1 mark Questions
1. A place where animals are protected in their natural habitat is called a _____________ . Ans: sanctuary. 2. Species found only in a particular area are known as ______. Ans: Endemic species 3. Migratory birds fly to far away places because of ____ _ changes. Ans: Weather /climatic 4. ___________ National Park is the first Reserve Forest of India where the finest Indian teak is found. Ans: Satpura National 5. A group of populations which are capable of interbreeding is called d_______________ Ans: Species 4. Differentiate between the following: (i) Wildlife sanctuary and biosphere reserve Ans: Biosphere Reserve : Large areas of protected land for conservation of wild life, plant and animal resources and traditional life of the tribals living in the area. Wildlife sanctuary: Areas where animals are protected from any disturbance to them and their habitat. (ii) Zoo and wildlife sanctuary Ans: The zoo keeps animals in captivity, within artificially created habitat, whereas the sanctuary provides home to animals in their natural habitat without captivity. (iii) Endangered and extinct species Ans: Animals whose numbers are diminishing to a level that they might face extinction are known as the endangered animal e.g. Tiger where as a species that has completely disappeared from the planet like the pink-headed duck and the cheetah is called extinct species (iv) Flora and fauna Ans: All the different kinds of plants on earth constitute its flora and all its different kinds of animals are collectively called its fauna. 2 marks Questions 1. How does deforestation reduce rainfall on land? Ans: Since plants help in evaporation of water , deforestation reduce rainfall on land. 2. How does deforestation led to floods on the land? Ans: Deforestation also leads to a decrease in the water holding capacity of the soil. The movement of water from the soil surface into the ground (infiltration rate) is reduced. So, there are floods 3. What is the purpose of making national parks, wildlife sanctuaries and biosphere reserves? Ans: The purpose of making national parks, wildlife sanctuaries and biosphere reserves is to conserve and protect the whole ecosystem from exploitation and to protect the ecosystem. 3 mark Questions. 1. Why should we conserve biodiversity? Ans: This is because Biodiversity maintains the environment around us. Plants and animals together maintain several natural cycles such as the oxygen, nitrogen and carbon cycles. These gases in turn play a crucial role in maintaining life on earth. 2. Protected forests are also not completely safe for wild animals. Why? Ans: It is a pity that even protected forests are not safe because people living in the neighborhood encroach upon them and destroy them. 3. Some tribal’s depend on the jungle. How? Ans: Some tribals depend on the jungle as they live in the deep forest like primitive people had lived in ancient time. They are still away from the basic amenities of modern life Forest provide them food items like seed grains, fruit, raw vegetables and other products like honey, meat of hunted wild animals for themselves, fodder for theirs animals, wood fuel for heating and cooking even clothing using natural fibres, leaves and animal skins. 4. What are the causes and consequences of deforestation? Ans: The main causes of deforestation are uses of forest resources by the human being to meet the growing demand of population, rapid urbanization, and industrialization. Some natural causes of deforestation are forest fires and severe droughts. The consequences of deforestation are: (a) Increase in carbon dioxide level in the air. (b) Increase in temperature and pollution level on earth. (c) Lowering in ground water level. (d) More chances of natural calamities like floods and droughts. (e) Soil erosion leading to loss of humus and fertility of the top soil. (f) Desertification of large areas and (g) Decrease in water holding capacity and nutrient content of the soil. 5. What is Red Data Book? Ans: Red Data Book is the source book which keeps a record of all the endangered animals and plants 6. What do you understand by the term migration? Ans: Migration is the phenomenon of movement of a species from its own habitat to some other habitat for a particular time period every year for a specific purpose like breeding. 5 marks Questions 1. In order to meet the ever-increasing demand in factories and for shelter, trees are being continually cut. Is it justified to cut trees for such projects? Discuss and prepare a brief report. Ans: Yes, cutting trees for shelter and supply in factories is proper and justified. But equal number (or more) of trees should be replanted so that the land remains covered with trees and there is least damage to the environment and natural habitat of wild animals. 2. How can you contribute to the maintenance of green wealth of your locality? Make a list of actions to be taken by you. Ans: We can help in maintaining the green wealth of our locality by following ways (a) By planting as many trees as possible in open unused land (b) By reducing use of trees for firewood and other purposes.(c) Recycling and reuse of paper (d) wood should be done to avoid cutting of wood. 3. Why should paper be saved? Prepare a list of ways by which you can save paper. Ans: Paper is made from the pulp of wood. Production of paper on a large scale needs regular supply of trees. This causes deforestation of large areas of land. So, we should save paper. Paper can be saved by: (a) Recycling of used paper. (b) Reusing paper- Note books of previous year having blank pages should be used as rough copies (c) Wastage of paper for fun should be avoided. 4. What will happen if the habitat of an animal is disturbed? Ans: If the natural habitat of animals is disturbed or destroyed, natural balance in the ecosystem will get disturbed and many animals will get extinct. The animals will not be able to live freely in their habitat. 5. Discuss the effects of deforestation on the next generation: Ans: Deforestation increases pollution of air, global warming, reduces rainfall, decrease in ground water level and soil erosion. These problems will be faced by the next generations and will go on increasing. Less rainfall will lead to less food production in the farms. Prices of food items will increase very high. Next generations will also face shortage of fresh water and unfavorable climate change due to deforestation.
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1. Explain the following terms:-
(a) Reproduction- The process of giving rise to new organisms of the same species. (b) Fertilization-The fusion of male & female gametes. (c) Zygote- The single-celled structure formed on the fusion of male & female gametes. (d) Metamorphosis- The gradual transformation of an organism from one form to another during its life cycle (e) Hermaphrodites-The organisms having both male & female reproductive organs in the same body. Eg:- Earthworm, Leech (f) Foetus- The multicellular structure formed after the repeated cell divisions in the Zygote formed as a result of fertilization. (g) Larva- The active form that emerges from the eggs . (h) Placenta- The specialized tissue that attaches the developing foetus to the uterine wall & provides for it nourishment, respiration & excretion. 2. Give reasons for the following:- (a) Gender of the resulting offspring is determined by the male parent in humans. Ans- The Y-chromosome bearing sperm that fertilizes an ovum results in a male offspring. The X-chromosome bearing sperm that fertilizes an ovum results in a female offspring. (b) Sex hormones regulate secondary sexual characters. Ans- The functioning of our reproductive organs is regulated by the sex hormones and one of the functions is the appearance of secondary sexual characters at puberty. (c) Platypus & Echidna lay eggs but are not oviparous animals. Ans- They lay eggs but feed the young ones on milk through the mammary glands. (d) Sperm needs to have motility. Ans – Sperms have to enter the female reproductive passage and fertilize the ovum by travelling through the vagina & uterus for this in the fallopian tube/ oviduct. LONG ANSWER TYPE QUESTIONS:- 1. Explain where the embryo stays till it is fully developed and also explain how its nutritional , respiratory & excretory functions are carried out. Ans- The embryo gets attached to the uterine wall through the Placenta which is a specialized tissue richly supplied by blood & takes care of all the developmental functions of the developing embryo- nutrition, respiration & excretion. 2. What is Asexual reproduction? What are the advantages of this method? Ans- The mode of reproduction that involves a single organisms & also doesn’t require any special organs or cells. Its advantages are:- (a) Offsprings produced are identical to the parents so desired traits can be transmitted to the next generation (b) A quick method of reproduction (c) Only one parent organism is required, no special organs or cells also required. 3. Explain the meaning of Binary Fission. Name a few organisms that reproduce like this & draw a series of diagrams to demonstrate this process in Amoeba. Ans- The method by which an organism divides into two equal halves . Other organisms are:- Paramecium, Euglena, Bacteria. Refer to figure 9.12 of NCERT 4. Explain how budding occurs. Name a few organisms that reproduce like this & draw a series of diagrams to demonstrate this process in Hydra. Ans- Small bulges appear on the sides of the body of the organisms that gradually develop into new organisms. Sponges & Yeast besides Hydra. Refer to figure 9.11 of NCERT 5. What is Metamorphosis? With the help of flow diagrams illustrate the life cycles of a Silkworm & Frog. Ans- Metamorphosis- The gradual transformation of an organism from one form to another during its life cycle. Silkworm:- Egg -->Larva/ Caterpillar--->Pupa/ Cocoon---> Adullt Frog:- Egg---> Tadpole(Larva)- --> Froglet- --> Adult Frog Points to Remember: Plane shapes having two measurements like length and breadth are called two dimensional shapes (2-D).
Solid shapes having three measurements like length, breadth and height or depth are called three dimensional shapes (3-D). In polyhedron relationship between no. of faces (F), vertices (V) and edges (E) is F + V – E = 2 It is also called Euler’s Formula. Prism : A polyhedron whose base and top are congruent polygon and whose other faces are parallelogram. Pyramid : A polyhedron whose base is a polygon and whose lateral faces are triangles with a common vertex. Practice Worksheet 1. Write down the number of faces of each of the following figures: (i) Cuboid (ii) Cube (iii) Triangular prism (iv) Square pyramid (v) Tetrahedron 2. Write down the number of edges of each of the following figures: (i) Tetrahedron (ii) Rectangular pyramid (iii) Cube (iv) Triangular prism 3. Write down the number of vertices of each of the following figures: (i) Cuboid (ii) Square pyramid (iii) Tetrahedron (iv) Triangular prism 4. Fill in the blanks: (i) A cube has …………….. vertices, …………….. edges and …………….. faces. (ii) The point at which three faces of a figure meet is known as its …………….. . (iii) A cuboid is also known as a rectangular …………….. . (iv) A triangular pyramid is called a …………….. . Answers: 1. (i) 6 (ii) 6 (iii) 5 (iv) 5 (v) 4 2. (i) 6 (ii) 8 (iii) 12 (iv) 9 3. (i) 8 (ii) 5 (iii) 4 (iv) 6 4. (i) 8, 12, 6 (ii) vertex (iii) prism (iv) tetrahedron Q. Name each of the following parallelograms.
(i) The diagonals are equal and the adjacent sides are unequal. (ii) The diagonals are equal and the adjacent sides are equal. (iii) The diagonals are unequal and the adjacent sides are equal. (iv) All the sides are equal and one angle is 60°. (v) All the sides are equal and one angle is 90°. (vi) All the angles are equal and the adjacent sides are unequal. Ans: (i) rectangle (ii) square (iii) rhombus (iv) rhombus (v) square (vi) rectangle Q. State whether True or False. a) All rectangles are squares Answer: All squares are rectangles but all rectangles can’t be squares, so this statement is false. (b) All kites are rhombuses. Answer: All rhombuses are kites but all kites can’t be rhombus (c) All rhombuses are parallelograms Answer: True (d) All rhombuses are kites. Answer: True (e) All squares are rhombuses and also rectangles Answer: True; squares fulfill all criteria of being a rectangle because all angles are right angle and opposite sides are equal. Similarly, they fulfill all criteria of a rhombus, as all sides are equal and their diagonals bisect each other. (f) All parallelograms are trapeziums. Answer: False; All trapeziums are parallelograms, but all parallelograms can’t be trapezoid. (g) All squares are not parallelograms. Answer: False; all squares are parallelograms (h) All squares are trapeziums. Answer: True For pdf Files Download 8th MCQ Parallelograms and quadrilaterals 8th Parallelogram solved Extra Edugain Questions VIII Unsolved Extra Edugain Questions 8th Quadrilateral and Parallelogram Guess Questions Download File |
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