Biology Miscellaneous (Part-IV)

21. Mycorrhizal biotechnology has been used in rehabilitating degraded sites because mycorrhiza enables the plants to - [I.A.S. (Pre) 2013]

1. Resist drought and increase absorptive area.

2. Tolerate extremes of pH.

3. Resist disease infestation.

Select the correct answer using the codes given below

(a) Only 1
(b) 2 and 3
(c) 1 and 3
(d) All of these

Correct Answer: (d) All of these

Solution:A mycorrhiza is a symbiotic (generally mutualistic, but occasionally weakly pathogenic) association between a fungus and the roots of a vascular plant. In a mycorrhizal association, the fungus colonizes the host plant’s roots, either intracellularly as in arbuscular mycorrhizal fungi (AMF or AM), or extracellularly as in ectomycorrhizal fungi. They are an important component of soil life and soil chemistry. Mycorrhiza resists drought and increase absorptive area, tolerate extremes of pH and resist disease infestation.

22. ‘Biorock technology’ is talked about in which one of the following situations? [I.A.S. (Pre) 2022]

(a) Restoration of damaged coral reefs
(b) Development of building materials using plant residues
(c) Identification of areas for exploration/extraction of shale gas
(d) Providing salt licks for wild animals in forests/ protected areas

Correct Answer: (a) Restoration of damaged coral reefs

Solution:Biorock technology is an innovative process originally invented in 1976 by the late German-born architect and marine scientist Wolf Hilbertz to produce natural building materials in the sea. It is a unique method that allows coral reefs, and other marine ecosystems including seagrass, salt marsh, mangrove, and other oyster reefs to survive and recover from damage caused by excessive nutrients, climate change, and physical destruction etc. Biorock technology is said to be the only sustainable method of protecting coral reefs from mass extinction from global warming.

23. Phytotron is a facility to- [I.A.S. (Pre) 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:A phytotron is an enclosed research greenhouse used for studying interactions between plants and the environment. Thus, it is a facility to grow plants under controlled conditions.

Phytotrons provide precise control over environmental variables, such as light intensity, photoperiod (day length), temperature, humidity, and CO₂ levels. These facilities are used for a variety of research purposes, including:

Studying plant responses to environmental stresses.
Investigating plant growth and development under different conditions.
Evaluating the effects of various factors, like light, temperature, and humidity, on plant physiology.
Assessing the performance of different plant varieties under specific environmental conditions.
Supporting breeding programs by enabling the testing and evaluation of new plant varieties.

24. Polyhouse is used for- [Uttarakhand P.C.S. (Mains) 2006]

(a) Growing plants
(b) Storing grain
(c) Storing vegetables
(d) None of the above

Correct Answer: (a) Growing plants

Solution:A polytunnel (also known as a polyhouse, hoop greenhouse or hoop house or high tunnel) is a tunnel made of polyethylene, usually semi-circular, square or elongated in shape. These polyhouses are used in agriculture for growing plants. It protects crops from the bright sun, hails, storms etc.

25. Match List-I with List-II [69th B.P.S.C. (Pre) 2023]

List-I (Cloth)	List-II (Origin)
A. Linen	1. Coconut plant
B. Coir	2. Flax plant
C. Mohair	3. Feathers of duck and geese
D. Down	4. Angora goat

Code	A	B	C	D
(a)	1	3	2	4
(b)	4	3	1	2
(c)	2	1	4	3
(d)	4	1	3	2

(a)
(b)
(c)
(d)

Correct Answer: (c)

Solution:The correctly matched lists are as follows:

Cloth	Origin
Linen	Flax plant
Coir	Coconut plant
Mohair	Angora goat
Down	Feathers of duck and geese

26. Angora wool is extracted from: [66th B.P.S.C. (Pre) (Re. Exam) 2020]

Correct Answer: (a) Rabbit

Solution:Angora wool comes from the Angora breed of rabbit, not sheep or goats. It is distinct from "mohair," which comes from the Angora goat. The fibers are very fine, with a halo-like effect, giving items made with Angora a shiny quality. They are also known for their softness, warmth, and luxurious feel. Angora rabbits are bred for their long fibers, and the wool is collected by shearing, combing, or plucking. There have been concerns raised about the welfare of Angora rabbits in some production methods, with some reports of animal cruelty.

27. Angora wool is extracted from which of the following animals? [Jharkhand P.C.S. (Pre) 2023]

(a) Sheep
(b) Goat
(c) Rabbit
(d) Fox

Correct Answer: (c) Rabbit

Solution:Angora wool comes from the Angora breed of rabbit, not sheep or goats. It is distinct from "mohair," which comes from the Angora goat. The fibers are very fine, with a halo-like effect, giving items made with Angora a shiny quality. They are also known for their softness, warmth, and luxurious feel. Angora rabbits are bred for their long fibers, and the wool is collected by shearing, combing, or plucking. There have been concerns raised about the welfare of Angora rabbits in some production methods, with some reports of animal cruelty.

28. Angora wool is obtained from a breed of — [Uttarakhand P.C.S. (Mains) 2002, U.P.P.C.S. (Mains) 2010]

(a) Sheep
(b) Fox
(c) Rabbit
(d) Tibetan Deer

Correct Answer: (c) Rabbit

Solution:Angora wool comes from the Angora breed of rabbit, not sheep or goats. It is distinct from "mohair," which comes from the Angora goat. The fibers are very fine, with a halo-like effect, giving items made with Angora a shiny quality. They are also known for their softness, warmth, and luxurious feel. Angora rabbits are bred for their long fibers, and the wool is collected by shearing, combing, or plucking. There have been concerns raised about the welfare of Angora rabbits in some production methods, with some reports of animal cruelty.

29. Some marine animals and insects emit light from their body in the darkness. This phenomenon is known as: [U.P.P.C.S. (Pre) 2014]

(a) Phosphorescence
(b) Bioluminescence
(c) Both (a) and (b)
(d) None of these

Correct Answer: (b) Bioluminescence

Solution:Bioluminescence is light produced by a chemical reaction within a living organism. The chemical reaction that results in bioluminescence requires two unique chemicals: luciferin and either luciferase or photoprotein. Luciferin is the compound that actually produces light. Most bioluminescent organisms are found in the ocean. These bioluminescent marine species include fish, bacteria, and jellies. Phosphorescence is a process in which energy that is absorbed by a substance is released relatively slowly in the form of light.

30. High-yielding advanced seeds were used in the ‘Green Revolution’, for which the necessary is — [U.P. U.D.A./L.D.A. (Pre) 2001]

(a) Less fertilizer and less water
(b) More fertilizer and less water
(c) Less fertilizer and more water
(d) More fertilizer and more water

Correct Answer: (d) More fertilizer and more water

Solution:The “Green Revolution” is related to the increase in food production of crops on a large scale in developing countries. In the green revolution, to increase productivity, high-yielding advanced seeds were used, for which more fertilizers and more water were necessary.