Friday, April 19, 2013

Formative Assessment - CBSE Class 7th Nutrition in plants and animals

 CBSE Class 7th Nutrition in plants and animals : Formative Assessment 

Q. What is food?

Answer: Food is fuel for living things.

Q.  Why we need to eat food?

Answer: Food is a basic need for all living things to live fit and active. It is because food provides energy to all living body to do their life activities. Food also helps to grow and build their bodies.

Q. What are nutrients?

Answer: Chemicals present in food that nourish body are called nutrients. They are Carbohydrates, Fats, protein, Vitamin, minerals, Water and roughage.

Q. What is nutrition?

Answer: The process of taking and utilization of food by the body is called nutrition.

Q. What are the different modes of nutrition?

Answer: Autotrophic, Heterotrophic, parasitic and Saprophytic nutrition.

Q. What are Autotrophic and Heterotrophic nutrition?

Answer: The mode of nutrition by which green plants utilize their own prepared food is called autotrophic nutrition.

The mode of nutrition by which non green plants and animals utilize food is called Heterotrophic nutrition.

Q. What is the name given to green substance present in leaves of plants?

Answer: Chlorophyll.

Q. What is the name given to small pores present in leaves?

Answer: Stomata through which air comes into the leaf.

Q. What is photosynthesis?

Answer: The process by which green plant prepare food using sunlight, CO2, Water mineral and nitrates is called  photosynthesis.

           6CO2 + 6H2 --->  C6H12O6   + 6O2

Q. Why is the sun called the ultimate source of energy for all forms of life?

Answer: Most living organism get the food prepared by plant using sunlight. In the absence of food, life would be impossible on earth. So, the sun is the ultimate source of energy for all forms of life.

Q. What are Saprophytes? How do they get their nutrients?

Answer: Non green plants that feed on dead and decay matter to get their nutrients is called Saprophytes and their mode of nutrition is called saprophytic nutrition. e. g. Mushroom, Bread mould.

Q. What are Insectivorous Plants? How do they get their nutrients?

Answer: Green plants that feed on insect to fulfill need of nitrogen are called Insectivorous Plants. For example venues fly trap and pitcher plant.

Q. Name a plant that has both autotrophic as well as heterotrophic mode of nutrition?

Answer: Pitcher plant

Q. Name the bacterium that converts atmospheric nitrogen into a soluble nitrate?

Answer: Rizobium.

Q. If the pitcher plant is green and carries out photosynthesis then why does it feed on insects?

Answer: Insectivorous Plants need to eat insects because their soil does not have certain nutrients like nitrogen for them to grow.

Q. What is symbiotic relationship?

Answer:   When two different types of organisms live together and mutually help each other for nutrition. They are said to live in symbiotic relationship.

Q. How fungus and alga fulfill their nourishment?

Answer: The algae are green enough to prepare food but cannot absorb water and minerals. So algae supply food and shelter to fungi and fungi absorb water and minerals.

Q. Name the organisms that consist of a fungus and alga.

Answer: Lichens

Q. How can you justify that humans and animals are directly or indirectly dependent on plants?

Answer: Plants can prepare their food themselves but animals including humans cannot. They get it from plants or animals that eat plants. Thus, humans and animals are directly or indirectly dependent on plants.

Q. why our body cannot make food from carbon dioxide, water and minerals like plants do?

Answer: It is so because we do not have chloroplasts that contain the green pigment called chlorophyll.

Q. Why are leaves called the food factories of plants?

Answer: This is because the synthesis of food in plants occurs in leaves.

Q. Why all living organisms require food?

Answer: All living organisms require food to keep healthy and fit and active.

Q. What is the stored form of carbohydrates in plants?

Answer: Starch

Q. .Why in the rainy season does a loaf of bread turn blue, brown or greenish?

Answer: Due to growth of fungi

Q. Proteins are nitrogenous substances which contain nitrogen. (T/F)

Answer: True

Q. How are nutrients replenished in the soil?

Answer: Nutrients are replenished in the soil by growing leguminous plant which shelter Rizobium bacteria that convert atmospheric nitrogen into nitrate and make soil fertile.

Q. Why Cuscuta is called total parasite?

Answer: Cuscuta is called total parasite as it fully depends on green plants for food. It sucks food through haustoria (parasitic roots).

Q. Why mistletoe is called partial parasite?

Answer: Mistletoe is called partial parasite as it depends on host plant only to get mineral and water but prepare own food.

Q. Name the components of food other than carbohydrates synthesized by Plants?

Answer: proteins and fats by using nitrogen.

Q. How water and minerals absorbed by roots reach the leaves.

Answer: In plants water and minerals absorbed by roots hair and reach to leaves through transporting tissue xylem.

Q. What is osmosis?

Answer: The movement of water from high concentration to low concentration through semi permeable membrane is called osmosis.

Q. What is ascent of sap?

Answer: The force by which water forced upward to ward leaves is called ascent of sap.

Q. Leaves of certain variety of cabbage are purple in colour. Are they able to do photosynthesis? Give a suitable reason?

Answer: This is because the large amount of red, brown and other pigments color contain the green colour

Q. Why do we get instant energy from glucose?

Answer: This is because Glucose is the simplest carbohydrate which is instantly absorbed in the blood stream and supplies energy.

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