Question

F. Give reasons for the following: (One mark questions)
1. Leaves are green in colour.
2. Cuscuta is known as a parasite.
3. Sundew plant eats insects.
4. Plants are known as autotrophs.
5. Leaves turn blue-black when iodine solution is put on them.
6. Photosynthesis is called so.
7. In cactus, leaves are modified into spines.​

Answer 1

Answer:

So, plants and their leaves look green because the “special pair” of chlorophyll molecules uses the red end of the visible light spectrum to power reactions inside each cell. The unused green light is reflected from the leaf and we see that light.

Cuscuta plant is called a parasite because it does not have chlorophyll and absorbs food material from the host. In this process, it deprives the host of its valuable nutrients.

The twitchy tentacles of a sundew can catapult prey into the carnivorous plant's sticky traps in a fraction of a second, researchers say. Carnivorous plants such as sundews go after meat to help them survive in the nutrient-poor soils they call home

Green plants are called autotrophs since they synthesise their own food.

The hot water kills the leaf and the alcohol breaks down the chlorophyll, taking the green color out of the leaf. When you put iodine on the leaves, one of them will turn blue-black and the other will be a reddish-brown. Iodine is an indicator that turns blue-black in the presence of starch

The leaves of cactus plant are modified into spine because it helps them to lose less water during transpiration and also protect from beings eaten by animal.

Explanation:

I am also not properly sure about the answer. But I hope it will help you somehow.