Nokea
Which colour change is observed when water is added to anhydrous cobalt(II) chloride?
- A. blue to white
- B. blue to pink
- C. white to blue
- D. pink to blue
Correct Answer: B
Rationale: The correct answer is B: blue to pink. Anhydrous cobalt(II) chloride is blue, and when water is added, it forms a pink hexahydrate complex. This color change occurs because water molecules replace the chloride ions in the crystal lattice, resulting in the formation of the pink complex. Choice A (blue to white) is incorrect because the addition of water does not change the color to white. Choice C (white to blue) is incorrect as anhydrous cobalt(II) chloride is blue to begin with. Choice D (pink to blue) is incorrect as the addition of water causes the color change from blue to pink, not the other way around.
You may also like to solve these questions
What medication is used with thyrotoxicosis to block the effects of the sympathetic nervous stimulation of the thyroid hormones?
- A. Potassium iodide
- B. Propylthiouracil (PTU)
- C. Atenolol (Tenormin)
- D. Radioactive iodine (RAI)
Correct Answer: C
Rationale: Atenolol is a beta-blocker that helps control the sympathetic nervous system effects of thyrotoxicosis, such as tachycardia and hypertension.
Which gland is often referred to as the 'master gland'?
- A. Pituitary
- B. Thyroid
- C. Thymus
- D. Hypothalamus
Correct Answer: A
Rationale: The pituitary gland is often referred to as the 'master gland' because it plays a crucial role in regulating other endocrine glands in the body. It secretes hormones that control various bodily functions, such as growth, reproduction, and metabolism. The other choices, thyroid, thymus, and hypothalamus, are important glands as well, but they do not have the same broad control over the endocrine system as the pituitary gland. The thyroid regulates metabolism, thymus is involved in immune function, and hypothalamus regulates body temperature, hunger, and thirst. However, none of these glands have the overall regulatory function and influence on other glands as the pituitary gland does.
The posterior pituitary gland stores and secretes
- A. oxytocin and antidiuretic hormone
- B. human growth hormone and thyroid stimulating hormone
- C. prolactin and follicle stimulating hormone
- D. glucocorticoids and androgens
Correct Answer: A
Rationale: Step-by-step rationale:
1. The posterior pituitary gland stores oxytocin and antidiuretic hormone (ADH).
2. Oxytocin is responsible for uterine contractions and milk ejection.
3. ADH regulates water balance by controlling urine concentration.
4. These hormones are produced in the hypothalamus and released from the posterior pituitary.
5. Choice A is correct as it accurately identifies the hormones stored and secreted by the posterior pituitary.
Summary:
- Choice B is incorrect because human growth hormone and thyroid stimulating hormone are not stored or secreted by the posterior pituitary.
- Choice C is incorrect because prolactin and follicle stimulating hormone are produced by the anterior pituitary.
- Choice D is incorrect because glucocorticoids and androgens are not stored or secreted by the posterior pituitary.
Which of the following is a protein hormone?
- A. Oxytocin
- B. Insulin
- C. TSH
- D. ADH
Correct Answer: B
Rationale: The correct answer is B: Insulin. Insulin is a protein hormone produced by the pancreas that regulates blood sugar levels. Proteins are large molecules made up of amino acids, and insulin fits this definition. Oxytocin (A) is a peptide hormone, not a protein. TSH (C) and ADH (D) are both peptide hormones as well, not proteins. In summary, insulin is the only option that fits the criteria of being a protein hormone.
Identify the glands associated with these hormones: gonadotropins, aldosterone, and epinephrine.
- A. Adenohypophysis, neurohypophysis, pancreas
- B. Adenohypophysis, anterior pituitary, adrenal cortex
- C. Adenohypophysis, posterior pituitary, adrenal medulla
- D. Anterior pituitary, adrenal cortex, adrenal medulla
Correct Answer: D
Rationale: The correct answer is D because gonadotropins are secreted by the anterior pituitary gland, aldosterone is produced by the adrenal cortex, and epinephrine is released by the adrenal medulla. The anterior pituitary gland secretes gonadotropins such as FSH and LH. The adrenal cortex synthesizes aldosterone, which regulates sodium and potassium balance. The adrenal medulla produces epinephrine, involved in the fight or flight response. Choices A and C are incorrect because they do not match the correct associations of the hormones with their respective glands. Choice B is incorrect as the adrenal cortex and adrenal medulla are not part of the anterior pituitary gland.