Organisms normally the least in number in a food chain are Orca whales. The killer whale, also referred to as the orca whale or orca, and less commonly as the blackfish, is a toothed whale belonging to the oceanic dolphin family. 

The timber wolves, rabbits and vegetation in a particular region of Assam together constitute part of a community. A community is all of the living organisms in a particular area at a particular time. A population is all of one species in one area at one time. A species is a group of organisms that look alike and can breed among themselves and a genus is a broader division of classification. 

None of these is a commonly used pesticide.

Ozone is not a major greenhouse gas.  Quantifying the greenhouse gas potency of ozone is difficult because it is not present in uniform concentrations across the globe. However, the most widely accepted scientific assessments relating to climate change suggest that the radiative forcing of troposphere ozone is about 25% that of carbon dioxide.  

All the plants, animals and protists living in a forest make up a community. A community is all of the living or biotic things in one place at one time. A population is just one species in one area at one time. A phylum is a subdivision of a kingdom. 

Ducks and carnivorous fish in a certain pond are secondary consumers. Secondary Consumers are the organisms which depend on the primary consumers for food. Ducks and carnivorous fishes are considered as secondary consumers in a pond ecosystem because they consume zooplankton which is the primary consumer. 

Rate of lung cancer is not affected due to depletion of the stratospheric ozone layer. UVB causes no melanoma skin cancer and plays a major role in malignant melanoma development. In addition, UVB has been linked to cataracts. It is always important to protect your skin and eyes from the sun. Ozone layer depletion increases the amount of UVB and the risk of health effects. 

Hydrocarbons are a non-renewable resource.

Excessive use of pesticides pollutes the lithosphere. Lithosphere is the solid crust from the centre of the earth to the outer surface. It gets polluted due to the dumping of pesticides and herbicides. 

Biodegradable waste material can be made harmless by the action of certain bacteria on them. 

A thin layer of oil on water is called oil slick. Oil slicks float on oceans and seas, covering them with a thick film of crude or refined petroleum oil. When freight ships carrying thousands of tons of fuel crash, malfunction, or encounter harsh weather, they spill enormous amounts of oil into the water. 

CFCs are entirely anthropogenic in origin. CFCs are phased out via the Montreal Protocol due to their part in ozone depletion. However, the atmospheric impacts of CFCs are not limited to its role as an active ozone reducer. This anthropogenic compound is also a greenhouse gas, with a much higher potential to enhance the greenhouse effect than CO₂.  

The feature of organisms to adopt to survive well in a specific environment is called adaptation. The special characteristics that enable plants and animals to be successful in a particular environment are called adaptations.  

Ultraviolet rays are used to clean water in modern filters.

Van Mahotsav is a week-long festival of tree planting that is organised every year in the month of July all across India and lakhs of trees are planted. It is one of the best ways of preventing Earth from global warming. 

The depth at which all the pore spaces are saturated with water only is called water level. The depth at which soil pore spaces or fractures and voids in rock become completely saturated with water is called water level. Groundwater is recharged and eventually flows to the surface naturally. 

One of the best solutions to get rid of non-biodegradable wastes is recycling. Recycling is processing used waste into new products to prevent waste of potentially useful materials, reduce the consumption of fresh raw materials, reduce energy usag, and reduce air pollution and water pollution. One way to prevent the accumulation of non-biodegradable trash is to recycle. 

Global warming has resulted due to increased emissions of CO₂ from automobiles. The main cause of it is greenhouse effect. Naturally occurring amounts of greenhouse gases have a mean warming effect of about 33 °C (59 °F). The major greenhouse gas is carbon dioxide (CO₂) which causes 9-26% of greenhouse effect.

The main cause of mismanagement of natural resources is a large increase in population. As population is increasing day by day, their demand for natural resources is also increasing accordingly which leads to its mismanagement. 

Polar ice caps are expected to be very severely affected by global warming. The immediate effect of it could be coastal and island flooding. The main consequence of global warming is the loss of coastal wetlands and barrier islands, and a greater risk of flooding in coastal communities. Low-lying areas, such as the coastal region along the Gulf of Mexico and estuaries like the Chesapeake Bay, are especially vulnerable. 

Wood is a renewable source of energy. This is because, we can burn recently grown wood, and we can plant more trees. When oil or coal is used up, it's gone and can't be replaced. 

 The use of wood, charcoal, and dung as major sources of energy in developing countries has led to increase in ozone depletion.  Deforestation and the use of fossil fuels are both suspected of increasing the amount of carbon dioxide in the atmosphere. This is of worldwide concern because of its potential effects on the environment, such as global warming due to weakening of the ozone layer which protects the earth from harmful solar radiation.

Hurricanes, Typhoons and Willy-willies will become more common and/or more violent due to global warming. As global warming is the major threat to mankind. All the natural disasters like hurricanes, typhoons etc will become common. 

A habitat characterized by hot and dry places is called xeric. Xeric shrub lands receive an annual average rainfall of ten inches or less, and have an arid or hyper arid climate, characterized by a strong moisture deficit, where annual potential loss of moisture from evapotranspiration well exceeds the moisture received as rainfall.  

CFC causes ozone holes in the ozone layer. The hole in the ozone layer happens because the ozone in the stratosphere is destroyed by chlorine and bromine from halogen atoms. These atoms come from man-made halocarbon refrigerator gases i.e. chlorofluorocarbons or CFCs which are emitted at ground level but move up into the ozone layer.