Q18. What would happen if phytoplankton of an ocean is completely destroyed for some reason? 1. The ocean as a carbon sink would be adversely affected. 2. The food chains in the ocean would be adversely affected. 3. The density of ocean water would drastically decrease. Select the correct answer using the codes given below:

The acidification of oceans is increasing. Why is this phenomenon a cause of concern: 1. The growth and survival of calcareous phytoplankton will be adversely a

Human activities in the recent past have caused the increased concentration of carbon dioxide in the atmosphere, but a lot of it does not remain in the lower at

With reference to food chains in ecosystems, consider the following statements: 1. A food chain illustrates the order in which a chain of organisms feeds upon e

Consider the following kinds of organisms: 1. Copepods 2. Cyanobacteria 3. Diatoms 4. Foraminifera Which of the above are primary producers in the food chains

Consider the following statements : 1. Most of the world's coral reefs are in tropical waters. 2. More than one-third of the world's coral reefs are located in

There is a concern over the increase in harmful algal blooms in the seawaters of India. What could be the causative factors for this phenomenon? 1. Discharge of

Due to some reasons, if there is a huge fall in the population of species of butterflies, what could be its likely consequence/consequences? 1. Pollination of s

In the context of ecosystem productivity, marine upwelling zones are important as they increase marine productivity by bringing the: 1. Decomposer microorganism

There is some concern regarding the nanoparticles of some chemical elements that are used by the industry in the manufacture of various products. Why? 1. They c

With reference to the food chains in ecosystems, which of the following kinds of organism is/are known as decomposer organism/organisms? 1. Virus 2. Fungi 3. Ba

Consider the following factors: 1. Rotation of the Earth 2. Air pressure and wind 3. Density of ocean water 4. Revolution of the Earth Which of the above factor

In the context of mitigating the impending global warming due to anthropogenic emissions of carbon dioxide, which of the following can be potential sites for ca

The scientific view is that the increase in global temperature should not exceed 2°C above the pre-industrial level. If the global temperature increases beyond

What can be the impact of excessive/inappropriate use of nitrogenous fertilizers in agriculture? 1. Proliferation of nitrogen fixing microorganisms in soil can

What is/are the advantage/ advantages of zero tillage in agriculture? 1. Sowing of wheat is possible without burning the residue of the previous crop. 2. Withou

Consider the following statements: The satellite Oceansat-2 launched by India helps in 1. estimating the water vapour content in the atmosphere. 2. predicting t

With reference to agricultural soils, consider the following statements: 1. A high content of organic matter in soil drastically reduces its water holding capa

It is possible to produce algae based biofuels, but what is/are the likely limitation(s) of developing countries in promoting this industry? 1. Production of al

Which of the following are nitrogen-fixing plants? 1. Alfalfa 2. Amaranth 3. Chickpea 4. Clover 5. Purslane (Kulfa) 6. Spinach Select the correct ans

In nature, which of the following is/are most likely to be found surviving on a surface without soil? 1. Fern 2. Lichen 3. Moss 4. Mushroom Select th

Which of the following are detritivores? 1. Earthworms 2. Jellyfish 3. Millipedes 4. Seahorses 5. Woodlice Select the correct answer using the code g

In which one of the following biogeochemical cycles, the weathering of rocks is the main source of release of nutrients to enter the cycle?

Which of the following have species that can establish a symbiotic relationship with other organisms? 1. Cnidarians 2. Fungi 3. Protozoa Select the c

With reference to the water on the planet Earth, consider the following statements: 1. The amount of water in the rivers and lakes is more than the am

Which of the following leaf modifications occur(s) in the desert areas to inhibit water loss? 1. Hard and waxy leaves 2. Tiny leaves 3. Thorns instead

The term ‘M-STrIPES’ is sometimes seen in the news in the context of