Biology (Part-I) (UPSC)

Total Questions: 50

11. Which one of the following organisms can serve as a biofertilizer for rice crop? [2000]

(a) Blue-green algae
(b) Rhizobium sp.
(c) Mycorrhizal fungi
(d) Azotobacter sp.

Correct Answer: (a) Blue-green algae

Solution:Blue green algae is used as a biofertilizer in rice crop. Blue green algae has the nitrogen fixing ability which enhances the production of rice.

12. Phytotron is a facility to : [2000]

(a) grow plants under disease-free conditions
(b) conserve endangered species of plants
(c) grow plants under controlled conditions
(d) induce mutations

Correct Answer: (c) grow plants under controlled conditions

Solution:Phytotron is enclosed green house or laboratory where plants are grown under strict controlled environmental conditions to study interaction of plant and environment.

13. Soft drinks such as colas contain significant quantities of: [2000]

(a) caffeine
(b) nicotine
(c) tannin
(d) renin

Correct Answer: (a) caffeine

Solution:Cocoa contains caffeine, carbonated water, glucose-fructose, kola extract and caramel colour.

14. Canola refers to special type of oil seed mustard varieties bred for human consumption. The main characteristic of these varieties is that the : [2000]

(a) seeds have very high oil content
(b) oil is rich in unsaturated fatty acids
(c) oil has long shelf-life
(d) oil has very low erucic acid content

Correct Answer: (b) oil is rich in unsaturated fatty acids

Solution:Canola refers to both an edible oil (also known as canola oil) produced from the seed of any of several varieties of the Brassicaceae family of plants, and to those plants, namely a cultivar of Brassica napus L., Brassica rapa subsp. oleifera, syn. B. campestris L. or Brassica juncea. To be called canola, it must contain less than 2% erucic acid and less than 30 micromoles glucosinolates.

15. Which organelle in the cell, other than nucleus contains DNA? [2001]

(a) Centriole
(b) Golgi apparatus
(c) Lysosome
(d) Mitochondrion

Correct Answer: (d) Mitochondrion

Solution:DNA is also found in mitochondria other than nucleus. The DNA is called mitochondrial DNA.

16. "Athlete's Foot" is a disease' caused by : [2001]

(a) Bacteria
(b) Fungus
(c) Protozoan
(d) Nematode

Correct Answer: (b) Fungus

Solution:Athlete's Foot disease is caused by parasitic fungus of genus Trichophyton. Scaling, flaking and itching of affected areas are the symptoms of this disease. This disease transmitted in moist areas where people walk bare foot.

17. Epiphytes are plants which depend on other plants for : [2001]

(a) food
(b) mechanical support
(c) shade
(d) water

Correct Answer: (b) mechanical support

Solution:An epiphyte is a plant normally grows on another plant for support. It is non parasitic, but uses the host plant for support. A plant such as tropical orchid or staghorn fern, that grows on another plant upon which it depends for mechanical support but not for nutrients.

18. In a bisexual flower, if androecium and gynoecium mature at different times, the phenomenon is known as : [2002]

(a) dichogamy
(b) herkogamy
(c) heterogamy
(d) monogamy

Correct Answer: (a) dichogamy

Solution:In bisexual flower, the male and female flowers (androecium and gynoecium) mature at different times to avoid self-fertilization. It is called dichogamy.

19. Consider the following plants : [2003]

1. Bougainvillea

2. Carnations

3. Cocoa

4. Grapes

Which of these plants are propagated by stem cuttings?

(a) 1 and 2
(b) 2, 3 and 4
(c) 1, 3 and 4
(d) 1, 2, 3 and 4

Correct Answer: (d) 1, 2, 3 and 4

Solution:Propagation by stem cuttings is a common method of asexual reproduction in plants, where a portion of the stem with at least one node and one or more leaves is cut from the parent plant and rooted to form a new individual plant. The new plant will have the same genetic makeup as the parent plant and will exhibit similar characteristics, making this method useful for maintaining desirable traits of a plant. Bougainvillea, carnations, grapes, and cocoa are all plants that can be propagated by stem cuttings.

20. Consider the following statements: [2003]

1. The common blue green algae, Spirogyra and Ulothrix, are found in both fresh water ponds and oceans.

2. The Chameleon can look ahead with one eye, and at the same time look behind with another.

Which of these statements is/are correct?

(a) Only 1
(b) Only 2
(c) Both 1 and 2
(d) Neither 1 nor 2

Correct Answer: (c) Both 1 and 2

Solution:The common blue green algae Spirogyra and Ulothrix are found in both fresh water ponds and oceans. Algae species like Spirogyra and Ulothrix are generally found in fresh water environments.

However, the statement declares they are found in oceans as well, and without specific supporting evidence, this claim is debatable. But the answer assumes it as true.

The chameleon can look ahead with one eye, and at the same time look behind with another. This is accurate, as chameleons have unique eyes that can swivel independently, allowing them to look in two completely different directions at once.

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