ECOSYSTEM (Part-II)

Total Questions: 40

31. Plants grown at which of the following places take up carbon dioxide during the night? [S.S.C. Online Graduate Level (T-1) 18.08.2021 (Shift-I)]

(a) Ocean beds
(b) Hilly terrains
(c) Deserts
(d) Roof tops

Correct Answer: (c) Deserts

Solution:Deserts.
Plants in deserts often exhibit Crassulacean Acid Metabolism (CAM) photosynthesis. This adaptation allows them to open their stomata and take in carbon dioxide during the cooler night hours to minimize water loss through transpiration during the hot, dry day. The CO2 is stored and then used for photosynthesis during the day when sunlight is available.

32. The water which is suitable for drinking is called? [S.S.C. Online MTS (T-1) 4.10.2017 (Shift-I)]

(a) Potable water
(b) Portable water
(c) Pure water
(d) Sterile water

Correct Answer: (a) Potable water

Solution:

Potable water.

Potable water: Water that is safe to drink or to use for food preparation.

Portable water: Water that can be easily carried.

Pure water: Chemically $H₂ O$ , which is often demineralized and not necessarily suitable for long-term drinking.

Sterile water: Water that is free from all living microorganisms, often used in medical or laboratory settings, but not necessarily suitable for drinking (e.g., due to lack of minerals).

33. Which cycle shows the movement of water? [S.S.C. Online CHSL (T-1) 02.06.2022 (Shift-II)]

(a) Nitrogen cycle
(b) Hydrological cycle
(c) Carbon cycle
(d) Geological cycle

Correct Answer: (b) Hydrological cycle

Solution:Hydrological cycle.
The hydrological cycle, also known as the water cycle, describes the continuous movement of water on, above, and below the surface of the Earth.

34. The resources obtained from the biosphere, such as humans, flora, fauna, fish, livestock, etc., which contain life, are called what? [SSC Online Constable GD 12.02.2019 (Shift-II)]

(a) Bio-resources
(b) Potential Resources
(c) Abiotic resources
(d) Renewable Resources

Correct Answer: (a) Bio-resources

Solution: Bio-resources.
Bio-resources are resources that are living or derived from living organisms, including plants, animals, and microorganisms. They are obtained from the biosphere.

35. Which of the following is not a function of forests? [S.S.C. Online MTS (T-I) 19.09.2017 (Shift-III)]

(a) Providing oxygen
(b) Conservation of soil and providing habitat to a large number of animals
(c) Helping bring good rainfall to the surrounding area
(d) Do not tamper with the water cycle and air quality

Correct Answer: (d) Do not tamper with the water cycle and air quality

Solution:Do not tamper with the water cycle and air quality.
Forests play a crucial role in maintaining the water cycle (through evapotranspiration and promoting rainfall) and improving air quality (by absorbing pollutants and producing oxygen). The phrase "Do not tamper with" implies they have a neutral or negative effect, which is incorrect. Forests actively regulate and improve the water cycle and air quality.

36. Which one of the following is called a "Dynamic Living Unit"? [S.S.C. Online MTS (T-I) 18.09.2017 (Shift-III)]

(a) Soil
(b) Water
(c) Forest
(d) Air

Correct Answer: (c) Forest

Solution:Forest.
A forest is a complex ecosystem that is constantly changing and evolving due to the interactions between its living (biotic) components (trees, animals, microorganisms) and non-living (abiotic) components (soil, water, sunlight). This constant interaction and change make it a "Dynamic Living Unit."

37. ______ is a byproduct of sewage treatment and can be decomposed to produce biogas. [S.S.C. Online Graduate Level (T-I) 6.09.2016 (Shift-III)]

(a) Sewage
(b) Sludge
(c) Sewer
(d) Scum

Correct Answer: (b) Sludge

Solution: Sludge.
During sewage treatment, solid waste settles at the bottom of tanks, forming sludge. This sludge is rich in organic matter and can be anaerobically digested to produce biogas (primarily methane), which is a renewable energy source.

38. Solids like fats, grease, and oil that float on top of liquid wastewater are called ______. [S.S.C. Online CGL (T-1) 21.04.2022 (Shift-I)]

(a) Urea
(b) Sludge
(c) Compost
(d) Peat

Correct Answer: (b) Sludge

Solution:Scum.
Fats, oils, and grease (FOG) are lighter than water and tend to float on the surface of wastewater, forming a layer known as scum. Sludge, conversely, refers to the heavier solids that settle at the bottom.

39. What are the dissolved and suspended impurities in sewage called? [S.S.C. Online MTS (T-1) 21.09.2017 (Shift-I)]

(a) Adulterant
(b) Waste
(c) body
(d) contaminant

Correct Answer: (d) contaminant

Solution:Contaminant.
Dissolved and suspended impurities in sewage are generally referred to as contaminants or pollutants because they degrade the quality of the water and can be harmful.

40. Which of the following is NOT a storage root? [S.S.C. Online Graduate Level (T-I) 18.06.2021 (Shift-I)]

(a) Napiform root
(b) Conical root
(c) Breathing root
(d) Fusiform root

Correct Answer: (c) Breathing root