CBSE Class 7th Nutrition in plants and animals :
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.
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
Answer: This is because Glucose is the simplest carbohydrate which
is instantly absorbed in the blood stream and supplies energy.
For more click links given below:
Obtaining and Utilization Food Class 7 Science Solved question (Basic Science Questions answers)
For more click links given below:
Obtaining and Utilization Food Class 7 Science Solved question (Basic Science Questions answers)
Comments
Post a Comment