201. Assertion: Androgens promote development of male secondary sexual characteristics.
Reason: Androgens are synthesised mainly by thyroid follicular cells.
ⓐ. Both Assertion and Reason are true, and Reason correctly explains Assertion
ⓑ. Both Assertion and Reason are true, but Reason does not explain Assertion
ⓒ. Assertion is true, but Reason is false
ⓓ. Assertion is false, but Reason is true
Correct Answer: Assertion is true, but Reason is false
Explanation: The assertion is true. Testicular androgens promote characteristic male changes that include muscular growth, facial and axillary hair and a low-pitched voice. The reason is false because thyroid follicular cells synthesise the iodothyronines \(T_3\) and \(T_4\), not androgens. In the testis, androgens are produced mainly by Leydig cells situated between seminiferous tubules. The source error prevents the reason from explaining the valid assertion. This distinction links hormone action to the correct endocrine cell population and avoids confusing two unrelated glandular tissues merely because both release hormones into the circulation. A shared topic alone is insufficient; the Reason must account for the event stated in the Assertion. In evaluating the statements, both truth values must be judged independently before the explanatory link between the statements is tested.
202. Choose the sequence that correctly orders the events in a pituitary-testicular pathway.
P. Androgens support spermatogenesis and male reproductive functions.
Q. LH stimulates Leydig cells.
R. Testosterone and other androgens are released.
S. LH is secreted from pars distalis.
ⓐ. \(S\rightarrow Q\rightarrow R\rightarrow P\)
ⓑ. \(Q\rightarrow S\rightarrow P\rightarrow R\)
ⓒ. \(S\rightarrow R\rightarrow Q\rightarrow P\)
ⓓ. \(R\rightarrow Q\rightarrow S\rightarrow P\)
Correct Answer: \(S\rightarrow Q\rightarrow R\rightarrow P\)
Explanation: The pathway begins in pars distalis, which releases LH into the circulation. LH reaches the testis and stimulates Leydig cells. These interstitial cells then synthesise and secrete androgens, principally testosterone. The androgens act on reproductive tissues and participate in regulation of spermatogenesis and other male functions. Each stage depends on the previous one, giving the sequence \(S\rightarrow Q\rightarrow R\rightarrow P\). Androgen release cannot occur as the stated LH-dependent response before Leydig-cell stimulation. The sequence connects a pituitary gonadotrophin with a testicular endocrine cell, its hormonal product and the downstream biological effects. The correct order preserves both the starting point and the specified direction of movement or regulation. The sequence is biologically ordered since each stage establishes a condition needed for the next. The stated ordering criterion must be followed consistently from the initial event to the final outcome.
203. FSH secretion remains normal in an adult male, but Leydig cells can no longer produce androgens. The most likely effect on sperm formation is:
ⓐ. normal spermatogenesis because FSH acts independently
ⓑ. enhanced spermatogenesis after androgen loss
ⓒ. replacement of androgen action by prolactin
ⓓ. impaired spermatogenesis despite available FSH
Correct Answer: impaired spermatogenesis despite available FSH
Explanation: Normal spermatogenesis depends on the combined influence of FSH and androgens. The described condition preserves FSH secretion but removes androgen production through failure of Leydig cells. One required component of the regulatory combination is consequently absent, so sperm formation is expected to be impaired. This condition complements a situation in which FSH is missing while androgens remain available; in either case, loss of one cooperating signal weakens the process. Prolactin does not replace testicular androgen action in spermatogenesis. The prediction follows from recognising that FSH is necessary but is not described as independently sufficient under complete androgen deficiency. The decisive clue is the full biological relationship, not merely the occurrence of a familiar endocrine term.
204. Assess the statements given for androgen effects on the central neural system.
I. They influence male libido.
II. They contribute to male sexual behaviour.
III. Their behavioural action occurs only through direct stimulation of renal tubules.
IV. Their central effects are distinct from their anabolic actions on peripheral tissues.
ⓐ. I and III only
ⓑ. I, II and IV only
ⓒ. II, III and IV only
ⓓ. I, II, III and IV
Correct Answer: I, II and IV only
Explanation: Androgens act not only on reproductive organs and body tissues but also on the central neural system. Through this neural influence, they contribute to male libido and sexual behaviour, making statements I and II valid. Statement III assigns the effect to renal tubules, which are unrelated to the central behavioural pathway. Statement IV is also valid: influence on behaviour is a different functional layer from anabolic effects such as support of synthetic metabolic pathways and muscular development. The valid combination shows that one hormone class can act on several target systems and produce reproductive, behavioural and metabolic outcomes without those effects being identical. When the listed claims are evaluated, the final combination reflects complete biological consistency across the listed statements rather than recognition of one familiar term.
205. Neural tissue involved in male sexual behaviour is maintained under controlled conditions. Addition of an androgen alters the activity of the responsive preparation, while an otherwise identical preparation that cannot respond to the hormone shows no change. The strongest inference is:
ⓐ. androgens influence behaviour only by changing blood-glucose concentration
ⓑ. the neural response is unrelated to androgen recognition by target cells
ⓒ. androgen-responsive neural targets can contribute to male libido and behaviour
ⓓ. all living neural preparations must respond equally to the same androgen concentration
Correct Answer: androgen-responsive neural targets can contribute to male libido and behaviour
Explanation: The experiment compares responsive and non-responsive neural preparations exposed to the same androgen. A change occurs only where the tissue can respond to the hormone, linking androgen action with activity in a neural target involved in sexual behaviour. The result supports the relation between central neural-system action, libido and male behaviour. The evidence is limited but clear: effective androgen recognition in neural tissue is required for the observed behavioural-pathway response. The controlled response links androgen recognition in neural tissue with regulation of male sexual behaviour while leaving the testicular source of the hormone distinct. Equal androgen exposure with different responses shows that target-cell recognition, not hormone concentration alone, determines the neural effect.
206. Three effects are measured after androgen action is reduced.
| Effect | Observed change |
|---|
| Protein and carbohydrate synthetic pathways | Reduced support |
| Muscular development | Reduced |
| Red-blood-cell formation | Reduced |
The data identify loss of which combined androgen functions?
ⓐ. Antidiuretic and mineralocorticoid actions
ⓑ. Hyperglycaemic and anti-inflammatory actions
ⓒ. Melanocyte-stimulating and diurnal actions
ⓓ. Anabolic and erythropoiesis-supporting actions
Correct Answer: Anabolic and erythropoiesis-supporting actions
Explanation: Support of synthetic protein and carbohydrate pathways represents an anabolic effect, since anabolic processes build or maintain complex biological materials. Reduced muscular development is consistent with loss of this synthetic influence. The decline in red-blood-cell formation identifies an erythropoietic effect as a second functional layer. Reading the observations together shows that androgens contribute both to tissue-building metabolism and to erythropoiesis. Antidiuretic and mineralocorticoid actions regulate renal water and ion handling, while hyperglycaemic, anti-inflammatory, pigmentation and rhythm effects belong to other hormone systems. The combined profile is best explained by reduced anabolic and erythropoietic androgen activity. The inference depends on synthesis across the columns rather than direct retrieval of one visible entry. Every column contributes to the inference, so a partly matching row cannot support the final conclusion. The strongest conclusion accounts for every reported observation without assuming changes in unmeasured pathways.
207. Androgen receptors in skeletal muscle and erythropoietic tissues are selectively blocked while testosterone secretion remains normal. The most likely outcome is:
ⓐ. increased muscle synthesis with reduced testosterone concentration
ⓑ. reduced anabolic support and reduced red-blood-cell formation
ⓒ. increased thyroid activity with stronger erythropoiesis
ⓓ. loss of renal water conservation with unchanged tissue synthesis
Correct Answer: reduced anabolic support and reduced red-blood-cell formation
Explanation: The hormonal source remains functional, but the specified target tissues cannot respond normally. Androgens support anabolic pathways that contribute to muscular growth and also promote red-blood-cell formation. Receptor blockade in these tissues weakens both responses even if circulating testosterone remains within its normal range. The condition illustrates the difference between hormone availability and hormone effectiveness: a signal may be present yet fail to produce its physiological outcome when target recognition is disrupted. Thyroid activity and renal water conservation are governed through different endocrine pathways. The predicted pattern is a target-level loss of androgen-dependent anabolic and erythropoietic effects rather than reduced hormone synthesis. Following the pathway downstream from the altered step identifies the earliest affected response and any later consequence. At the relevant step in the sequence, locating the defect at synthesis, transport, receptor recognition or target response determines which parts of the pathway remain functional.
208. The testes and ovaries are placed in the same biological relationship category since both:
ⓐ. are primary sex organs that produce gametes and secrete hormones
ⓑ. are accessory glands that produce no reproductive cells
ⓒ. lie outside the abdominal cavity and secrete only peptide hormones
ⓓ. function exclusively as endocrine organs after puberty
Correct Answer: are primary sex organs that produce gametes and secrete hormones
Explanation: Testes and ovaries are the primary male and female sex organs, respectively. Each has a reproductive function through production of gametes and an endocrine function through secretion of sex hormones. The testes produce sperm and release androgens, while the ovaries produce ova and release estrogens and progesterone from different ovarian structures. They are not merely accessory organs, and neither is exclusively endocrine. Their anatomical positions also differ: the testes lie in the scrotal sacs outside the abdominal cavity, whereas the ovaries are paired organs within the abdominal-pelvic region. Their shared category is fixed by dual gamete-producing and hormone-secreting roles.
209. Use the ovarian arrangement described below. Two paired organs lie in the abdominal-pelvic region. Each contains developing follicles embedded within supporting stromal tissue. These organs:
ⓐ. produce only hormones and no reproductive cells
ⓑ. are pancreatic islets surrounded by exocrine tissue
ⓒ. are ovaries with reproductive and endocrine functions
ⓓ. are adrenal glands containing cortex and medulla
Correct Answer: are ovaries with reproductive and endocrine functions
Explanation: The described organs are paired, located in the abdominal-pelvic region and contain follicles within stromal tissue. These are defining structural features of the ovaries. Ovarian follicles are associated with development of female gametes and are important endocrine structures, particularly as sources of estrogens while they grow. The ovaries also produce progesterone through the corpus luteum after ovulation. Pancreatic islets occur within pancreatic tissue, while adrenal glands are organised into cortex and medulla. The spatial and structural clues identify ovaries as primary female sex organs that combine ovum production with endocrine secretion.
210. Read the statements on the ovaries.
I. They occur as a pair in the abdominal-pelvic region.
II. They produce ova and function as primary female sex organs.
III. Their tissue includes follicles and stroma.
IV. They are located in scrotal sacs outside the abdomen.
ⓐ. I and IV only
ⓑ. I, II and III only
ⓒ. II, III and IV only
ⓓ. I, II, III and IV
Correct Answer: I, II and III only
Explanation: The ovaries are paired primary female sex organs situated in the abdominal-pelvic region. They produce ova and also function as endocrine organs, making statements I and II valid. Structurally, ovarian tissue contains follicles and supporting stromal components, so statement III is also true. Statement IV describes the location of the testes rather than the ovaries. The valid combination integrates position, reproductive identity and internal organisation. These features also prepare the source distinction between growing follicles, which mainly produce estrogens, and the corpus luteum formed after ovulation, which mainly secretes progesterone. Qualifiers such as age, tissue location and secretory direction are decisive when forming the valid combination. When the listed claims are evaluated, a statement remains invalid when it assigns a correct effect to the wrong source or the correct source to the wrong target.
211. Arrange the ovarian events and their hormonal sources in the correct order.
P. A growing follicle becomes a major source of estrogen.
Q. FSH promotes follicular growth.
R. LH induces ovulation.
S. The ruptured follicle forms a corpus luteum.
T. Progesterone becomes the major secretion of the corpus luteum.
ⓐ. \(P\rightarrow Q\rightarrow R\rightarrow T\rightarrow S\)
ⓑ. \(Q\rightarrow R\rightarrow P\rightarrow S\rightarrow T\)
ⓒ. \(R\rightarrow Q\rightarrow P\rightarrow T\rightarrow S\)
ⓓ. \(Q\rightarrow P\rightarrow R\rightarrow S\rightarrow T\)
Correct Answer: \(Q\rightarrow P\rightarrow R\rightarrow S\rightarrow T\)
Explanation: FSH stimulates the growth and development of ovarian follicles, establishing the first step. A growing follicle is a major source of estrogens, so the estrogen-producing stage follows follicular growth. LH then acts on a mature Graafian follicle and induces ovulation. Only after that event can the ruptured follicle form a corpus luteum. The corpus luteum mainly secretes progesterone, whose ovarian source therefore appears after corpus-luteum formation rather than before it. The ordering follows both a structural change in the ovary and a change in the dominant hormonal source. Placing progesterone before formation of the corpus luteum would assign a product to a structure that has not yet formed. The resulting sequence is FSH-supported growth, growing-follicle estrogen, LH-induced ovulation, corpus-luteum formation and progesterone secretion.
212. Growing ovarian follicles are selectively removed before ovulation, while most stromal tissue remains viable. Estrogen output falls markedly. The strongest inference is:
ⓐ. growing follicles are the principal ovarian source of estrogens
ⓑ. ovarian stroma is the only source of progesterone before and after ovulation
ⓒ. the corpus luteum is the major estrogen source before it forms
ⓓ. estrogens are synthesised mainly by the pituitary gland
Correct Answer: growing follicles are the principal ovarian source of estrogens
Explanation: The experimental treatment removes the growing follicular population and leaves much of the remaining ovarian tissue viable. The marked decline in estrogen output links the missing structures with the hormone’s principal ovarian source. Since the experiment occurs before ovulation, a corpus luteum has not yet formed and cannot account for the earlier estrogen production. The pituitary releases gonadotrophins that regulate the ovary but is not the main source of ovarian estrogens. The evidence supports a source conclusion limited to the tested stage: growing ovarian follicles provide the major estrogen secretion before the postovulatory corpus-luteum phase. The stated qualifier limits the conclusion to the specified hormone, tissue and physiological condition.
213. Examine the ovarian source assignments.
| Row | Ovarian structure | Stage | Principal secretion |
|---|
| P | Growing follicle | Before ovulation | Estrogens |
| Q | Corpus luteum | After ovulation | Progesterone |
| R | Growing follicle | After its rupture | Mainly progesterone |
| S | Corpus luteum | Before ovulation | Mainly estrogen |
The completely valid rows are:
ⓐ. P and R only
ⓑ. Q and S only
ⓒ. P and Q only
ⓓ. R and S only
Correct Answer: P and Q only
Explanation: Row P places a growing ovarian follicle before ovulation and assigns estrogens as its principal secretion, which is the expected relation. Row Q places the corpus luteum after ovulation and associates it mainly with progesterone, so it is also valid. The remaining rows fail the stage-and-structure check. A follicle that has ruptured at ovulation subsequently forms the corpus luteum; describing that postovulatory progesterone source as an ordinary growing follicle makes R inconsistent. A corpus luteum cannot serve as a source before ovulation, since its formation follows rupture of the mature follicle; S is also inconsistent. The question is solved by checking structure, timing and secretion together, not by finding one familiar hormone name. The transition from growing follicle to corpus luteum explains the corresponding shift from a principal estrogen source to a principal progesterone source. That timing is essential to judging the two valid rows.
214. Assertion: Estrogens promote the growth and activity of female accessory reproductive organs and developing ovarian follicles.
Reason: Growing ovarian follicles are the principal ovarian source of estrogens.
ⓐ. Both Assertion and Reason are true, and Reason correctly explains Assertion
ⓑ. Both Assertion and Reason are true, but Reason does not explain Assertion
ⓒ. Assertion is true, but Reason is false
ⓓ. Assertion is false, but Reason is true
Correct Answer: Both Assertion and Reason are true, but Reason does not explain Assertion
Explanation: The assertion correctly describes physiological actions of estrogens on female reproductive tissues, including accessory organs and developing ovarian follicles. The reason is also true: growing ovarian follicles are a principal ovarian source of estrogens. However, identifying where a hormone is made does not establish the mechanism by which responsive tissues grow or become active. A causal explanation of the assertion would need to connect estrogen with its receptor-bearing target cells and their growth or functional response. The reason supplies a source fact, not that source-to-target mechanism. Both statements can be accepted independently, yet their relationship is not the explanatory relationship stated in the first choice. This is why the true–true, non-explanatory combination is appropriate, even though the two statements concern the same hormone.
215. Match each estrogen-related target or outcome with its corresponding action. A Column II entry is used once.
| Column I | Column II |
|---|
| P. Female accessory reproductive organs | 1. Development of typical female secondary traits |
| Q. Secondary sexual characteristics | 2. Influence on female sexual behaviour |
| R. Mammary glands | 3. Growth and physiological activity |
| S. Central neural-system-related response | 4. Development of mammary tissue |
ⓐ. P-1, Q-3, R-2, S-4
ⓑ. P-4, Q-2, R-3, S-1
ⓒ. P-3, Q-4, R-1, S-2
ⓓ. P-3, Q-1, R-4, S-2
Correct Answer: P-3, Q-1, R-4, S-2
Explanation: Estrogens promote growth and activity of female accessory reproductive organs, giving P-3. They support development of female secondary sexual characteristics, so Q-1 is appropriate. Mammary-gland development is another recognised estrogen effect, producing R-4. Estrogens also influence female sexual behaviour through effects that include central neural-system-related responses, completing S-2. The mapping separates reproductive-organ growth, secondary traits, mammary development and behaviour as distinct but coordinated outcomes of one hormone group. Treating them as interchangeable would hide the range of estrogen-responsive target systems. Each column entry is assigned through its specific endocrine relation, so the mapping remains unambiguous. A single misplaced entry changes the mapping even when the remaining associations appear familiar. Reading the table as a whole, source, target and physiological direction provide independent checks on the completed mapping.
216. Estrogen action is selectively reduced during female puberty, while progesterone production remains available. The most likely pattern is:
ⓐ. impaired development of female secondary traits and mammary tissue
ⓑ. increased growth of female accessory organs despite absent estrogen action
ⓒ. complete replacement of follicular development by progesterone
ⓓ. selective loss of renal water reabsorption and increased diuresis
Correct Answer: impaired development of female secondary traits and mammary tissue
Explanation: Estrogens support development of female secondary sexual characteristics and mammary glands and promote growth and activity of female accessory reproductive organs. Selective reduction of estrogen action during puberty is expected to weaken these developmental outcomes. The presence of progesterone does not make it a complete substitute for estrogen, since progesterone has a distinct major role in pregnancy support and mammary alveolar development. Renal water conservation belongs primarily to the ADH pathway. The changed condition tests overlapping but non-identical ovarian-hormone functions: availability of one ovarian hormone cannot fully reproduce the pubertal actions normally mediated by another. The conclusion follows by keeping the source, route, receptor-bearing target and physiological effect in one consistent relation.
217. After ovulation, the newly formed corpus luteum is damaged and progesterone secretion falls sharply. Estrogen secretion from other ovarian tissue continues. Which consequence is most directly expected?
ⓐ. Increased support of pregnancy with enhanced mammary alveolar formation
ⓑ. Complete loss of estrogen-dependent female secondary characteristics
ⓒ. Reduced support for pregnancy and impaired mammary alveolar development
ⓓ. Immediate failure of milk ejection despite normal uterine and duct contractions
Correct Answer: Reduced support for pregnancy and impaired mammary alveolar development
Explanation: The corpus luteum forms from the ruptured follicle after ovulation and principally secretes progesterone. Progesterone supports pregnancy and promotes formation of mammary-gland alveoli and milk secretion. Damage to the corpus luteum removes much of this postovulatory hormonal support even when estrogen continues to be produced elsewhere. The expected defect concerns progesterone-dependent pregnancy maintenance and mammary alveolar development rather than disappearance of every estrogen-mediated trait. Milk ejection is primarily an oxytocin-dependent contractile response and is distinct from progesterone’s effects on mammary structure and secretory preparation. The case highlights the functional transition from the estrogen-producing growing follicle to the progesterone-producing corpus luteum. A selective block produces a selective consequence; it does not justify loss of every function performed by the organ. With the other ovarian and pituitary functions preserved, the expected changes remain limited to progesterone-dependent support after corpus-luteum damage.
218. A pregnant individual has normal prolactin and oxytocin activity, but progesterone action is selectively blocked. Which change is most directly expected?
ⓐ. Increased formation of mammary alveoli with stronger pregnancy support
ⓑ. Reduced pregnancy support and impaired mammary alveolar development
ⓒ. Complete loss of milk ejection despite normal mammary contractions
ⓓ. Increased follicular estrogen secretion after corpus-luteum degeneration
Correct Answer: Reduced pregnancy support and impaired mammary alveolar development
Explanation: Progesterone is secreted mainly by the corpus luteum after ovulation. It supports pregnancy and acts on the mammary glands to promote formation of alveoli and milk secretion. Blocking progesterone action weakens these specific reproductive and mammary effects even when prolactin and oxytocin remain available. Prolactin is associated mainly with mammary-gland growth and milk formation, while oxytocin produces milk ejection through contraction of mammary structures. Neither hormone fully replaces progesterone’s role in maintaining pregnancy and preparing mammary alveolar tissue. The condition is a target-response defect rather than loss of the corpus luteum itself, so circulating progesterone may still be present but unable to produce its normal effects. The preserved variables act as controls, allowing the effect of the single changed condition to be interpreted without adding an unmentioned defect. A selective block produces a selective consequence; it does not justify loss of every function performed by the organ.
219. Identify the valid statements about progesterone.
I. The corpus luteum is its principal ovarian source after ovulation.
II. It supports the maintenance of pregnancy.
III. It promotes formation of mammary alveoli and milk secretion.
IV. It is the principal hormone causing milk ejection through mammary contraction.
ⓐ. I and IV only
ⓑ. II and III only
ⓒ. I, III and IV only
ⓓ. I, II and III only
Correct Answer: I, II and III only
Explanation: After ovulation, the ruptured follicle develops into the corpus luteum, which mainly secretes progesterone. The hormone supports pregnancy and contributes to mammary preparation by promoting alveolar formation and milk secretion. Statements I, II and III are consistent with this source-function relation. Statement IV assigns progesterone the contractile role of oxytocin. Milk ejection requires contraction of structures associated with the mammary ducts and is stimulated principally by oxytocin released from the posterior pituitary. Progesterone’s mammary effect concerns alveolar development and secretory preparation rather than the mechanical expulsion of already formed milk. The valid set consequently includes the first three statements while excluding the milk-ejection claim. On comparing the stated claims, the accepted set follows only after the truth of every statement is judged independently against the same endocrine relations.
220. Place the events linking ovulation with progesterone action in the correct sequence.
P. Progesterone supports pregnancy and mammary alveolar development.
Q. LH induces rupture of the mature Graafian follicle.
R. The ruptured follicle forms the corpus luteum.
S. The corpus luteum secretes progesterone.
ⓐ. \(Q\rightarrow R\rightarrow S\rightarrow P\)
ⓑ. \(R\rightarrow Q\rightarrow P\rightarrow S\)
ⓒ. \(Q\rightarrow S\rightarrow R\rightarrow P\)
ⓓ. \(S\rightarrow Q\rightarrow R\rightarrow P\)
Correct Answer: \(Q\rightarrow R\rightarrow S\rightarrow P\)
Explanation: LH first induces ovulation by causing rupture of the mature Graafian follicle. The remaining follicular tissue then develops into the corpus luteum. Once formed, the corpus luteum becomes the principal ovarian source of progesterone during the postovulatory stage. Progesterone subsequently supports pregnancy and promotes mammary alveolar development and milk secretion. Each stage depends on the preceding one, giving the order \(Q\rightarrow R\rightarrow S\rightarrow P\). Progesterone secretion cannot be assigned to the corpus luteum before that structure forms, and the corpus luteum itself arises only after follicular rupture. The sequence joins a pituitary signal, an ovarian structural transition, endocrine secretion and target-tissue effects. The pathway can be checked by tracing the direction of information flow through successive structures or events. Adjacent stages are distinguished by the anatomical or causal relation that connects them.
