Select the correct answer from the 4 option given. Questions are explained with correct answer and explanation.
Q. Which of the statement is not true for the term “species”?
Ans. Species are defined as a group of individuals and similar interbreeding population that are capable of exchanging genes. Thus, gene occurs between the populations of a species.
Q. What is the study of relationship and interaction of organisms with their environment is known as
Ans. Ecology is the branch of science that studies the interaction of organisms and their environment. Also known as environmental biology, bionomics, and bio ecology that deals with the study of inter-relationship of organisms with their surroundings.
Q. Which of the following statement is true of ecosystem?
Ans. Ecosystem is a biological community of organisms where they interact with their physical environment by the mean of natural chemical cycles, food chains etc. It is a community of living and non-living organisms where they are depended on each other. An ecosystem comprises of producers, consumers, and decomposers. In an ideal ecosystem, the number of producers is always greater than the number of consumers.
Q. Deforestation result in reduced
Ans. Deforestation reduces rainfall. Deforestation is basically cutting of forests that results in destruction of biodiversity and natural habitat. The air passing over the forests picks the moisture from trees, soil and natural vegetation of the forest and helps in rainfall. The cutting of trees disturbs the natural cycle of collecting moisture that increase the temperature and this ultimately leads to reduction in the rainfall.
Q. The reason behind the productivity of black soil is the
Ans. Black soil is rich in clay and humus and this makes the soil more productive. Humus is the organic component that comes from the dead and decayed animals and plants and is decomposed by the microorganisms present in soil. The rich nutrients present in the humus makes the black soil more fertile and productive.
Q. What is petroleum?
Ans. Petroleum is a fossil fuel that comes from the earth and all the fossil fuels are non-renewable source of energy. It is present in a limited amount on earth and will be replenished in coming future. It is a non-renewable resource as it cannot be re-grown and recycled. It takes millions of year to form and cannot be renewed.
Q. Which of the following is the reason for Acid rain?
Ans. Acid rain is another form of precipitation that is acidic in nature and has pH less than 5. It is caused by the burning of fossil fuels like coal, petrol etc. The combustion of these fossil fuels releases harmful oxides of sulfur and nitrogen in the air and form acid rain.
Q. Which of the following is a renewable source of energy?
Ans. Biomass is one of the best example of renewable sources of energy. Biomass comprises of organic material that comes from plants and animals and have stored energy from sun. Biomass is a fuel that helps in production of energy from wood, agricultural waste, garbage, dead plants & trees, municipal solid waste, animal waste, and other organic waste without emitting any harmful gases in the environment. Biomass is renewable, sustainable & clean source of energy as it purely comes from organic material.
Q. What would be the temperature of earth’s surface if there will be no CO2 in the earth’s atmosphere?
Ans. The answer is the temperature of earth’s surface will be less than the present temperature. It is because CO2 is one of the greenhouse gases that absorbs the sunrays and keeps the earth warms. Higher the amount of CO2 in the atmosphere higher will be the temperature and vice-versa.
Q. Choose the correct food chain
Ans. The phytoplankton are at the first stage in the aquatic food chain. Every food chain comprises of series of organisms that are depended on other organisms for food. Here, option (a) shows the correct order of the food chain where phytoplankton is the producer, zooplankton is the primary consumer and fish is the secondary consumer.
The main factor of desertification is
Ans. The process of turning of arable and fertile land into a desert is known as desertification. Drought, overgrazing, deforestation, over-cultivation, bad agriculture practices, pollution, and other human activities are some of the reasons behind desertification.
Q. The reaction caused from the ultraviolet rays of the sun produces
Ans. Ozone is produced when sunrays fall on earth and makes the oxygen molecule split into two single atoms. These atoms then combine with the nearby oxygen and form three oxygen molecules known as Ozone (O3). The ozone layer protects the earth from the harmful ultraviolet radiations of the sun.
Q. The group/population of same kind of organisms living together is called as
Ans. The species is group of same kind of living organisms capable of interbreeding and of exchanging genes.
Q. Which of the following are known as “nature’s scavengers”?
Ans. Microorganisms are called as “nature’s scavengers”. It is because they feed on dead and decaying animals & plants and decompose them into small compounds. By doing so, they also help in cleaning the environment.
Q. The reason behind the warming of earth’s greenhouse is
Ans. Greenhouse effect is the process of warming of earth’s surface/ atmosphere by absorbing the radiations from sun. Greenhouses gases such as CO2, water vapors, methane etc. absorbs the radiations from the sun and causes greenhouse effect. The increase in the concentration of Carbon dioxide and other greenhouse gases in the atmosphere absorb more radiation and increase the temperature of the greenhouse and ultimately leads to global warming.
Q. Metals and minerals are
Ans. Minerals and metals comes under the category of by renewable and non-renewable resources. Minerals and metals both are natural resources and most of them cannot be recycled making them the non-renewable resources. However, there are minerals and metals (biogenetic nutrients) that can be recycled easily and making them a hybrid between the classification of renewable and non-renewable resources.
Q. Among the following the most hazardous automobile exhausts metal pollutant is
Ans. Lead is one of the hazardous metal pollutant that has adverse effects on human health. It affects the nervous system, causes lead poisoning, kidney diseases, anemia, convulsion etc.
Q. What does MAB stands for
Ans. MAB stands for Man and the Biosphere Program. It is an intergovernmental scientific program of UNESCO launched in 1971. The objective of this program revolves around the sustainable development, improvement of environment conservation strategies, and various other issues related to the protection of biodiversity and environment.
Q. Which of the following is a non-renewable resource?
Ans. The conventional energy sources basically refers to the natural resources which are limited and are in common use since a long time such as coal, petroleum, natural gas etc. These conventional sources are also known as non-renewable source of energy as they come from sources that will be replenished in the coming future. Such natural resources cannot be reproduced, reused and will eventually run out.
Q. How does the fertility of soil is measured?
Ans. The fertile nature of soil supports the abundant plant life. More fertile the soil will be more will be the growth of plants in it and hence life. The fertility of soil can be measured by its ability to sustain the growth of agricultural plants.