Science worksheet focusing on plant nutrition, including topics like photosynthesis, nutrient absorption, and plant structures.

Worksheet 1: Nutrition in Plants

#### 1. Fill in the blanks.

(a) Nutrition of living organisms is classified into ________ categories.
- Answer: Two (Autotrophic and Heterotrophic)

(b) Water and nutrients absorbed by the roots of the plant reach to the leaves through ________.
- Answer: Xylem

(c) ________ is a bacterium that lives in the root nodules of leguminous plants.
- Answer: Rhizobium

(d) ________ is needed by the body for growth, energy to carry out various activities.
- Answer: Nutrients (or Food)

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#### 2. Match the following.

| Column A | Column B |
|-------------------|------------------------------------|
| (a) Pitcher plant | (iii) Leaves modified to form a pitcher-like structure with a lid |
| (b) Rhizobium | (iv) Converts atmospheric nitrogen into nitrogenous compounds |
| (c) Chloroplast | (ii) Green pigment in the plant's leaf |
| (d) Venus flytrap | (i) Two flap-like structures of leaves having stiff, sticky hairs |

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#### 3. Give two examples of each of the following.

(a) Parasitic plants
- Examples: Cuscuta (Dodder), Orobanche (Broomrape)

(b) Saprophytic plants
- Examples: Monotropa uniflora (Indian Pipe), Neottia nidus-avis (Bird’s-nest orchid)

(c) Symbiotic plants
- Examples: Legumes (e.g., Pea, Bean) with Rhizobium bacteria, Lichens (fungus + algae)

(d) Fungi
- Examples: Penicillium (used in antibiotics), Aspergillus (common mold)

(e) Partial parasite
- Examples: Mistletoe (Viscum album), Dodder (Cuscuta)

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#### 4. Answer the following questions.

(a) Define nutrition.
- Answer: Nutrition is the process by which an organism obtains and utilizes food substances to sustain life, growth, and development. It involves the intake, digestion, absorption, assimilation, and utilization of nutrients.

(b) Define photosynthesis.
- Answer: Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy (usually from the sun) into chemical energy stored in glucose. This process occurs in the chloroplasts and requires carbon dioxide, water, and sunlight. The overall equation is:
\[
6CO_2 + 6H_2O + \text{Light Energy} \rightarrow C_6H_{12}O_6 + 6O_2
\]

(c) What is the role of guard cells in a plant’s leaves?
- Answer: Guard cells are specialized cells surrounding the stomata (tiny pores) on the surface of leaves. Their primary role is to regulate the opening and closing of stomata, thereby controlling gas exchange (intake of CO₂ and release of O₂) and water loss (transpiration). When guard cells swell due to turgor pressure, the stomata open; when they lose water and become flaccid, the stomata close.

(d) What are called kitchen of the plant cell?
- Answer: The chloroplasts are called the "kitchen of the plant cell" because they are the sites where photosynthesis occurs. They contain chlorophyll, which captures light energy and converts it into chemical energy stored in glucose.

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Final Answers:

1. Fill in the blanks:
- (a) Two
- (b) Xylem
- (c) Rhizobium
- (d) Nutrients (or Food)

2. Match the following:
- (a) → (iii)
- (b) → (iv)
- (c) → (ii)
- (d) → (i)

3. Examples:
- (a) Parasitic plants: Cuscuta, Orobanche
- (b) Saprophytic plants: Monotropa uniflora, Neottia nidus-avis
- (c) Symbiotic plants: Legumes, Lichens
- (d) Fungi: Penicillium, Aspergillus
- (e) Partial parasite: Mistletoe, Dodder

4. Questions:
- (a) Nutrition: Defined above.
- (b) Photosynthesis: Defined above.
- (c) Role of guard cells: Defined above.
- (d) Kitchen of the plant cell: Chloroplasts

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Final Boxed Answers:

1. (a) Two, (b) Xylem, (c) Rhizobium, (d) Nutrients
2. (a) → (iii), (b) → (iv), (c) → (ii), (d) → (i)
3. (a) Cuscuta, Orobanche; (b) Monotropa uniflora, Neottia nidus-avis; (c) Legumes, Lichens; (d) Penicillium, Aspergillus; (e) Mistletoe, Dodder
4. (a) Defined, (b) Defined, (c) Defined, (d) Chloroplasts

Final Answer: \boxed{\text{See detailed solutions above}}