Exercise Solutions Available
Step-by-step answers for all textbook questions in this chapter
NCERT Solutions for Class 6 Science Chapter 7 — Getting to Know Plants
Key Concepts
| Term | Definition |
|---|---|
| Herb | A small plant with a soft, green stem; usually short-lived (e.g., mint, tomato, grass) |
| Shrub | A medium-sized plant with a woody stem that branches near the base (e.g., rose, hibiscus) |
| Tree | A tall plant with a thick woody trunk and branches that grow above the ground (e.g., mango, neem) |
| Taproot | A main root with smaller lateral roots growing from it; found in dicots (e.g., mustard, carrot) |
| Fibrous root | A cluster of thin roots of similar size growing from the base of the stem; found in monocots (e.g., grass, wheat) |
| Stem | The part of the plant that supports branches, leaves, flowers, and fruits; conducts water and food |
| Leaf | A flat green structure that makes food through photosynthesis |
| Photosynthesis | The process by which green plants make food using sunlight, carbon dioxide, and water |
| Transpiration | The loss of water from leaves through stomata in the form of water vapour |
| Stomata | Tiny pores on the surface of leaves through which gas exchange and transpiration occur |
| Sepal | The green leaf-like structure that protects the flower bud |
| Petal | The colourful part of the flower that attracts insects for pollination |
| Stamen | The male reproductive part of a flower consisting of anther and filament |
| Pistil (Carpel) | The female reproductive part of a flower consisting of stigma, style, and ovary |
Intext Questions (Page-by-Page)
Intext Question 1 (Page 64)
Q: Correct the following statements and rewrite them in your notebook.
(a) Stem absorbs water and minerals from the soil.
Correction: Root absorbs water and minerals from the soil.
The root system of a plant is responsible for absorbing water and minerals from the soil. The root hairs increase the surface area for absorption. The stem's function is to transport these substances upward to the leaves and other parts.
(b) Leaves hold the plant upright.
Correction: Stem holds the plant upright.
The stem provides structural support to the plant, holding it upright. It also supports the branches, leaves, flowers, and fruits. Leaves are flat structures that primarily make food through photosynthesis.
(c) Roots conduct water to the leaves.
Correction: Stem conducts water to the leaves.
While roots absorb water from the soil, it is the stem that conducts (transports) water upward to the leaves through its vascular tissues (xylem). The roots pass the absorbed water to the stem for upward transport.
(d) The number of petals and sepals in a flower is always equal.
Correction: The number of petals and sepals in a flower may or may not be equal.
In many flowers, petals and sepals are equal in number, but this is not a universal rule. Some flowers have different numbers of petals and sepals. For example, mustard flowers have 4 petals and 4 sepals (equal), but in some other flowers they may differ.
(e) If the petals of a flower are joined together, then the pistil is joined to the petal.
Correction: If the petals of a flower are joined together, the pistil may or may not be joined to the petals.
The joining of petals does not determine whether the pistil is joined to the petals. These are independent features. In some flowers like hibiscus, the pistil is joined to the petal base, while in others it is free.
Intext Question 2 (Page 66)
Q: Draw the leaf and label its parts.
A leaf has the following main parts:
1. Petiole (Leaf stalk): The stalk that attaches the leaf blade to the stem. It connects the leaf to the branch. 2. Lamina (Leaf blade): The broad, flat, green part of the leaf. This is the main surface area for photosynthesis. 3. Midrib: The main vein running through the centre of the lamina from the petiole to the tip. 4. Veins: The network of thin lines on the lamina that provide support and transport water and food. 5. Veinlets: Smaller branches of veins that form a network throughout the lamina.
Types of leaf venation:
- Reticulate venation: Veins are arranged in a net-like pattern (e.g., mango, peepal). Found in plants with taproots.
- Parallel venation: Veins run parallel to each other from base to tip (e.g., grass, wheat). Found in plants with fibrous roots.
Intext Question 3 (Page 68)
Q: Can you find out the relation between the type of venation and the type of root in plants?
Yes, there is a definite relationship between the type of venation and the type of root:
| Venation Type | Root Type | Examples |
|---|---|---|
| Reticulate venation | Taproot | Mango, peepal, mustard, gram |
| Parallel venation | Fibrous root | Grass, wheat, rice, maize |
Rule:
- Plants with reticulate venation in their leaves have taproots.
- Plants with parallel venation in their leaves have fibrous roots.
This relationship helps us identify the root system by examining the leaf venation, and vice versa.
Intext Question 4 (Page 70)
Q: What are the functions of the stem?
The stem performs the following important functions:
1. Support: It holds the plant upright and supports branches, leaves, flowers, and fruits. 2. Transport of water and minerals: It conducts water and minerals absorbed by the roots upward to the leaves and other parts of the plant through xylem. 3. Transport of food: It carries food (glucose) made in the leaves to other parts of the plant through phloem. 4. Storage: In some plants, the stem stores food (e.g., potato, ginger). 5. Reproduction: In some plants, the stem helps in vegetative reproduction (e.g., stems of sugarcane, rose).
Intext Question 5 (Page 72)
Q: Which of the following leaves have reticulate venation and which have parallel venation?
Wheat, tulsi, maize, grass, coriander (dhania), China rose
| Plant | Venation Type | Root Type |
|---|---|---|
| Wheat | Parallel venation | Fibrous root |
| Tulsi | Reticulate venation | Taproot |
| Maize | Parallel venation | Fibrous root |
| Grass | Parallel venation | Fibrous root |
| Coriander (dhania) | Reticulate venation | Taproot |
| China rose | Reticulate venation | Taproot |
How to identify: To determine the venation, look at the pattern of veins on the leaf. If veins form a net-like (branching) pattern, it is reticulate venation. If veins run side by side from base to tip, it is parallel venation.
Intext Question 6 (Page 73)
Q: What are the functions of leaves?
Leaves perform the following important functions:
1. Photosynthesis: Leaves make food for the plant using sunlight, carbon dioxide, and water. Chlorophyll (the green pigment) captures sunlight energy. This process is called photosynthesis. 2. Transpiration: Leaves lose excess water through tiny pores called stomata. This process is called transpiration. It helps in cooling the plant and pulling water up from the roots. 3. Gas exchange: Stomata on the leaf surface allow the exchange of gases — carbon dioxide enters the leaf for photosynthesis, and oxygen exits as a byproduct. 4. Storage: In some plants, leaves store food and water (e.g., onion, aloe vera).
Intext Question 7 (Page 75)
Q: Explain the process of photosynthesis.
Photosynthesis is the process by which green plants make their own food using sunlight, carbon dioxide, and water.
Process of photosynthesis:
1. Absorption of sunlight: The green pigment called chlorophyll present in leaves absorbs sunlight energy. 2. Absorption of carbon dioxide: Carbon dioxide from the air enters the leaves through tiny pores called stomata. 3. Absorption of water: Water is absorbed by the roots from the soil and transported to the leaves through the stem. 4. Chemical reaction: Using the energy from sunlight, chlorophyll converts carbon dioxide and water into glucose (food) and oxygen.
Word equation: Carbon dioxide + Water + Sunlight energy → Glucose (food) + Oxygen
Conditions necessary for photosynthesis:
- Sunlight (energy source)
- Chlorophyll (green pigment)
- Carbon dioxide (from air)
- Water (from soil)
Products of photosynthesis:
- Glucose (food for the plant)
- Oxygen (released into the air through stomata)
Intext Question 8 (Page 77)
Q: What are the main parts of a flower?
A flower has the following main parts, arranged in whorls from outside to inside:
1. Sepals (Calyx): The outermost green leaf-like structures that protect the flower bud before it opens. Collectively, they are called the calyx.
2. Petals (Corolla): The colourful structures inside the sepals. They are often bright and attractive to attract insects for pollination. Collectively, they are called the corolla.
3. Stamens (Androecium): The male reproductive parts of the flower. Each stamen consists of:
- Anther: The top part that produces pollen grains (male reproductive cells).
- Filament: The thin stalk that supports the anther.
4. Pistil / Carpel (Gynoecium): The female reproductive part of the flower, located in the centre. It consists of:
- Stigma: The sticky top surface that receives pollen grains.
- Style: The thin tube connecting the stigma to the ovary.
- Ovary: The swollen base that contains ovules (female reproductive cells). After fertilisation, the ovary develops into a fruit and ovules develop into seeds.
Intext Question 9 (Page 79)
Q: What is transpiration?
Transpiration is the process by which plants lose water in the form of water vapour through tiny pores called stomata on the surface of leaves.
Key points about transpiration:
1. Where it occurs: Through stomata (tiny pores) present mainly on the lower surface of leaves. 2. What happens: Water absorbed by roots travels up through the stem to the leaves. Excess water is released as water vapour through stomata. 3. Importance:
- It helps cool the plant.
- It creates a suction pull that helps draw water up from the roots through the stem.
- It helps in the transport of water and minerals from roots to all parts of the plant.
- It maintains the water balance in the plant.
Activity to observe transpiration: Cover a potted plant with a clear polythene bag. After a few hours, you will see water droplets on the inner surface of the bag. These droplets are from transpiration.
Intext Question 10 (Page 80)
Q: How do roots help the plant?
Roots perform the following important functions:
1. Anchorage: Roots anchor the plant firmly to the soil, preventing it from being blown away by wind or washed away by water. 2. Absorption: Roots absorb water and minerals from the soil. Root hairs increase the surface area for better absorption. 3. Storage: In some plants, roots store food (e.g., carrot, radish, sweet potato). 4. Prevention of soil erosion: Roots bind the soil particles together, preventing soil erosion. 5. Transport: Roots transport the absorbed water and minerals upward to the stem.
Exercise Questions and Answers
Q1. Correct the following statements and rewrite them in your notebook:
(a) Stem absorbs water and minerals from the soil.
Correction: Root absorbs water and minerals from the soil.
Roots have root hairs that absorb water and dissolved minerals from the soil. The stem's role is to conduct these substances upward to the leaves.
(b) Leaves hold the plant upright.
Correction: Stem holds the plant upright.
The stem provides structural support and holds the plant upright. Leaves are the flat green structures that make food.
(c) Roots conduct water to the leaves.
Correction: Stem conducts water to the leaves.
While roots absorb water, the stem conducts (transports) water from roots to leaves through xylem vessels.
(d) The number of petals and sepals in a flower is always equal.
Correction: The number of petals and sepals in a flower is not always equal.
In some flowers, petals and sepals may be equal in number, but in others they differ. There is no fixed rule.
(e) If the petals of a flower are joined together, then the pistil is joined to the petal.
Correction: If the petals of a flower are joined together, the pistil may or may not be joined to the petal.
The fusion of petals does not determine whether the pistil is fused to them. These are independent structural features.
Q2. Fill in the blanks:
(a) The process of making food by plants using sunlight is called \_\_\_\_\_.
Green plants make their food using sunlight, carbon dioxide, and water through the process of photosynthesis.
(b) The tiny pores on the lower surface of leaves are called \_\_\_\_\_.
Stomata are small openings on the leaf surface through which gas exchange and transpiration occur.
(c) The part of the plant that holds it upright is the \_\_\_\_\_.
The stem provides support and holds the plant upright. It also supports branches, leaves, flowers, and fruits.
(d) The part of the leaf that attaches it to the stem is called the \_\_\_\_\_.
The petiole is the stalk of the leaf that connects the leaf blade (lamina) to the stem.
(e) The broad green part of the leaf is called the \_\_\_\_\_.
The lamina is the broad, flat, green part of the leaf where photosynthesis mainly takes place.
Q3. Can you identify the type of root shown in the figure without pulling it out from the soil? How?
Yes, we can identify the type of root without pulling the plant out of the soil by observing the leaf venation:
- If the plant has reticulate venation (net-like pattern of veins) in its leaves, it has a taproot system.
- If the plant has parallel venation (veins running parallel from base to tip) in its leaves, it has a fibrous root system.
Examples:
- A mango tree has reticulate venation → it has a taproot.
- A wheat plant has parallel venation → it has fibrous roots.
This relationship between leaf venation and root type is a reliable way to determine the root system without disturbing the plant.
Q4. Name the parts of the plant that produce food. State the conditions necessary for this process.
Parts that produce food: Leaves are the main parts of the plant that produce food through photosynthesis. In some plants, young green stems also carry out photosynthesis.
Conditions necessary for photosynthesis:
1. Sunlight: Provides energy for the chemical reaction. Without sunlight, photosynthesis cannot occur. 2. Chlorophyll: The green pigment in leaves that captures sunlight energy. Only green parts of plants can perform photosynthesis. 3. Carbon dioxide: Absorbed from the air through stomata. It is one of the raw materials for making food. 4. Water: Absorbed from the soil by roots and transported to the leaves through the stem. It is the other raw material.
Word equation: Carbon dioxide + Water + Sunlight energy (in presence of Chlorophyll) → Glucose + Oxygen
Q5. Differentiate between taproot and fibrous root.
| Feature | Taproot | Fibrous Root |
|---|---|---|
| Structure | One main root with smaller lateral roots | Many thin roots of similar size growing from the base |
| Shape | Grows deep into the soil | Spreads close to the surface |
| Depth | Penetrates deep into the soil | Does not go deep into the soil |
| Examples | Mustard, carrot, radish, mango, neem | Grass, wheat, rice, maize, onion |
| Venation type | Found in plants with reticulate venation | Found in plants with parallel venation |
| Identification | Has a prominent main root | No single prominent root |
Q6. Write the names of the parts of a flower.
A flower has the following parts arranged from outside to inside:
1. Sepals (Calyx): Green, leaf-like structures that form the outermost whorl. They protect the flower bud before it opens.
2. Petals (Corolla): Brightly coloured structures that form the second whorl. They attract insects and birds for pollination.
3. Stamens (Androecium): The male reproductive parts. Each stamen has:
- Filament: A thin stalk that supports the anther.
- Anther: The top part that produces pollen grains.
4. Pistil / Carpel (Gynoecium): The female reproductive part at the centre. It has:
- Stigma: The sticky top surface that receives pollen.
- Style: A thin tube connecting stigma to ovary.
- Ovary: The swollen base containing ovules (which develop into seeds after fertilisation).
Q7. Which of the following plants have taproots and which have fibrous roots?
(a) Wheat — Fibrous root (Wheat has parallel venation, so fibrous root)
(b) Mango — Taproot (Mango has reticulate venation, so taproot)
(c) Grass — Fibrous root (Grass has parallel venation, so fibrous root)
(d) Neem — Taproot (Neem has reticulate venation, so taproot)
(e) Mustard — Taproot (Mustard has reticulate venation, so taproot)
(f) Rice — Fibrous root (Rice has parallel venation, so fibrous root)
(g) Carrot — Taproot (Carrot has reticulate venation; the taproot is swollen and stores food)
(h) Onion — Fibrous root (Onion has parallel venation, so fibrous root)
Q8. What is the difference between herbs, shrubs, and trees?
| Feature | Herbs | Shrubs | Trees |
|---|---|---|---|
| Size | Small, short | Medium | Tall |
| Stem | Soft, green, thin | Woody, hard | Thick, woody trunk |
| Branches | May or may not branch | Branches near the base | Branches higher up on trunk |
| Lifespan | Short-lived (1-2 seasons) | Longer than herbs | Long-lived (many years) |
| Examples | Mint, tomato, wheat, grass | Rose, hibiscus, lemon | Mango, neem, banyan, peepal |
Q9. What is the function of the stem in a plant?
The stem performs the following functions:
1. Support: The stem holds the plant upright and supports the branches, leaves, flowers, and fruits. 2. Transport of water and minerals: The stem carries water and minerals from the roots to the leaves and other parts of the plant. 3. Transport of food: The stem carries food (glucose) produced by the leaves to all parts of the plant. 4. Storage: In some plants, the stem stores food and water (e.g., potato stores food in underground stems, sugarcane stores sugar in its stem). 5. Reproduction: Some plants can grow new plants from stem cuttings (e.g., rose, sugarcane).
Q10. What is transpiration? Why is it important for plants?
Transpiration is the process by which plants lose water in the form of water vapour through stomata (tiny pores) on the surface of leaves.
Why transpiration is important:
1. Cooling effect: Transpiration cools the plant, just as sweating cools our body. 2. Suction pull: The loss of water from leaves creates a suction pull that helps draw water upward from the roots through the stem. 3. Transport of minerals: As water moves upward, it carries dissolved minerals from the soil to all parts of the plant. 4. Water balance: Transpiration helps maintain the water balance in the plant by removing excess water. 5. Maintaining turgidity: It helps maintain the turgidity of cells, keeping the plant firm and upright.
Multiple Choice Questions (MCQs)
Common Mistakes to Avoid
| # | Mistake | Correction |
|---|---|---|
| 1 | Confusing herbs and shrubs | Herbs have soft green stems and are short (mint, tomato). Shrubs have woody stems and branch near the base (rose, hibiscus) |
| 2 | Saying roots conduct water to leaves | Roots absorb water; the stem conducts (transports) water to the leaves |
| 3 | Confusing taproot and fibrous root | Taproot has one main root with lateral branches (mustard). Fibrous root has many thin roots of similar size (grass) |
| 4 | Thinking petals and sepals always have equal numbers | The number of petals and sepals may or may not be equal — there is no fixed rule |
| 5 | Confusing stamen and pistil | Stamen is the male part (anther + filament). Pistil is the female part (stigma + style + ovary) |
Exam Checklist
- [ ] Can you distinguish between herbs, shrubs, and trees with examples?
- [ ] Can you identify taproot and fibrous root systems with examples?
- [ ] Can you relate leaf venation (reticulate/parallel) to root type (taproot/fibrous)?
- [ ] Can you label the parts of a leaf (petiole, lamina, midrib, veins)?
- [ ] Can you explain the process and conditions for photosynthesis?
- [ ] Can you define transpiration and explain its importance?
- [ ] Can you name and describe all four parts of a flower?
- [ ] Can you differentiate between stamen (male) and pistil (female)?
- [ ] Can you list the functions of the stem?
- [ ] Can you list the functions of the root?
Quick Reference: Plant Classification
| Type | Stem | Size | Branches | Examples |
|---|---|---|---|---|
| Herb | Soft, green | Small, short | May or may not branch | Mint, tomato, wheat, grass |
| Shrub | Woody, hard | Medium | Branch near the base | Rose, hibiscus, lemon |
| Tree | Thick, woody trunk | Tall | Branches higher up | Mango, neem, banyan, peepal |
Quick Reference: Root-Venation Relationship
| Venation Type | Root Type | Examples |
|---|---|---|
| Reticulate (net-like) | Taproot | Mango, peepal, mustard, gram, carrot |
| Parallel (side by side) | Fibrous root | Grass, wheat, rice, maize, onion |
Quick Reference: Flower Parts
| Part | Whorl | Function |
|---|---|---|
| Sepals | Calyx (outermost) | Protect the flower bud |
| Petals | Corolla | Attract insects for pollination |
| Stamens | Androecium | Male part — anther produces pollen, filament supports anther |
| Pistil | Gynoecium (innermost) | Female part — stigma receives pollen, style connects to ovary, ovary contains ovules |