: Estrogen is correct, but not the complete answer.

Key Concepts:
- Ovary
- Ovum
- Estrogen
- Progesterone
- Female reproductive system

Memory Aids:
- Ovary: Ova, Estrogen, Progesterone

Quick Tips:
- Remember the key hormones produced by the ovaries and their functions.

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Progesterone is secreted by

View answer and explanation

Correct option: A

Corpus luteum

Option A (Corpus luteum) is correct because the corpus luteum, formed after ovulation, is the primary source of progesterone secretion.

Solution approach

Correct Answer + Core Reason: Corpus luteum. The corpus luteum is the primary source of progesterone secretion.

Step-by-Step Solution:

Step 1: Identify the source of progesterone.

Step 2: Progesterone is a steroid hormone that plays a key role in the menstrual cycle and pregnancy.

Step 3: After ovulation, the ruptured follicle transforms into the corpus luteum.

Step 4: The corpus luteum secretes large amounts of progesterone, which prepares the uterine lining for implantation and maintains pregnancy.

Why other options are wrong:
- Option B: The uterus is the target organ for progesterone, but it does not secrete it.
- Option C: The placenta secretes progesterone during pregnancy, but it is not the primary source early in the cycle.
- Option D: The Graafian follicle produces estrogen before ovulation, not progesterone.

Key Concepts:
- Progesterone function
- Corpus luteum
- Menstrual cycle
- Pregnancy

Memory Aids:
- "Corpus Luteum" sounds like "Corpus Loot-e-um", think of it as looting the follicle after ovulation to produce progesterone.

Quick Tips:
- Remember that the corpus luteum is formed after ovulation and secretes progesterone.

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Pituitary gland is derived from

View answer and explanation

Correct option: A

Ectoderm

Option A (Ectoderm) is correct because the pituitary gland is embryologically derived from the ectoderm.

Solution approach

Correct Answer + Core Reason: Ectoderm. The pituitary gland originates from the ectodermal tissue during embryonic development.

Step-by-Step Solution:

Step 1: Recall the embryonic origins of different tissues and organs.

Step 2: The pituitary gland has a dual origin: the adenohypophysis (anterior pituitary) arises from Rathke's pouch, an ectodermal invagination of the oral cavity, and the neurohypophysis (posterior pituitary) arises from a downgrowth of the diencephalon, which is also ectodermal in origin.

Step 3: Therefore, the entire pituitary gland is derived from ectoderm.

Why other options are wrong:
- Option B: Endoderm gives rise to the lining of the digestive tract and associated organs, not the pituitary gland.
- Option C: Mesoderm gives rise to muscle, bone, blood vessels, and connective tissues, not the pituitary gland.
- Option D: This option is incorrect because the pituitary gland is indeed derived from the ectoderm.

Key Concepts:
- Embryonic development
- Germ layers (ectoderm, mesoderm, endoderm)
- Origin of pituitary gland

Memory Aids:
- Ectoderm: \"Outer\" - Think of the outer layers of the body and nervous system, including the pituitary gland.

Quick Tips:
- Remember the general derivatives of each germ layer: ectoderm (skin, nervous system), mesoderm (muscle, bone, blood), and endoderm (digestive lining).

12 Easy

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Which hormone /gland acts as biological clocks?

View answer and explanation

Correct option: D

Pineal

Option D (Pineal) is correct because the pineal gland secretes melatonin, which regulates sleep-wake cycles and acts as a biological clock.

Solution approach

Correct Answer + Core Reason: Pineal. The pineal gland secretes melatonin, which regulates circadian rhythms.

Step-by-Step Solution:

Step 1: Recall the function of the pineal gland.

Step 2: The pineal gland secretes melatonin.

Step 3: Melatonin regulates sleep-wake cycles (circadian rhythms).

Step 4: Therefore, the pineal gland acts as a biological clock.

Why other options are wrong:
- Option A: The thyroid gland regulates metabolism, not circadian rhythms.
- Option B: The thymus gland is involved in immune function, not circadian rhythms.
- Option C: The adrenal glands produce hormones involved in stress response and electrolyte balance, not primarily circadian rhythms.
- Option D: The pineal gland secretes melatonin, which regulates sleep-wake cycles.

Key Concepts:
- Endocrine System
- Pineal Gland
- Melatonin
- Circadian Rhythms

Memory Aids:
- Pineal = Pillow (relates to sleep).

Quick Tips:
- Know the primary hormones and functions of each endocrine gland.

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Which one of the following pair correctly matches a hormone with a disease resulting from its deficiency?

View answer and explanation

Correct option: A

Parathyroid hormone— Tetany

Option A (Parathyroid hormone— Tetany) is correct because a deficiency in parathyroid hormone leads to hypocalcemia, which can cause tetany (muscle spasms).

Solution approach

Correct Answer + Core Reason: Parathyroid hormone deficiency leads to Tetany.

Step-by-Step Solution:

Step 1: Parathyroid hormone (PTH) regulates calcium levels in the blood.

Step 2: PTH deficiency (hypoparathyroidism) leads to decreased blood calcium levels (hypocalcemia).

Step 3: Hypocalcemia increases neuronal excitability, leading to muscle spasms and tetany.

Why other options are wrong:
- Option B: Insulin deficiency leads to Diabetes mellitus, not Diabetes insipidus. Diabetes insipidus is due to ADH deficiency.
- Option C: Relaxin is involved in pregnancy and labor; its deficiency does not cause Gigantism. Gigantism is caused by excess growth hormone.
- Option D: Prolactin is involved in milk production; its deficiency does not cause Cretinism. Cretinism is caused by thyroid hormone deficiency.

Key Concepts:
- Parathyroid hormone (PTH)
- Calcium regulation
- Tetany

Memory Aids:
- PTH raises calcium levels; deficiency leads to muscle spasms.

Quick Tips:
- Associate PTH with calcium regulation and tetany with hypocalcemia.

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Name the hormone that stimulates the secretion of gastric juice.

View answer and explanation

Correct option: D

Gastrin

Option D (Gastrin) is correct because gastrin is a hormone secreted by the stomach that stimulates the secretion of gastric juice (hydrochloric acid and pepsinogen).

Solution approach

Correct Answer + Core Reason: Gastrin. Gastrin stimulates the secretion of gastric juice in the stomach.

Step-by-Step Solution:

Step 1: Gastrin is a peptide hormone secreted by G cells in the stomach in response to stimuli such as the presence of food, especially proteins, in the stomach.

Step 2: Gastrin stimulates the parietal cells in the stomach to secrete hydrochloric acid (HCl) and the chief cells to secrete pepsinogen, the precursor to pepsin.

Step 3: These secretions contribute to the formation of gastric juice, which is essential for the digestion of proteins in the stomach.

Why other options are wrong:
- Option A: Rennin is an enzyme that helps in the coagulation of milk protein, primarily found in infants. It is not the primary hormone stimulating gastric juice secretion.
- Option B: Enterokinase is an enzyme secreted by the duodenum that activates trypsinogen to trypsin, playing a role in protein digestion in the small intestine.
- Option C: Enterogastrone is a hormone secreted by the duodenum that inhibits gastric secretion and motility.

Key Concepts:
- Gastrin
- Gastric juice
- Hydrochloric acid (HCl)
- Pepsinogen
- Stomach

Memory Aids:
- Gastrin \"gasses\" up the stomach with gastric juice.

Quick Tips:
- Know the hormones and enzymes involved in digestion and their functions.

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MSH is produced by

View answer and explanation

Correct option: D

Pars intermedia

Option D (Pars intermedia) is correct because MSH (Melanocyte-Stimulating Hormone) is produced by the pars intermedia of the pituitary gland.

Solution approach

Correct Answer + Core Reason: Pars intermedia. MSH is produced by the pars intermedia of the pituitary gland.

Step-by-Step Solution:

Step 1: Recall the different parts of the pituitary gland.

Step 2: The pituitary gland has two main parts: the anterior pituitary (adenohypophysis) and the posterior pituitary (neurohypophysis). In some animals, there is also a pars intermedia.

Step 3: MSH is produced by the pars intermedia, which is located between the anterior and posterior pituitary.

Why other options are wrong:
- Option A: Thyroid: The thyroid gland produces thyroid hormones (T3 and T4) and calcitonin.
- Option B: Anterior pituitary: The anterior pituitary produces hormones like GH, PRL, ACTH, TSH, FSH, and LH.
- Option C: Posterior pituitary: The posterior pituitary stores and releases hormones produced by the hypothalamus (ADH and oxytocin).

Key Concepts:
- Pituitary gland structure and function
- MSH

Memory Aids:
- Pars intermedia = \"middle part\" of the pituitary.

Quick Tips:
- Know the hormones produced by each part of the pituitary gland.

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To yield more milk, cow is injected with

View answer and explanation

Correct option: B

Prolactin

Option B (Prolactin) is correct because prolactin is the hormone responsible for milk production in mammals.

Solution approach

Correct Answer + Core Reason: Prolactin. Prolactin is the hormone responsible for milk production (lactation).

Step-by-Step Solution:

Step 1: Recall the hormones involved in milk production.

Step 2: Prolactin is the primary hormone responsible for stimulating milk production in the mammary glands.

Step 3: Other hormones like oxytocin are involved in milk ejection, but prolactin is key for milk synthesis.

Why other options are wrong:
- Option A: Sorbitol - Sorbitol is a sugar alcohol and is not involved in milk production.
- Option C: Gonadotrophs - Gonadotrophs are hormones that stimulate the gonads (ovaries and testes) and are not directly involved in milk production.
- Option D: Sterol - Sterols are a type of lipid and are not directly involved in stimulating milk production, although they are components of milk.

Key Concepts:
- Hormones
- Lactation
- Prolactin

Memory Aids:
- Prolactin = Pro-lactation

Quick Tips:
- Remember the primary function of prolactin.

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In situation of fear, in blood there is increase of

View answer and explanation

Correct option: C

Adrenaline

Option C is correct because adrenaline is released in response to fear, preparing the body for "fight or flight".

Solution approach

Correct Answer + Core Reason: C. Adrenaline. Adrenaline is released during stressful situations like fear.

Step-by-Step Solution:

Step 1: Recall the hormones released during stress.

Step 2: Adrenaline (epinephrine) is released by the adrenal medulla in response to stress, fear, or excitement.

Step 3: This hormone prepares the body for "fight or flight" by increasing heart rate, blood pressure, and energy availability.

Why other options are wrong:
- Option A: Insulin decreases blood glucose levels and is not typically associated with fear.
- Option B: Androgens are sex hormones and are not directly related to acute fear responses.
- Option D: Oestrogen is a female sex hormone and is not directly related to acute fear responses.

Key Concepts:
- Adrenaline (epinephrine) release
- Stress response
- "Fight or flight" response

Memory Aids:
- Adrenaline: Released during stress and emergencies.

Quick Tips:
- Remember the role of adrenaline in the stress response.

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Hypothyroidism causes

View answer and explanation

Correct option: C

Both (a) and (b)

Option C (Both (a) and (b)) is correct because hypothyroidism in children causes cretinism, characterized by stunted growth and mental retardation, while hypothyroidism in adults causes myxoedema, characterized by swelling of the skin and tissues.

Solution approach

Correct Answer + Core Reason: Both (a) and (b). Hypothyroidism causes both myxoedema and cretinism.

Step-by-Step Solution:

Step 1: Define hypothyroidism.

Step 2: Hypothyroidism is a condition characterized by insufficient production of thyroid hormones (thyroxine and triiodothyronine).

Step 3: Hypothyroidism in children leads to cretinism, which includes stunted growth, mental retardation, and abnormal skin.

Step 4: Hypothyroidism in adults leads to myxoedema, which includes swelling of the skin and tissues, fatigue, and weight gain.

Step 5: Exophthalmic goitre is associated with hyperthyroidism, not hypothyroidism.

Why other options are wrong:
- Option A: Myxoedema is a symptom of hypothyroidism, but it's not the only one.
- Option B: Cretinism is a symptom of hypothyroidism, but it's not the only one.
- Option D: Exophthalmic goitre is a symptom of hyperthyroidism.

Key Concepts:
- Hypothyroidism and its effects
- Cretinism vs. myxoedema

Memory Aids:
- Hypo = Low thyroid

Quick Tips:
- Differentiate between the effects of hypothyroidism in children and adults.

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Progesterone pill helps in preventing pregnancy by not allowing

View answer and explanation

Correct option: A

Ova formation

Option A (Ova formation) is correct because progesterone pills primarily prevent pregnancy by inhibiting ovulation, which is the process of ova formation.

Solution approach

Correct Answer + Core Reason: Ova formation. Progesterone pills prevent pregnancy by inhibiting ovulation.

Step-by-Step Solution:

Step 1: Progesterone pills work by mimicking the effects of progesterone, a hormone naturally produced in the body.

Step 2: The primary mechanism of action is to suppress the release of Gonadotropin-Releasing Hormone (GnRH), which in turn reduces the secretion of Luteinizing Hormone (LH) and Follicle-Stimulating Hormone (FSH).

Step 3: Reduced LH and FSH levels prevent the development of ovarian follicles and inhibit ovulation (ova formation).

Step 4: Without ovulation, there is no egg available to be fertilized, thus preventing pregnancy.

Why other options are wrong:
- Option B: Fertilization can be prevented by other methods, but progesterone pills primarily target ovulation, not fertilization directly. While they can affect cervical mucus making it harder for sperm to travel, this is a secondary effect.
- Option C: Implantation is prevented by other types of contraception, such as IUDs or emergency contraception pills, but not primarily by progesterone-only pills. Progesterone pills mainly work before fertilization occurs.
- Option D: This is incorrect because progesterone pills do have a specific mechanism of action.

Key Concepts:
- Hormonal contraception
- Ovulation
- Progesterone
- LH and FSH

Memory Aids:
- Progesterone \"pro-gestation\" helps prevent pregnancy by stopping the egg from forming (ova formation).

Quick Tips:
- Understand the different mechanisms of action for various contraceptive methods.

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Estrogen

View answer and explanation

Correct option: D

All of the above

Option D (All of the above) is correct because estrogen stimulates the growth of ovarian follicles, the appearance of secondary sex characters, and the growth of mammary glands.

Solution approach

Correct Answer + Core Reason: All of the above. Estrogen stimulates the growth of ovarian follicle, the appearance of secondary sex characters and the growth of mammary gland.

Step-by-Step Solution:

Step 1: Identify the functions of estrogen.

Step 2: Estrogen is a group of steroid hormones primarily produced by the ovaries.

Step 3: Estrogen stimulates the growth and development of ovarian follicles, promotes the appearance of secondary sexual characteristics in females, and stimulates the growth of mammary glands.

Why other options are wrong:
- Option A: Estrogen does stimulate the growth of ovarian follicles, but it also has other functions.
- Option B: Estrogen does stimulate the appearance of secondary sex characters, but it also has other functions.
- Option C: Estrogen does stimulate the growth of mammary gland, but it also has other functions.

Key Concepts:
- Estrogen function
- Ovarian follicles
- Secondary sexual characteristics
- Mammary glands

Memory Aids:
- Remember that estrogen has multiple roles in female reproductive development and function.

Quick Tips:
- Know the various functions of estrogen in the female body.

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The Leydig cells or …A… cells which are present in …B… . Spaces produce a group of hormone called androgens mainly …C…
Choose the correct option for A, B and C

View answer and explanation

Correct option: D

A-interstitial cells, B-intertubular spaces, C-testosterone

Option D (A-interstitial cells, B-intertubular spaces, C-testosterone) is correct because Leydig cells (also known as interstitial cells) are found in the intertubular spaces and produce testosterone.

Solution approach

Correct Answer + Core Reason: A-interstitial cells, B-intertubular spaces, C-testosterone. Leydig cells (interstitial cells) are in the intertubular spaces and produce testosterone.

Step-by-Step Solution:
Step 1: Recall the location and function of Leydig cells.
Step 2: Leydig cells, also known as interstitial cells, are located in the intertubular spaces of the testes.
Step 3: These cells produce androgens, mainly testosterone.
Step 4: Therefore, A is interstitial cells, B is intertubular spaces, and C is testosterone.

Why other options are wrong:
- Option A: A-interstitial cells, B-intratubular spaces, C-testosterone is incorrect because Leydig cells are located in the intertubular spaces, not the intratubular spaces.
- Option B: A-intrastitial cells, B-intertubular spaces, C-testosterone is incorrect because the correct spelling is interstitial cells.
- Option C: A-intrastitial cells, B-intratubular spaces, C-testosterone is incorrect because the correct spelling is interstitial cells and Leydig cells are located in the intertubular spaces, not the intratubular spaces.

Key Concepts:
- Leydig cells (interstitial cells)
- Location of Leydig cells in the testes
- Function of Leydig cells (testosterone production)

Memory Aids:
- Leydig = Testosterone

Quick Tips:
- Remember that Leydig cells produce testosterone.

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Identify which of the following are endocrine glands? I. Liver, II. Gastric gland,  III. Pituitary gland, IV. Thyroid.   Choose the correct option

View answer and explanation

Correct option: B

III and IV

Option B (III and IV) is correct because the pituitary gland and thyroid are endocrine glands, while the liver and gastric gland have other primary functions besides hormone secretion.

Solution approach

Correct Answer + Core Reason: III and IV. Pituitary gland and thyroid are endocrine glands.

Step-by-Step Solution:

Step 1: Define endocrine glands. Endocrine glands secrete hormones directly into the bloodstream.

Step 2: Consider each option:
- I. Liver: The liver has many functions, but it is primarily an exocrine gland and not solely an endocrine gland.
- II. Gastric gland: The gastric gland secretes digestive enzymes and hydrochloric acid, primarily an exocrine function, although some cells produce hormones.
- III. Pituitary gland: The pituitary gland is a major endocrine gland that secretes many hormones.
- IV. Thyroid: The thyroid gland is an endocrine gland that secretes thyroid hormones.

Step 3: Identify the endocrine glands: Pituitary and thyroid.

Why other options are wrong:
- Option A: I and II: Liver and gastric gland are primarily exocrine.
- Option C: I and IV: Liver is primarily exocrine.
- Option D: II and IV: Gastric gland is primarily exocrine.

Key Concepts:
- Endocrine vs. exocrine glands

Memory Aids:
- Endocrine = \"into\" the blood.

Quick Tips:
- Know the primary functions of different organs.

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GnRh (Gonadotropin Releasing Hormone) stimulates the

View answer and explanation

Correct option: B

Pituitary for synthesis and release of gonadotropin

Option B (Pituitary for synthesis and release of gonadotropin) is correct because GnRH stimulates the anterior pituitary gland to synthesize and release gonadotropins (LH and FSH).

Solution approach

Correct Answer + Core Reason: Pituitary for synthesis and release of gonadotropin. GnRH stimulates both the synthesis and release of gonadotropins (LH and FSH) from the anterior pituitary.

Step-by-Step Solution:

Step 1: Recall the function of GnRH (Gonadotropin-Releasing Hormone).

Step 2: GnRH is secreted by the hypothalamus and acts on the anterior pituitary gland.

Step 3: GnRH stimulates the anterior pituitary to synthesize and release two gonadotropins: Luteinizing Hormone (LH) and Follicle-Stimulating Hormone (FSH).

Step 4: LH and FSH then act on the gonads (testes in males and ovaries in females) to regulate reproductive functions.

Why other options are wrong:
- Option A: GnRH stimulates the pituitary for both synthesis and release, not just release.
- Option C: GnRH acts on the pituitary, not directly on the testes.
- Option D: GnRH is released by the hypothalamus, but it doesn't stimulate the hypothalamus itself.

Key Concepts:
- GnRH function
- Hypothalamic-pituitary-gonadal axis
- Gonadotropins (LH and FSH)

Memory Aids:
- GnRH: Gonadotropin-Releasing Hormone (Releases gonadotropins from the pituitary)
- LH: Luteinizing Hormone
- FSH: Follicle-Stimulating Hormone

Quick Tips:
- Understand the hierarchical control of hormone secretion (hypothalamus -> pituitary -> target gland).

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Hormone is a/an

View answer and explanation

Correct option: B

Chemical messenger

Option B (Chemical messenger) is correct because hormones are signaling molecules transported via the circulatory system to regulate physiology and behavior.

Solution approach

Correct Answer + Core Reason: Chemical messenger. Hormones transmit signals between cells.

Step-by-Step Solution:

Step 1: Define hormone. A hormone is a regulatory substance produced in an organism and transported in tissue fluids such as blood or sap to stimulate specific cells or tissues into action.

Step 2: Consider the options.

Step 3: Evaluate each option:
- Enzyme: Enzymes are biological catalysts.
- Chemical messenger: Hormones are chemical messengers.
- Excretory product: Excretory products are waste materials.
- Glandular secretion: Hormones are a type of glandular secretion, but \"chemical messenger\" is a more precise and encompassing definition.

Step 4: Conclusion: Hormones function as chemical messengers.

Why other options are wrong:
- Option A: Enzymes are biological catalysts, not messengers.
- Option C: Excretory products are waste materials, not signaling molecules.
- Option D: While hormones are secreted by glands, the primary function is to act as a chemical messenger.

Key Concepts:
- Hormones as signaling molecules
- Endocrine system

Memory Aids:
- Think of hormones as \"mailmen\" delivering messages.

Quick Tips:
- Remember the role of hormones in cell communication.

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Which one of the following is the hormone of adrenal medulla?

View answer and explanation

Correct option: D

Epinephrine

Option D (Epinephrine) is correct because epinephrine (adrenaline) is a hormone secreted by the adrenal medulla.

Solution approach

Correct Answer + Core Reason: Epinephrine. Epinephrine (adrenaline) is secreted by the adrenal medulla.

Step-by-Step Solution:
Step 1: Recall the hormones secreted by the adrenal medulla.
Step 2: The adrenal medulla secretes epinephrine (adrenaline) and norepinephrine (noradrenaline).
Step 3: Therefore, epinephrine is the hormone of the adrenal medulla.

Why other options are wrong:
- Option A: Prolactin is incorrect because prolactin is secreted by the anterior pituitary gland.
- Option B: ACTH is incorrect because ACTH is secreted by the anterior pituitary gland and stimulates the adrenal cortex.
- Option C: Corticosterone is incorrect because corticosterone is secreted by the adrenal cortex.

Key Concepts:
- Adrenal medulla hormones
- Epinephrine (adrenaline)
- Norepinephrine (noradrenaline)

Memory Aids:
- Adrenal medulla = Epinephrine and Norepinephrine

Quick Tips:
- Remember that the adrenal medulla secretes epinephrine and norepinephrine.

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Presence of which of the following conditions in urine is indicative of Diabetes mellitus.

View answer and explanation

Correct option: B

Ketonuria and Glycosuria

Option B (Ketonuria and Glycosuria) is correct because the presence of ketones and glucose in the urine are indicative of Diabetes mellitus.

Solution approach

Correct Answer + Core Reason: Ketonuria and Glycosuria. These are the key indicators of Diabetes mellitus in urine.

Step-by-Step Solution:

Step 1: Define Diabetes Mellitus: Diabetes mellitus is a metabolic disorder characterized by hyperglycemia (high blood sugar).

Step 2: Glycosuria: Glycosuria is the presence of glucose in the urine, which occurs when blood glucose levels are too high for the kidneys to reabsorb it all.

Step 3: Ketonuria: Ketonuria is the presence of ketone bodies in the urine, which occurs when the body breaks down fat for energy due to insufficient insulin or glucose utilization.

Step 4: Conclusion: The presence of both glucose and ketone bodies in the urine strongly suggests Diabetes mellitus.

Why other options are wrong:
- Option A: Uremia and Renal calculi: Uremia indicates kidney failure, and renal calculi are kidney stones. While diabetes can lead to kidney problems, these are not the primary indicators in urine.
- Option C: Renal calculi and Hyperglycaemia: Hyperglycemia is in the blood, not urine. Renal calculi are kidney stones, not primary indicators in urine.
- Option D: Uremia and Ketonuria: Uremia indicates kidney failure. While ketonuria is related to diabetes, uremia is not a direct indicator of diabetes in urine.

Key Concepts:
- Diabetes mellitus
- Glycosuria
- Ketonuria
- Kidney function

Memory Aids:
- Glycosuria: Glucose in urine
- Ketonuria: Ketones in urine

Quick Tips:
- Remember the key indicators of diabetes mellitus are related to glucose and ketone metabolism.

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Reabsorption of water in DCT and CT part of nephron is function of

View answer and explanation

Correct option: C

Vasopressin

Option C (Vasopressin) is correct because vasopressin (ADH) regulates water reabsorption in the DCT and collecting tubules of the nephron.

Solution approach

Correct Answer + Core Reason: Vasopressin. Vasopressin (ADH) regulates water reabsorption in the DCT and CT.

Step-by-Step Solution:

Step 1: Recall the function of the distal convoluted tubule (DCT) and collecting tubule (CT) in the nephron. These parts of the nephron are responsible for regulating water reabsorption based on the body's needs.

Step 2: Identify the hormone responsible for water reabsorption in the DCT and CT. Vasopressin, also known as antidiuretic hormone (ADH), increases the permeability of the DCT and CT to water, allowing more water to be reabsorbed into the bloodstream.

Step 3: Consider the other options. Prolactin is involved in milk production, oxytocin is involved in uterine contractions and milk ejection, and luteinizing hormone is involved in ovulation and testosterone production.

Why other options are wrong:
- Option A (Prolactin): Incorrect because prolactin is involved in milk production, not water reabsorption.
- Option B (Oxytocin): Incorrect because oxytocin is involved in uterine contractions and milk ejection, not water reabsorption in the kidneys.
- Option D (Luteinising hormone): Incorrect because luteinizing hormone is involved in ovulation and testosterone production, not water reabsorption.

Key Concepts:
- Water reabsorption in the nephron
- Function of vasopressin (ADH)

Memory Aids:
- ADH = Anti-Diuretic Hormone (prevents diuresis, i.e., water loss)

Quick Tips:
- Remember that vasopressin acts on the kidneys to regulate water balance.

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Glucagon is secreted by

View answer and explanation

Correct option: C

α-cells of islets of Langerhans

Option C (α-cells of islets of Langerhans) is correct because glucagon is secreted by alpha cells of the islets of Langerhans in the pancreas.

Solution approach

Correct Answer + Core Reason: α-cells of islets of Langerhans. Glucagon is secreted by alpha cells.

Step-by-Step Solution:

Step 1: Recall the endocrine functions of the pancreas.

Step 2: Identify the cells within the islets of Langerhans.

Step 3: Remember that alpha cells secrete glucagon and beta cells secrete insulin.

Step 4: Conclude that glucagon is secreted by alpha-cells of the islets of Langerhans.

Why other options are wrong:
- Option A: Adrenal medulla secretes epinephrine and norepinephrine.
- Option B: β-cells of islets of Langerhans secrete insulin.
- Option D: Adrenal cortex secretes corticosteroids (e.g., cortisol) and mineralocorticoids (e.g., aldosterone).

Key Concepts:
- Glucagon
- Islets of Langerhans
- Alpha cells
- Beta cells
- Pancreas

Memory Aids:
- Alpha cells: A = Glucagon
- Beta cells: B = Insulin

Quick Tips:
- Remember the specific hormones secreted by different cells in the pancreas.

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The function of pineal body is to

View answer and explanation

Correct option: D

All of the above

Option D (All of the above) is correct because the pineal gland influences skin pigmentation, sexual behavior, and the timing of puberty through melatonin secretion.

Solution approach

Correct Answer + Core Reason: All of the above. The pineal gland influences skin color, sexual behavior, and puberty.

Step-by-Step Solution:

Step 1: Recall the functions of the pineal gland.

Step 2: The pineal gland secretes melatonin, which affects:
- Skin color: Melatonin can lighten skin color.
- Sexual behavior: Melatonin can influence sexual development and behavior.
- Puberty: Melatonin plays a role in regulating the onset of puberty.

Step 3: Therefore, all the listed functions are associated with the pineal gland.

Why other options are wrong:
- Option A: While the pineal gland does influence skin color, it's not the only function.
- Option B: While the pineal gland does influence sexual behavior, it's not the only function.
- Option C: While the pineal gland does regulate the period of puberty, it's not the only function.

Key Concepts:
- Pineal gland functions
- Melatonin effects

Memory Aids:
- Pineal gland = multiple functions (skin, sex, puberty).

Quick Tips:
- Remember that the pineal gland has diverse effects due to melatonin's widespread influence.

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Thymosin is responsible for

View answer and explanation

Correct option: C

Increased production of T-lymphocytes

Option C (Increased production of T-lymphocytes) is correct because thymosin promotes the differentiation and maturation of T-lymphocytes, which are crucial for cell-mediated immunity.

Solution approach

Correct Answer + Core Reason: Increased production of T-lymphocytes. Thymosin promotes T-lymphocyte production.

Step-by-Step Solution:

Step 1: Recall the function of thymosin.

Step 2: Thymosin is a hormone secreted by the thymus gland.

Step 3: Thymosin stimulates the differentiation and proliferation of T-lymphocytes.

Step 4: T-lymphocytes are essential for cell-mediated immunity.

Why other options are wrong:
- Option A: Raising the blood sugar level: This is the function of hormones like glucagon and epinephrine.
- Option B: Raising blood $Ca$ level: This is the function of parathyroid hormone (PTH).
- Option D: Decrease in blood RBC: This is not a function of thymosin.

Key Concepts:
- Thymosin
- T-lymphocytes
- Cell-mediated immunity

Memory Aids:
- Thymosin = T-cells

Quick Tips:
- Know the functions of different hormones.

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