Answer: Option C. -> Increasing population
Answer: (c)
Deforestation is a consequence of a quantum jump in population and the consequent over-exploitation of our natural ecosystems for space, energy and materials. Expanding agriculture due to a burgeoning population base is one of the most important causes of deforestation.
As demands on agricultural products rise more and more land is brought under cultivation for which forests are cleared, grass-lands ploughed, uneven grounds levelled, marshes drained and even land underwater is reclaimed.

Answer: Option C. -> deciduous
Answer: (c)
Deciduous means “falling off at maturity” “ or “tending to fall off”. It is typically used in order to refer to trees or shrubs that lose their leaves seasonally most commonly during autumn and to the shedding of other plant structures such as petals after flowering or fruit when ripe.
Common examples of deciduous trees include oak, maple, and hickory trees.

Answer: Option C. -> Decrease in the number of rats
Answer: (c)There will be a decrease in the number of rats simply because rat is a prey to all the three of them and this leads to just a single conclusion that there is decrease in the number of rats.

Answer: Option C. -> a living community and its environment.
Answer: (c)An ecosystem consists of communities of many different species living together, and all the the physical aspects of the particular habitat, such as like soil, water, and weather.

Answer: Option D. -> Grasslands
Answer: (d)The Steppe is a dry, cold, grassland that is found in all of the continents except Australia and Antarctica. It is mostly found in the USA, Mongolia, Siberia, Tibet and China. is usually found between the desert and the forest.

Answer: Option C. -> Carbon-di-Oxide
Answer: (c)A greenhouse gas (sometimes abbreviated GHG) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapour, carbon dioxide, methane, nitrous oxide, and ozone.

Answer: Option B. -> Biosphere
Answer: (b)Part of the Earth’s surface and atmosphere that contains the entire terrestrial ecosystem, and extends from ocean depths to about six kilometers above sea level. Not precisely demarkable, it contains all living organisms and what supports them soil, subsurface water, bodies of water, air and includes hydrosphere and lithosphere.

Answer: Option A. -> Forests
Answer: (a)Forest is a renewable resource.

Answer: Option D. -> Tropical rain forests
Answer: (d)
Most of the terrestrial diversity is found in tropical rainforests. As per an estimation, these forests account for around 40% to 75% of all biotic species and are home to half of all the living animal and plant species on the planet.
A single hectare of rainforest may contain 42,000 different species of insect, up to 807 trees of 313 species and 1,500 species of higher plants.

Answer: Option A. -> Equatorial regions
Answer: (a)
The rubber plant grows wild in the equatorial regions of the world which are marked by rainfall of around 250 cm evenly distributed without any marked dry season and with at least 100 rainy days per year; temperature range of about 20°C to 34°C with a monthly mean of 25°C to 28°C; and high atmospheric humidity of around 80%.
The three largest producing countries, Thailand, Indonesia and Malaysia, together account for around 72% of all-natural rubber production.