Q1. Which one of the following organisms is likely to Which highest concentration of DDT once it has been introduced into the ecosystem? (1996)
(a) Grasshopper
(b) Toad
(c) Snake
(d) Cattle
Ans. (c)
Exp. Among the given organisms, snake is likely to show the highest concentration of DDT once it has been introduced into the ecosystem. DDT is non-biodegradable chemical which cannot be broken down by microbes into simple molecules. Đ²Đµ Due to its non-biodegradable nature, it causes biomagnification. Biomagnification is a phenomenon of increasing the concentration of compound in the tissue of organism as the compound passes up in the food chain during food intake.
Q2. Within biological communities, some species are important in determining the ability of a large number of other species to persist in the community. Such species are called (2000)
(a) Keystone species
(b) Sympatric species
(c) Allopatric species
(d) Threatened species
Ans. (a)
Exp. Within biological communities, some species may be important in determining the ability of large number of other species to persist in the community. These species are called keystone species.
Q3. 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
Ans. (c)
Exp. Phytotron is a facility to grow plants in controlled
conditions.
It is a facility where a number of growth chambers and greenhouses are organized in such a way that different environmental factors can be simulated for research studies simultaneously. It is a chamber. in which plants can be grown in controlled condition. It is used for studying interactions between plants and the environment. Plants are grown under disease free conditions in tissue
Q4. Match List 1 (Indian wildlife species) with List II (scientific names) and select the correct answer using the codes given below. (2002)
| List 1 (Indian wildlife species) | List II (scientific names) |
| A. Asiatic wild ass | 1. Boselaphus tragocamelus |
| B. Barasingha | 2. Cervus duvauceli |
| C. Chinkara | 3. Equus hemionus |
| D Nilgai | 4. Gazella gazella |
Codes
A B C D
(a) 2 3 1 4
(b) 3 2 4 1
(c) 2 3 4 1
(d) 3 2 1 4
Ans. (b) Exp. The correct matching is A-3, B-2, C-4, D-1.
Equus hemionus It is the scientific name of Asiatic wild ass. They are commonly found in varying habitats.com
Cervus duvauceli It is the scientific name of barasingha. It is a type of a deer species which is distributed in the Indian subcontinent.
Gazella gazella It is the scientific name of chinkara, also known as the Indian gazelle.
Boselaphus tragocamelus It is the scientific name of Nilgai and is commonly found in agricultural land.
Q5. Consider the following statements. (2004)
- Toothless mammals such as pangolins are not found in India.
- Gibbon is the only ape found in India.
Which of the statements given above is/are correct?
(a) Only 1
(b) Only 2
(c) Both 1 and 2
(d) Neither 1 nor 2
Ans. (b)
Exp. Only statement (2) is correct, Gibbons (Hylobates) are the apes from the hominid lineage in the evolution of human being. They are found in the rainforests of Assam. Statement (1) in incorrect as Pangolin (Manis) are toothless mammals. They live in tropical Asia and Africa. Common Indian species are Manis crassicaudata (South India). Manis pentadactyla (India to Sri Lanka) and Manis aurita (Nepal to China).
Q6. The release of which one of the following into ponds and wells helps in controlling the mosquitoes? (2008)
(a) Crab
(b) Gambusia fish
(c) Dogfish
(d) Snail
Ans. (b)
Exp. The release of Gambusia fish into ponds and wells helps in controlling the mosquitoes. Gambusia fish, appropriately
named as the ‘mosquito fish’ (Gambusia affinis), is a small, guppy like fish ranging in size from approximately 75 cm to 1.5 inches long. As its name implies, it is a natural predator of mosquito larvae. Gambusia fish is a voracious predator hence used to clean ponds from such larvae.
Q7. Consider the following animals. (2021)
- Hedgehog
- Marmot
- Pangolin
To reduce the chance of being captured by predators, which of the above organisms rolls up/roll up and protects/protect its/their vulnerable parts?
(a) 1 and 2
(b) Only 2
(c) Only 3
(d) 1 and 3
Ans. (d)
Exp. Hedgehog and pangolin are the animal that in order to reduce the chance of being captured by predators rolls up/roll up and protect their vulnerable parts. Hedgehog is a spiny mammal as their body is covered with a coat of stiff and sharp spines. When they are in danger or are attacked by predators they curl into a prickly and unappetizing ball to protect themself. Similarly, Pangolin are also covered with scales. They use these scales to protect themselves from predators. If attacked, Pangolin immediately curl up into a ball and use their sharp scaled tail to defend themselves.
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