Consider the following statements regarding mutations:

1. A silent mutation is a change in the DNA sequence that does not change the amino acid sequence of the protein.

2. Missense mutations always result in the complete loss of protein function.

3. Frameshift mutations typically occur due to the insertion or deletion of nucleotides in numbers not divisible by three.

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#Question id: 34146

#Biochemistry

I. Human pituitary prolactin has considerable structural similarity to human growth hormone and human chorionic somatomammotropin (hCS).

II. Structurally similar prolactin are secreted by the endometrium and by the placenta.

III. prolactin secretion is increased during pregnancy, reaching a peak at the time of parturition.

IV. The human prolactin receptor resembles the oxytocin receptor.

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#Question id: 34147

#Biochemistry

Which of the following statements not CORRECT regarding the mechanism and reproductive role of prolactin during lactation?

TLS Online TPP Program

#Question id: 34148

#Biochemistry

Assertion (A): Prolactin stimulates the synthesis of casein and lactalbumin during lactation without acting directly on the cell nucleus.

Reason (R): The action of prolactin is dependent on intact microtubules, suggesting involvement of cytoplasmic transport or signaling components.

Choose the correct option:

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#Question id: 34154

#Biochemistry

Which organelle is particularly abundant in adrenal cortex cells due to its role in steroid hormone synthesis?

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#Question id: 34163

#Biochemistry

Which of the following represents the correct sequential pathway for aldosterone synthesis from cholesterol, based on the enzyme-catalyzed steps?

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#Question id: 34167

#Biochemistry

I. The adrenal medulla does not regenerate, but when the inner two zones of the cortex are removed, a new ZF and ZR regenerate from glomerular cells attached to the capsule.

II. Immediately after hypophysectomy, the ZF and ZR begin to atrophy, whereas the ZG is unchanged because of the action of angiotensin II on this zone. 

III. The ability to secrete aldosterone and conserve Na+ is normal for some time after hypophysectomy, but in longstanding hypopituitarism, aldosterone deficiency may develop, apparently because of the absence of a pituitary factor that maintains the responsiveness of the zona glomerulosa.