CBSE Class 7 Science Nutrition in Plants Assignment

QI Answer : the following questions-

1 Name the process by which green plants make their food.
Answer : Photosynthesis

2 What type of heterotroph is a frog?
Answer : Carnivore

3 What is the mode of nutrition in fungi?
Answer : Saprophytic

4 Where does the bacterium Rhizobium live?
Answer : In the root nodules in a legume

5 Which type of nutrition is shown by non green plants?
Answer : Heterotrophic

6 Name one plant showing the saprophytic mode of nutrition.
Answer : Fungi

7 Name the two components in the thallus of Lichens.
Answer : Alga and fungus

8 What type of heterotroph is a deer?
Answer : Herbivores

9 Name any 2 factors affecting the rate of photosynthesis?
Answer : Light intensity,Co2 and water

10 What type of heterotroph is a crow?
Answer : Omnivore

Q II Tick the odd –one out giving reason-

1 Green plants, Photosynthesis, Producer, Carnivores, Carbon di oxide.
Answer : Carnivore because it is a heterotroph and not related to the process of photosynthesis.

2 Starch, Iodine solution, Stomata, Saprophyte.
Answer : Saprophyte because it is not related to starch test.

3 Water, Chlorophyll, Root hair, Carbon di oxide.
Answer : Root hair because it is associated with absorption of water from soil.

4 Fungi, Mushroom, Saprophytes, Cuscuta.
Answer : Cuscuta because it is totally parasitic plant.

5 Manure, Urea, Ammonium nitrate, Rhizobium.
Answer : Rhizobium because it is a natural biological nitrogen fixture.

Nutrition in Plants

Q.1 Match the following :-
 

Answer: a - ii, b - iii, c - iv, d - i, e - v, f - vi
In simple words: Match each organism or plant type with its correct mode of nutrition.

Exam Tip: Memorize the specific categories of plant nutrition like autotrophic, parasitic, saprotrophic, and insectivorous.

Q.2 Neatly label the following diagram. Diagram showing photosynthesis
Answer:
- Sun / Sunlight
- Carbon dioxide (absorbed from air)
- Oxygen (released during photosynthesis)
- Chlorophyll (in leaves)
- Water and minerals (absorbed by roots from soil)
- Carbohydrates (food produced in leaves)
In simple words: The diagram illustrates the inputs (sunlight, carbon dioxide, water) and outputs (oxygen, carbohydrates) of photosynthesis.

Exam Tip: Always show arrows clearly showing gas exchange and water uptake in photosynthesis diagrams.

Q.3 Label the following diagram of stomata.
Answer:
- Guard cells
- Stomatal pore / Stoma
- Chloroplast
- Nucleus
- Epidermal cells
In simple words: Stomata are tiny pores on leaves surrounded by guard cells that help in gas exchange.

Exam Tip: Practice drawing guard cells as kidney-shaped structures with thickened inner walls.

Q.4 Fill in the blanks
Answer:
- Leguminous Plants i.e. Peas
- Rhizobium bacteria
- Symbiotic relationship
In simple words: Rhizobium bacteria live in the roots of leguminous plants and share a symbiotic relationship where both organisms benefit.

Exam Tip: Rhizobium fixes atmospheric nitrogen into soluble nitrates for plants.

Q.5 Complete the following equation representing photosynthesis.
\(\text{CO}_2 + \text{H}_2\text{O} \xrightarrow[\text{Chlorophyll}]{\text{Sunlight}} \text{Carbohydrate} + \text{Oxygen}\)
Answer:
Carbon dioxide (\(\text{CO}_2\)) + Water (\(\text{H}_2\text{O}\)) \(\xrightarrow[\text{Chlorophyll}]{\text{Sunlight}}\) Carbohydrate + Oxygen
In simple words: Plants use sunlight and chlorophyll to convert carbon dioxide and water into food (carbohydrate) and oxygen.

Exam Tip: Always write Sunlight above the arrow and Chlorophyll below the arrow in the photosynthesis equation.