1. Whch among the following are called scavengers of ecosystems?
[A] Bacteria
[B] Fungi & Bacteria
[C] Algae, Fungi & Bacteria
[D] None of the above
Show Answer
Correct Answer: B [Fungi & Bacteria]
Notes:
Fungi & Bacteria are called scavengers of ecosystems. Scavengers keep the ecosystem free of the bodies of dead animals, or carrion. They break down the dead organic material and recycle it into the ecosystem as nutrients.
2. 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.
3. The cells of all living biological matter are made of four major elements. The elements are:
[A] Carbon, Hydrogen, Oxygen and Phosphorous
[B] Carbon, Hydrogen, Oxygen and Nitrogen
[C] Carbon, Hydrogen, Oxygen and Sulphur
[D] Sodium, Chlorine, Potassium and Magnesium
Show Answer
Correct Answer: B [ Carbon, Hydrogen, Oxygen and Nitrogen]
Notes:
The four major elements are Carbon, Hydrogen, Oxygen and Nitrogen.
4. Which of the following branches of Biology is concerned with the effects of radiation on living organisms?
[A] Actinobiolgy
[B] Cryobiology
[C] Cytogenetics
[D] Aerobiology
Show Answer
Correct Answer: A [Actinobiolgy]
Notes:
Actinobiolgy is the branch of biology which studies the effects of radiation on organisms. Cryobiology involves study of life at Low temperatures; Cytogenetics involves Cytological basis of inheritance and Aerobiology deals with the studies of spores and micro organisms in air.
5. Which of the following is not a feature of organisms in the class Mammalia ?
[A] milk producing mammary glands
[B] cells with a membrane-bounded nucleus
[C] dorsal hollow nerve chord
[D] chitin in the cell membrane
Show Answer
Correct Answer: D [ chitin in the cell membrane ]
Notes:
Organisms in the class Mammalia all have milk producing mammary glands; cells with a membrane-bounded nucleus and a dorsal hollow nerve cord. Chitin in Cell Walls is the feature of Kingdom fungi.
6. Which part of the plant is used in making saffron spice?
[A] Stigma
[B] Sepal
[C] Petal
[D] Leaf
Show Answer
Correct Answer: A [Stigma]
Notes:
Stigma of the plant is used in making the saffron spices. In making the saffron spice, stigma of the plant is used. Stigma is the top of the centre part of a flower. It receives the pollen that allows it to form new seeds.
7. Why honey bees are called social insects? (UPSC Prelims 1982)
[A] They visit all flowers to collect nectar
[B] They live in large family groups
[C] They depend for their food upon other insects
[D] They move socially with other insects
Show Answer
Correct Answer: B [They live in large family groups]
Notes:
Social insects are highly evolved insects that engage in a variety of complex tasks not practiced by the multitude of solitary insects. Honey bees are social insects because they live together in large, well-organized family groups. A single honeybee cannot grow or survive by itself. The three distinct kinds of honeybees in a colony are queen, worker, and drone.
8. 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.
9. Which among the following is the name given to the ductless and secretory glands in the human body? (UPSC Prelims 1997)
[A] Endocrine glands
[B] Exocrine glands
[C] Salivary glands
[D] None of the above
Show Answer
Correct Answer: A [Endocrine glands]
Notes:
Ductless glands which are also known as internally secreting glands or endocrine glands secrete their products or hormones directly into the blood stream in response to instructions from the brain.
10. Which vitamin helps in the clotting of blood?
[A] Vitamin C
[B] Vitamin B
[C] Vitamin K
[D] Vitamin E
Show Answer
Correct Answer: C [Vitamin K]
Notes:
Vitamin K helps in the clotting of blood preventing excessive leakage of blood.
Extra info: Its name is derived from German which means Koagulationsvitamin.
