Question

Questions:

1.What type of plant movement is shown by each of Sundew, Venus Flytrap and Pitcher Plant? What is the mechanism of the movement?
2.Can a movement be both Chemonastic and Thigmonastic? If yes, so any plant in Question 1 show both?
3.Give example(s) of exclusively chemonastic and exclusively thigmonastic movement.
Description:

Sundew (Drosera sp.), Venus Flytrap (Dionaea sp.), Pitcher Plant (Nepenthes sp.) are 3 examples of Carnivorous Plants.

These plants use rapid movements to capture their prey and then digest them to fulfill their Nitrogen requirement as they grow in Nitrogen deficient soil.

My Attempts:

I have found different answers according to different sources.

1.According to one source, tentacles of both Sundew and Venus flytrap curve in response to soluble proteins placed in the centre of the leaf. So, both of them are Chemonastic.
2.According to another, Chemonasty is exhibited by long peripheral tentacles of sundew. Closing/Bending of glandular hairs of sundew in response to nitrogenous compounds.
3.According to Wikipedia, Sundew and Venus Flytrap shows thigmonasty.
4.Interestingly, none of the above sources mention Pitcher Plant. According to a friend, Pitcher Plant shows free movement (moves its leaves at its own will). Is that true?
5.Finally, according to me, all three should be thigmonastic. Because all three trap the insect once the insect touches it. So, it is influenced by touch, thus, thigmonastic. Maybe some of them are chemonastic as well (I don't know which ones).

Answer 1

The Sundew and Venus Flytrap exhibit chemonastic movement, while the Pitcher Plant uses mechanical trapping to capture insects.

Step-by-step explanation:

The Sundew, Venus Flytrap, and Pitcher Plant are all examples of carnivorous plants that exhibit different types of plant movements. The Sundew and Venus Flytrap both show chemonastic movement, which is movement in response to chemicals.

The Sundew's tentacles curve in response to soluble proteins, while the Venus Flytrap's leaves close or bend in response to nitrogenous compounds. These movements help these plants capture prey by attracting and trapping insects.

The Pitcher Plant, on the other hand, does not exhibit chemonastic movement like the Sundew and Venus Flytrap. Instead, it uses a mechanical trap, known as a pitcher, to capture insects. The opening of the pitcher is lined with a slippery wax, causing insects to slip and fall into the pool of water at the bottom of the pitcher, where they are digested.

Regarding your second question, it is possible for a movement to be both chemonastic and thigmonastic. However, none of the plants mentioned in Question 1 exhibit both chemonastic and thigmonastic movements. The Sundew and Venus Flytrap show chemonastic movement, whereas the Pitcher Plant shows mechanical trapping.

An example of exclusively chemonastic movement is the closing or bending of glandular hairs of the Sundew in response to nitrogenous compounds. An example of exclusively thigmonastic movement is the closing of the leaves of the Venus Flytrap when an insect touches the trigger hairs inside the leaves.