CSS - PMS - CCE - PCS - General Science
Vitamins
Vitamin D belongs chemically to a group of compounds called:
A. Secosteroids
B. Amino acids
C. Purines
D. Polysaccharides
Correct Answer: A
A is correct because vitamin D compounds are secosteroids derived from steroid precursors.
CSS - PMS - CCE - PCS - General Science
Vitamins
Which of the following is a rich animal source of preformed vitamin A?
A. Liver
B. White rice
C. Refined sugar
D. Table salt
Correct Answer: A
A is correct because liver is rich in retinol, the preformed animal form of vitamin A.
CSS - PMS - CCE - PCS - General Science
Vitamins
Excessive intake of preformed vitamin A during pregnancy is especially concerning because it may be:
A. Teratogenic
B. Anticoagulant only
C. A cause of scurvy
D. A cause of beriberi
Correct Answer: A
A is correct. High-dose preformed vitamin A and retinoids can cause fetal malformations, so excess intake in pregnancy is avoided.
CSS - PMS - CCE - PCS - General Science
Vitamins
Which vitamin is essential for normal epithelial differentiation and maintenance?
A. Vitamin A
B. Vitamin B12
C. Vitamin C
D. Vitamin K
Correct Answer: A
A is correct because retinoic acid regulates gene transcription involved in epithelial growth and differentiation.
CSS - PMS - CCE - PCS - General Science
Vitamins
Keratomalacia may occur in severe deficiency of:
A. Vitamin A
B. Vitamin B1
C. Vitamin B3
D. Vitamin K
Correct Answer: A
A is correct because severe vitamin A deficiency can soften and damage the cornea, producing keratomalacia.
CSS - PMS - CCE - PCS - General Science
Vitamins
Bitot spots are a clinical sign of deficiency of:
A. Vitamin A
B. Vitamin D
C. Vitamin E
D. Vitamin B6
Correct Answer: A
A is correct. Bitot spots are foamy conjunctival lesions associated with vitamin A deficiency.
CSS - PMS - CCE - PCS - General Science
Vitamins
Xerophthalmia is classically linked with deficiency of:
A. Vitamin A
B. Vitamin B12
C. Vitamin C
D. Vitamin K
Correct Answer: A
A is correct because vitamin A deficiency causes dryness of the conjunctiva and cornea, which may progress to xerophthalmia and keratomalacia.
CSS - PMS - CCE - PCS - General Science
Vitamins
Night blindness is most strongly associated with deficiency of:
A. Vitamin A
B. Vitamin B2
C. Vitamin E
D. Vitamin K
Correct Answer: A
A is correct because vitamin A is required for retinal formation and dark adaptation. Deficiency can cause night blindness and xerophthalmia.
CSS - PMS - CCE - PCS - General Science
Vitamins
Which pigment in carrots is an important provitamin A carotenoid?
A. Beta-carotene
B. Lycopene
C. Anthocyanin
D. Chlorophyll
Correct Answer: A
A is correct because beta-carotene can be converted to vitamin A in the body. Lycopene is a carotenoid but is not an important provitamin A source.
CSS - PMS - CCE - PCS - General Science
Vitamins
The active aldehyde form of vitamin A involved in vision is:
A. Retinal
B. Retinol
C. Retinoic acid
D. Calcitriol
Correct Answer: A
A is correct. Retinal combines with opsin to form visual pigments such as rhodopsin. Retinol is the alcohol form, retinoic acid regulates gene expression, and calcitriol is active vitamin D.
CSS - PMS - CCE - PCS - General Science
Vitamins
Which fat-soluble vitamin is stored in large amounts in the liver and is essential for vision?
A. Vitamin A
B. Vitamin B1
C. Vitamin C
D. Vitamin B2
Correct Answer: A
A is correct because vitamin A is stored mainly in the liver and is required for the visual cycle, epithelial integrity and immunity.
CSS - PMS - CCE - PCS - General Science
Vitamins
Which group contains only water-soluble vitamins?
A. A, D, E and K
B. B-complex vitamins and vitamin C
C. A, C, E and K
D. D, K and B12 only
Correct Answer: B
B is correct because the B-complex family and vitamin C are water soluble. Vitamins A, D, E and K are fat soluble.
CSS - PMS - CCE - PCS - General Science
Vitamins
Which group contains only fat-soluble vitamins?
A. B1, B2, B6, B12
B. A, D, E, K
C. C, B1, B9, B12
D. A, C, D, B6
Correct Answer: B
B is correct: vitamins A, D, E and K are fat soluble. The B-complex vitamins and vitamin C are water soluble.
CSS - PMS - CCE - PCS - General Science
Vitamins
Vitamins are best described as:
A. Organic micronutrients required in small amounts
B. Inorganic salts needed in kilograms
C. Energy-yielding macronutrients
D. Structural proteins only
Correct Answer: A
A is correct because vitamins are organic micronutrients needed in small quantities for normal metabolism. B describes minerals. C is wrong because vitamins do not themselves supply significant energy. D is wrong because vitamins are not structural proteins.
CSS - PMS - CCE - PCS - General Science
Organs
Which organ produces the hormone renin as part of blood pressure regulation?
A. Kidney
B. Liver
C. Spleen
D. Pancreas
Correct Answer: A
Juxtaglomerular cells of the kidney secrete renin, initiating the renin-angiotensin system.
CSS - PMS - CCE - PCS - General Science
Organs
Which organ receives feces immediately before defecation?
A. Rectum
B. Stomach
C. Jejunum
D. Gallbladder
Correct Answer: A
The rectum stores feces before their elimination through the anal canal.
CSS - PMS - CCE - PCS - General Science
Organs
Which organ contains the ileocecal valve at its junction with another digestive segment?
A. Small intestine
B. Stomach
C. Esophagus
D. Gallbladder
Correct Answer: A
The ileocecal valve lies between the terminal ileum and cecum.
CSS - PMS - CCE - PCS - General Science
Organs
Which organ contains the pyloric sphincter?
A. Stomach
B. Kidney
C. Liver
D. Heart
Correct Answer: A
The pyloric sphincter regulates passage of stomach contents into the duodenum.
CSS - PMS - CCE - PCS - General Science
Organs
Which organ has a major role in both mechanical and chemical digestion?
A. Stomach
B. Spleen
C. Bladder
D. Thymus
Correct Answer: A
The stomach mechanically churns food and chemically digests it with acid and enzymes.
CSS - PMS - CCE - PCS - General Science
Organs
Which organ uses peristalsis to move food toward the stomach?
A. Esophagus
B. Trachea
C. Ureter
D. Aorta
Correct Answer: A
Coordinated smooth muscle contractions called peristalsis move food through the esophagus.