The small green coloured leaf-like structures seen in flowers are called sepals. While, petals are the big, coloured leaf-like structures seen in flowers.

The herb has weak green stem and it is a small plant. Shrub has thicker strong stem and the plant is bigger than the herb.

The leaf turns into blue-black colour due to the presence of starch in it.

Weeds are the unwanted plants, which grow in the fields, lawns or in pots. These plants are not grown by the farmers.

Roots help in holding the soil together. In this way, roots prevent the soil from being blown away by wind or washed away by water and help in the conservation of soil.

Yes, the leaf is called as food factory of the plant. It is because the main function of a leaf is to synthesise food through the process of photosynthesis.

The relation between type of leaf venation and type of roots is
(i) The plant having leaves with reticulate venation has tap roots, e.g. sunflower plant.
(ii) The plant having leaves with parallel venation has fibrous roots, e.g. wheat.

Yes, the stem of a plant can be compared with a street with two ways traffic because
(i) It carries water and minerals from the roots to the leaves and other parts of plant in upward direction.
(ii) It takes the prepared food by the leaves to other parts of the plant.

i) Two examples of trees - Oak and banyan (bargad).
ii) Two example of shrubs - China rose and jasmine.
iii) Two examples of herbs - Tomato and wheat.
iv) Two examples of creepers - Pumpkin and watermelon.

(a) The process demonstrated in the activity is transpiration.
(b) The activity will show best results on a bright sunny day because transpiration is maximum in sunlight.
(c) After a few hours of setting up the activity, one can observe small droplets of water inside the polythene bag.
(d) A major precaution one must take while performing the activity is that the polythene bag should be cleaned and its mouth should be sealed properly. Also, the twig should be fresh with 10-12 leaves.