Read and download free pdf of CBSE Class 10 Biology Our Environment Management Of Natural Resources Worksheet Set A. Students and teachers of Class 10 Biology can get free printable Worksheets for Class 10 Biology in PDF format prepared as per the latest syllabus and examination pattern in your schools. Standard 10 students should practice questions and answers given here for Biology in Grade 10 which will help them to improve your knowledge of all important chapters and its topics. Students should also download free pdf of Class 10 Biology Worksheets prepared by school teachers as per the latest NCERT, CBSE, KVS books and syllabus issued this academic year and solve important problems provided here with solutions on daily basis to get more score in school exams and tests
SUBJECT - BIOLOGY CLASS- X
ASSIGHNMENT NO 7
Question. How can we help in reducing the problem of waste disposal? Suggest any three methods.
Ans. Methods to reduce the problem of waste disposal:
(1) Segregation of waste should be done by separating biodegradable waste substances from non-biodegradable substances.
(2) By recycling solid wastes like paper, plastic and metals etc, i.e., they are reprocessed or melted and remoulded to make new articles.
(3) By composting biodegradable domestic wastes such as fruit and vegetable peels, leaves of potted plants can be converted into compost and used as a manure.
(4) By reducing and reusing of Non Biodegradable substances.
Question. Explain some harmful effects of agricultural practices on the environment.
Ans. Harmful effects of agricultural practices on the environment:
(1) Fertilizer added to soil not only changes the chemistry of the soil but also kills many useful microbes.
(2) Pesticides sprayed over crops reach water bodies and persistent pesticides undergo bio-magnification proving harmful to higher organisms.
(3) Extensive cropping on a particular piece of land causes the loss of soil fertility.
(4) Continuous use of ground water in agriculture has resulted in lowering of water table at most of the places
(5) Natural ecosystems and habitats have been damaged because of clearing of land for agriculture.
(6) Excessive cutting down of trees for agricultural purposes causes deforestation and can lead to soil erosion.
(7) Synthetic fertilizers and pesticides used in the field during rainfall are washed away to rivers and other bodies, which cause water pollution.
Question. (A) Construct a terrestrial food chain comprising four trophic levels.
(B) What will happen if we kill all the organisms in one trophic level?
(C) Calculate the amount of energy available to the organisms at the fourth trophic level if the energy available to the organisms at the second trophic level is 2000 J.
Ans. (A) A terrestrial food chain comprising of fourt trophic levels: Grass → Grasshopper → Frog → Snake
(B) If we kill all the organisms in one trophic level the transfer of food energy to next level will stop. Organisms of previous trophic level will also increase. For example: If all herbivores in an ecosystem are killed: There will be no food available for the carnivores of that area. Consequently they will also die or will shift to other areas. Populations of producers will also increase in absence of herbivores causing imbalance in the ecosystem.
(C) Consider the same food chain as we have made in 1% (a): Grass → Grass hopper → Frog → Snake In this food chain, second trophic level is grass hopper and the energy available at this trophic level is 2000 j. According to 10% law, 10% of energy will be available to frog (Third trophic level) which is 200 j. The energy available to the snakes will be available as 10% of 200 j. Thus, the energy available to the snake is 20 %. Explanation: 10% law states that during transfer of energy from one trophic level to the next trophic level, only about 10% energy is available to the higher trophic level. To summarise: Grass → Grass hopp
Question. What are the advantages of cloth bags over plastic bags during shopping?
Ans. Advantages of cloth bags over plastic bags during shopping are as follows:
(1) Cloth bags are more durable and thus can be used again and again.
(2) They are strong and thus capable of carrying more things.
(3) They are biodegradable in nature.
TOPIC- Our environment Management of natural resources
MCQ’S Based on practical skills
1) A small protuberance observed in yeast cells is called the
a) Flagella b) Pseudopodia c) Branch d)Bud
2) Which part of amoeba cell first undergoes a change during binary fission?
a) Nucleus b) Cytoplasm c) Pseudopodia d)Vacuole
3) In raisins water enters by the process of
a) exosmosis b) endosmosis c) diffusion d) plasmolysis
4) What is the sign of asexual reproduction taking place in yeast cells?
a) vigorously shaking yeast cells b) a chain of buds on yeast cells
c) many single yeast cells d) very large size of yeast cells
5) During one binary fission
a) two parent cells produce one daughter cell
b) two parent cells produce two daughter cells
c) one parent cell produces one daughter cell
d) one parent cell produces two daughter cells
6) Which of the following statements isa correct?
a) Binary fission is a type of sexual reproduction
b) Budding is a type of asexual reproduction
c) both binary fission and budding is a type of sexual reproduction
d) Budding is a type of asexual reproduction and binary fission is a type of sexual reproduction
7) A hypertonic solution has
a) higher water concentration than the cell sap
b) lower concentration than the cell sap
c) lower water concentration than the cell sap
d) higher concentration than the cell sap
8) While performing an experiment with raisins, a student recorded the following data Mass of water taken in the beaker- 50g, Mass of raisins before soaking- 20g, Mass of raisins after soaking- 30g, Mass of water left in the beaker after experiment. The % of water absorbed by the raisins is
a) 10% b) 20% c) 45% d) 50%
More Important Questions For Our Environment
Question. Food web increases the stability of an ecosystem. Justify.
Ans. Food web shows feeding connection in an ecological community. It consists if many food chains. Thus, if any one organism becomes endangered or extinct, the one dependent in it has an alternative option available to him for its survival. In this way food web increases stability in the ecosystem.
Question. Pesticides like DDT which are sprayed to kill pests on crops to kill pests on crops are found to be present in the soil, groundwater, water bodies etc. Explain. How do they reach these places?
Ans. Soil: Pesticides are used to protect plants from insects. They consequently get settled into soil particles, when used on plants.
Groundwater: Through irrigation in the fields, these pesticides present in soil pass into lower layers of soil and reach groundwater.
Water bodies: When the wastewater or other agricultural waste is thrown in water bodies like river, canals, ponds, etc. the pesticides affect water bodies.
Question. Organisms which synthesise carbohydrates from inorganic compounds using radiant energy are called:
Ans. (b) Producers
Question. Write any two consequences if decomposers are removed from the ecosystem?
Ans. (i) Dead organisms will pile up.
(ii) There will be no replenishment of soil.
Question. An ecosystem includes:
(a) All living organisms
(b) Non-Living objects
(c) Both Living and Non-living objects
(d) sometimes living and sometimes non-living
Ans. (c) Both Living and Non-living objects
Question. The first tropic level in a food chain is always a green plant. Why?
Ans. Because only plants can utilise the radiant energy of the sun and transform it to chemical form during photosynthesis.
Question. (a) “Energy flow in a chain is unidirectional”. Justify this statement. Explain how the pesticides enter a food chain and subsequently get into our body.
(b) What is an ecosystem? List two main components.
Ans. (a) Because the energy moves progressively through the various trophic levels and is no longer available to the previous trophic level. The energy captured by autotrophs does not revert back to the solar input.
* Pesticides, used for crop protection when washed down into the soil/water body, are absorbed by the plant along with water and minerals
* Being non-biodegradable, these chemicals get accumulated progressively in the food chain and into our body
(b)A self-sustaining functional unit consisting of living and non-living component is called an ecosystem.
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