Chapter 2 - Plants : Structure and Function
1. Give examples of 3 plants that have :
(a) spiny fruits
Ans: Jackfruit, Datura, Castor.
(b) spiny stem
Ans: Cactus, Silk floss tree, Silk cotton tree.
(c) red flowers
Ans: Hibiscus, red rose, poppy
(d) yellow flowers
Ans: sunflower, pansy, marigold
(e) leaves which close at night
Ans: Amla, Gulmohur, Rain tree
(f) single-seeded fruits
Ans: Mango, Berries, Cashew
(g) many-seeded fruits
Ans: Guava, Jackfruit, Water-melon
2. Observe any one flower and its various parts and describe it in your own words.
Ans:
The Rose Flower:
(i) The stalk is green in colour.
(ii) The leaf-like, green coloured sepals are the calyx.
(iii) The red coloured petals are called the corolla.
(iv) The androecium in a rose flower is made up of stamens, which consist of an anther and filament.
(v) The gynoecium, which is a female reproductive part of the flower, is made up of carpels, which consist of stigma, style, and ovary.
3. What are the similarities and differences between?
(a) Jowar and moong
Ans:
Similarities:
(i) Jowar and moong are both edible seeds.
(ii) Jowar and moong are both flowering plants.
Differences:
(i) Jowar is a monocotyledonous plant, whereas moong is a dicotyledonous plant.
(ii) Jowar grain is full of carbohydrates, and moong seed is full of proteins.
(iii) Jowar grains are seen in cobs. On the other hand, moong is present in legumes.
(iv) The stem of the jowar plant has no branches, whereas the stem of the moong plant shows branches.
(v) Jowar has fibrous roots under the ground and adventitious roots above the soil; however, moong has tap roots.
(b) Onion and coriander
Ans:
Similarities:
(i) Both are consumed in the form of salads.
(ii) They are used as supplementary foods in cooking and also for garnishing.
(iii) Both onions and coriander are flowering plants.
Differences:
(i) The onion is a monocotyledonous plant, whereas coriander is a dicotyledonous plant.
(ii) Onions are grown from seed or their bulb. On the other hand, coriander is grown from its seeds.
(iii) The edible onion is actually a modified leaf, but coriander leaves are leaves.
(iv) The stem of the onion is unbranched, whereas the stem of coriander shows branches.
(c) Leaves of banana and mango
Ans:
Similarities:
(i) Both the leaves have religious importance and are sacred.
(ii) Leaves of both banana and mango possess a petiole and midrib.
Differences:
(i) Banana is a monocotyledonous plant. On the other hand, mango is a dicotyledonous plant.
(ii) Banana leaf has parallel venation, whereas mango leaf has reticulate venation.
(d) Coconut tree and jowar stalk plant
Ans:
Similarities:
Both are monocotyledonous plants that yield food.
Differences:
(i) Coconut trees are strong and very tall, while the jowar stalk plant is dwarf and weak. Can be uprooted easily, unlike the coconut tree.
(ii) The coconut plant is perennial. However, the Jowar plant dies soon after the corn is grown.
(iii) Coconut trees have adventitious roots. On the other hand, jowar has adventitious and stilt roots for additional support.
4. Explain the following images in your own words.
Ans:
(i) Image A indicates maize grain. It is a monocotyledonous seed, so it cannot be divided into two equal parts.
(ii) Image ‘B’ indicates seeds. It is a dicotyledonous seed and thus can be divided into two equal parts.
5. Describe the functions of various parts of a plant.
Ans: The various parts of a plant are the root, stem, leaves, flowers, and fruits.
(i) Roots: The main function of the root is to absorb water and minerals, anchoring and supporting the plant.
(ii) Stem: The stem carries water and minerals from the roots to other parts of the plant. Also carries food prepared by the leaves to other parts of the plant.
(iii) Leaves: Leaves prepare food by the process of photosynthesis with the help of the green coloured pigment called chlorophyll.
(iv) Flower: A flower is a productive part of a plant. It produces that and seeds as a result of fertilization.
(v) Fruit contains seeds; on maturing, seeds are released from the fruit and germinate to give rise to a new plant.
6. Certain properties are mentioned below. Find a leaf corresponding to each property and describe those plants.
leaves with smooth surface, leaves with rough surface, fleshy leaf, spines on leaf.
Ans:
(i) Leaves with a smooth surface:
Mango leaf: When we touch the lamina of a mango leaf, it appears smooth.
(ii) Leaf with a rough surface:
Fig leaf: When we touch the lamina of a fig leaf, it appears rough due to the presence of some stiff hair, like outgrowth.
(iii) Fleshy Leaf:
Aloe vera: The aloe vera leaf is modified into a storage container for water. This helps them survive in places where there is a scarcity of water.
(iv) Spines on leaf:
Pandanus (Kewda): The long leaves possess prickly spines along the edges and midrib.
7. Find the plant parts.
Ans:
