Digestive System (Part-II)

21. How many ‘canine teeth’ does an adult human have? [S.S.C. Online Graduate Level (T-I) 10.06.2019 (Shift-III)]

(a) 8
(b) 6
(c) 3
(d) 4

Correct Answer: (d) 4

Solution:An adult human typically has four canine teeth: two in the upper jaw and two in the lower jaw. Canines are pointed teeth located next to the incisors, primarily used for tearing food.

22. What causes the mottling of the dental enamel ? [S.S.C. Online Graduate Level (T-I) 1.09.2016 (Shift-II)]

(a) High levels of chlorine in water.
(b) High levels of nitrate in the water.
(c) High levels of fluorides in the water.
(d) High levels of calcium in the water.

Correct Answer: (c) High levels of fluorides in the water.

Solution:Dental fluorosis, characterized by the mottling (discoloration and pitting) of dental enamel, is caused by excessive exposure to fluoride during tooth development (typically in childhood). While fluoride in optimal amounts strengthens enamel, too much can disrupt the mineralization process.

23. Incisors teeth are ______ . [S.S.C. Online MTS (T-I) 19.09.2017 (Shift-III)]

(a) To bite and gnaw
(b) to chew
(c) to grind
(d) for churning

Correct Answer: (a) To bite and gnaw

Solution:Incisors are the four front teeth in both the upper and lower jaws (total of 8 in an adult). They have a sharp, chisel-like edge and are primarily used for biting, cutting, and gnawing food.

24. Which is the longest part of the digestive system in the human body? [S.S.C. Online MTS (T-I) 21.08.2019 (Shift-III)]

(a) Pancreatic duct
(b) Small intestine
(c) Large intestine
(d) Oesophagus

Correct Answer: (b) Small intestine

Solution:Despite its name, the small intestine is the longest section of the digestive tract, typically measuring around 6-7 meters (20-23 feet) in an adult. Its coiled and folded structure allows it to fit within the abdominal cavity. The large intestine is shorter but has a wider diameter.

25. Bacterial decomposition of biological material under anaerobic condition is— [S.S.C. Online Graduate Level (T-I) 6.09.2016 (Shift-II)]

(a) Fermentation
(b) Fertilization
(c) Contamination
(d) Composting

Correct Answer: (a) Fermentation

Solution:Fermentation is another anaerobic (non oxygen-requiring) pathway for breaking down glucose, one that’s performed by many types of organisms and cells. In fermentation, the only energy extraction pathway is glycolysis, with one or two extra reactions tacked on at the end.

26. Which of the following has the highest protein content per gram? [S.S.C. Online Graduate Level (T-I) 4.06.2019 (Shift-III)]

(a) Apple
(b) Soyabean
(c) Wheat
(d) Groundnut

Correct Answer: (b) Soyabean

Solution:Soyabean has highest protein content among the given options i.e. 0.36 g/ one gram. Protein is a macro nutrient. Minimum quantity required per day is around 50 grams. Protein is used to make enzymes, hormones. Protein is an important building block of bones, muscles, cartilage, skin and blood.

27. The most extensive use of molasses after fermentation is for producing— [S.S.C. Online Graduate Level (T-I) 27.08.2016 (Shift-I)]

(a) Methanol
(b) Sugar
(c) Ethanol
(d) Sugarcane

Correct Answer: (c) Ethanol

Solution:Molasses, a byproduct of sugar refining, is rich in fermentable sugars. It is widely used as a substrate for industrial fermentation by yeast to produce ethanol (ethyl alcohol), which is used as a fuel, solvent, and in alcoholic beverages.

28. To which class do Oxydoreductases, transferases, and hydrolases belong? [S.S.C. Online CHSL (T-I) 30.01.2017 (Shift-III)]

(a) Hormones
(b) Enzymes
(c) Proteins
(d) Vitamins

Correct Answer: (b) Enzymes

Solution:Oxydoreductases, transferases, and hydrolases are all major classes of enzymes. Enzymes are biological catalysts, almost always proteins, that speed up biochemical reactions in living organisms. These classifications are based on the type of reaction they catalyze:

Oxydoreductases: Catalyze oxidation-reduction reactions.
Transferases: Catalyze the transfer of a functional group from one molecule to another.
Hydrolases: Catalyze hydrolysis reactions (breakdown of compounds using water).