1. The acidic medium of gastric juice along with an enzyme Pepsin breaks the proteins down into smaller parts known as _____?
[A] Peptides
[B] Peptones
[C] Peptose
[D] Amino Acids
Show Answer
Correct Answer: B [Peptones]
Notes:
The acidic medium of gastric juice and the enzyme pepsin break down proteins into smaller parts known as peptones. Pepsin is the main enzyme involved in protein digestion. It breaks down proteins into smaller peptides and amino acids that can be easily absorbed in the small intestine.
The gastric juice contains hydrochloric acid, which helps maintain the pH in the range of 1.5 to 2.5. This pH range is very acidic and is necessary for optimum activity of pepsin. The hydrochloric acid converts inactive enzymes (zymogens) into active enzymes.
The gastric glands in the stomach secrete the enzyme pepsin. When pepsinogen is released into the stomach and mixed with gastric juice, it is converted into pepsin.
2. Hepatitis A which is the most common cause of jaundice in young people is an infection of liver by ________?
[A] Bacteria
[B] Virus
[C] Amoeba
[D] Prortozoan
Show Answer
Correct Answer: B [Virus]
Notes:
Hepatitis A which is the most common cause of jaundice in young people is an infection of liver by virus. It is transmitted through ingestion of contaminated food and water or through direct contact with an infectious person.
3. Among typhoid, hysteria, measles & influenza which is / are not contagious disease(s)?
[A] Hysteria only
[B] Hysteria & Measles
[C] Hysteria, Typhoid & Measles
[D] All are contagious diseases
Show Answer
Correct Answer: A [Hysteria only]
Notes:
Among typhoid, hysteria, measles & influenza, only Hysteria is not a contagious disease. A contagious disease is a subset category of transmissible diseases, which are transmitted to other persons.
4. Which component in light causes suppression of melatonin produced by the pineal gland?
[A] Red
[B] Blue
[C] Green
[D] Indigo
Show Answer
Correct Answer: B [Blue]
Notes:
Blue component in light causes suppression of melatonin produced by the pineal gland. Melatonin regulates the sleep–wake cycle. Natural levels of melatonin in the blood are highest at night.
5. It has been demonstrated by the scientists that, certain wines such as Red Wine posses health benefits because they contain antioxidants, which work in the body as Free Radical Scavengers and slow the oxidation of other molecules by capturing the free radicals. Which among the following is the most common antioxidant found in Red Wine?
[A] Catechin
[B] Tetrodotoxin
[C] Polyphenol
[D] Tocopherol
Show Answer
Correct Answer: C [Polyphenol]
Notes:
The most common antioxidant found in Red Wine is Polyphenol. It has been demonstrated by the scientists that, certain wines such as Red Wine posses health benefits because they contain antioxidants, which work in the body as Free Radical Scavengers and slow the oxidation of other molecules by capturing the free radicals.
6. Which of following is the primary photosynthetic pigment?
[A] Chlorophyll-b
[B] Carotenoid
[C] Chlorophyll-a
[D] Anthocyanin
Show Answer
Correct Answer: C [Chlorophyll-a]
Notes:
Chlorophylla-a is the primary pigment for photosynthesis in plants. Chlorophyll a is a specific form of chlorophyll used in oxygenic photosynthesis. It absorbs most energy from wavelengths of violet-blue and orange-red light.
7. Which of the following is the later (Second) formed primary xylem elements?
[A] Xylem fibres
[B] Metaxylem
[C] Xylem parenchyma
[D] Protoxylem
Show Answer
Correct Answer: B [Metaxylem]
Notes:
Metaxylem is the part of the primary xylem that differentiates after the protoxylem and that is distinguished typically by broader tracheids and vessels with pitted or reticulate walls.
8. Which of the following is/are found in plant cells but not in those of animals? (UPSC Prelims 1987)
[A] Plastid & Cellular wall
[B] Chromosome
[C] Mitochondria & Golgi apparatus
[D] Cell wall & lysozyme
Show Answer
Correct Answer: A [Plastid & Cellular wall]
Notes:
Plant cells have a cell wall, chloroplasts and other specialized plastids, and a large central vacuole, which are not found within animal cells.
9. Why man cannot digest cellulose whereas cows can do so? (UPSC Prelims 1992)
[A] Their gut contains certain bacteria capable of digesting cellulose
[B] They have a many-chambered stomach
[C] They have efficient grinding molars
[D] They produce enzyme cellulose which can digest cellulose
Show Answer
Correct Answer: A [Their gut contains certain bacteria capable of digesting cellulose]
Notes:
Unlike cows for example don’t have the necessary bacteria in their intestines that make the enzymes necessary to breakdown the 1-4 beta glucose bonds. So we cannot break down cellulose into its constituent glucose molecules as we do with starch.
10. Fat present below the skin surface in our body, acts as a barrier against which of the following losses? (UPSC Prelims 1996)
[A] Loss of heat from the body
[B] loss of essential body fluids
[C] loss of salts from the body
[D] entry of harmful micro-organisms from the environment
Show Answer
Correct Answer: A [Loss of heat from the body]
Notes:
Adipose tissue that’s fat cells which are under the skin act as barrier to loss of the heat from the body and it protects the skin from entering of highly reactive UV rays of the sun. Fat present below the skin surface in our body, act as an insulator against loss of heat from the body. The deposited fat works as barrier, which prevents loss of heat.
