🌿 Chapter Notes: Nutrition in Living Organisms – Plants
🔹 1. What is Nutrition?
-
Nutrition is the process by which living organisms obtain food and use it for:
- Growth
- Energy
- Repair of body parts
- Maintenance of life
🔹 2. Modes of Nutrition
🌱 (A) Autotrophic Nutrition
- Organisms make their own food
- Example: Green plants
- Process used: Photosynthesis
🐾 (B) Heterotrophic Nutrition
- Organisms depend on others for food
- Example: Animals
🔹 3. Photosynthesis 🌞
👉 Definition:
Photosynthesis is the process by which green plants prepare their own food using sunlight, water, carbon dioxide, and chlorophyll.
📌 Equation:
📌 Raw Materials:
- Water → from soil (absorbed by roots)
- Carbon dioxide → from air
- Sunlight → energy source
- Chlorophyll → green pigment in leaves
📌 Products:
- Glucose (food)
- Oxygen (released into air)
🔹 4. Parts Involved in Photosynthesis
🌿 Leaf – “Food Factory”
- Main site of photosynthesis
🌱 Roots
- Absorb water and minerals
🌬️ Stomata
- Tiny pores on leaves
- Help in gas exchange
🚰 Vessels (Xylem)
- Transport water and minerals
🔹 5. Types of Heterotrophic Nutrition in Plants
(A) 🌸 Saprotrophic Nutrition
- Feed on dead and decaying matter
- Example: Fungi, Mushroom
(B) 🌿 Parasitic Nutrition
- Depend on host plant for food
- Example: Amarbel (Cuscuta)
(C) 🤝 Symbiotic Nutrition
- Two organisms live together and help each other
- Example: Lichen (Alga + Fungus)
(D) 🪰 Insectivorous Plants
- Feed on insects for nitrogen
- Example: Pitcher plant
🔹 6. Special Concepts
🌍 Sun – Ultimate Source of Energy
- Plants use sunlight → make food
- Animals depend on plants → directly or indirectly
🍃 Why Leaves are Food Factories?
- Contain chlorophyll
- Perform photosynthesis
🧫 Role of Rhizobium
- Lives in roots of leguminous plants
- Converts atmospheric nitrogen into usable form
🔹 7. Important Definitions
- Photosynthesis: Food-making process in plants
- Nutrients: Components of food needed by body
- Saprotrophs: Feed on dead matter
- Symbiosis: Mutual beneficial relationship
🔹 8. Key Reasons (Very Important for Exams)
✔ Life not possible without photosynthesis → no food + no oxygen
✔ Mushroom is saprotroph → no chlorophyll
✔ Leaf dies if stomata blocked → no gas exchange
✔ Insectivorous plants → need nitrogen
🔹 10. Memory Trick 🧠
👉 "CARBON + WATER + SUN = FOOD + OXYGEN"
✅ MCQ Questions
🔹 Section A: Basic Concepts
-
The process by which organisms take food is called:
a) Respiration
b) Nutrition
c) Excretion
d) Digestion -
Green plants are called:
a) Heterotrophs
b) Parasites
c) Autotrophs
d) Saprotrophs -
Animals are:
a) Autotrophs
b) Producers
c) Heterotrophs
d) Decomposers -
The food factory of the plant is:
a) Root
b) Stem
c) Leaf
d) Flower -
Chlorophyll is present in:
a) Roots
b) Stem
c) Leaves
d) Flowers
🔹 Section B: Photosynthesis
-
Photosynthesis takes place in:
a) Roots
b) Stem
c) Leaves
d) Fruits -
Plants take in ______ during photosynthesis:
a) Oxygen
b) Nitrogen
c) Carbon dioxide
d) Hydrogen -
Plants release ______ during photosynthesis:
a) Carbon dioxide
b) Oxygen
c) Nitrogen
d) Hydrogen -
The energy source for photosynthesis is:
a) Water
b) Soil
c) Sunlight
d) Air -
The green pigment in plants is:
a) Hemoglobin
b) Chlorophyll
c) Melanin
d) Starch -
Water is absorbed by:
a) Leaves
b) Stem
c) Roots
d) Flowers -
Carbon dioxide is taken from:
a) Soil
b) Air
c) Water
d) Stem
🔹 Section C: Plant Parts & Functions
-
Tiny pores on leaves are called:
a) Xylem
b) Phloem
c) Stomata
d) Veins -
Stomata help in:
a) Water absorption
b) Gas exchange
c) Food storage
d) Reproduction -
Vessels in plants help in:
a) Digestion
b) Transport of water
c) Reproduction
d) Respiration -
Roots absorb:
a) Oxygen
b) Water and minerals
c) Food
d) Carbon dioxide
🔹 Section D: Types of Nutrition
-
Organisms that make their own food are:
a) Heterotrophs
b) Parasites
c) Autotrophs
d) Saprotrophs -
Organisms that depend on others for food are:
a) Autotrophs
b) Heterotrophs
c) Producers
d) Plants -
Fungi obtain food by:
a) Photosynthesis
b) Saprotrophic nutrition
c) Parasitic nutrition
d) Symbiotic nutrition -
Mushroom is a:
a) Autotroph
b) Parasite
c) Saprotroph
d) Producer
🔹 Section E: Special Types
-
Amarbel is a:
a) Saprotroph
b) Parasite
c) Autotroph
d) Insectivore -
Lichens show:
a) Parasitism
b) Symbiosis
c) Saprotrophism
d) Autotrophy -
Lichen is made of:
a) Two fungi
b) Alga + fungus
c) Plant + bacteria
d) Animal + plant -
Insectivorous plants feed on insects for:
a) Oxygen
b) Carbon
c) Nitrogen
d) Hydrogen -
Pitcher plant is an example of:
a) Parasite
b) Saprotroph
c) Insectivorous plant
d) Autotroph
🔹 Section F: Reason-Based MCQs
-
Leaves are called food factories because they:
a) Store food
b) Make food
c) Absorb water
d) Give oxygen -
If stomata are blocked, the leaf will:
a) Grow faster
b) Die
c) Produce more food
d) Store water -
Sun is the ultimate source of energy because:
a) It gives heat
b) It helps in photosynthesis
c) It produces oxygen
d) It absorbs carbon dioxide -
Life is not possible without photosynthesis because:
a) No sunlight
b) No plants and oxygen
c) No soil
d) No water
🔹 Section G: Microorganisms & Others
-
Rhizobium bacteria live in:
a) Leaves
b) Stem
c) Roots
d) Flowers -
Rhizobium helps plants by:
a) Producing oxygen
b) Fixing nitrogen
c) Absorbing water
d) Making food -
Saprotrophs feed on:
a) Living plants
b) Dead and decaying matter
c) Animals
d) Soil -
The foul smell in stale dough is due to:
a) Plants
b) Fungi and bacteria
c) Air
d) Water
✅ Answer Key (Row Format)
1-b, 2-c, 3-c, 4-c, 5-c,
6-c, 7-c, 8-b, 9-c, 10-b,
11-c, 12-b, 13-c, 14-b, 15-b,
16-b, 17-c, 18-b, 19-b, 20-c,
21-b, 22-b, 23-b, 24-c, 25-c,
26-b, 27-b, 28-b, 29-b,
30-c, 31-b, 32-b, 33-b
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