Question

The flowers of Oxalis open during the day and close at night, such type of movement is
a. Photonasty
b. Nyctinasty
c. Phototactic
d. Seismonastic

Answer 1

The flowering plant which is also known as wood sorrel is Oxalis. The taste of most species of wood sorrel is acidic. The plant leaves are divided into 3-10 leaflets which are arranged palmately with all the leaflets. The flower of Oxalis consists of 5 petals that are fused at the base and contain 10 stamens.

Complete answer:

The response that is produced by the plants against light availability is called Photonasty. An example of photonastic movement is Oxalis flowers which are open during the daytime and closed during night time. Another example is of Cestrum nocturnum flowers. The photonastic movement of plants is not having a fixed direction. They move non-directionally where they get the light.

The nastic movements of the higher plant parts like leaves or petals are called nyctinasty. The sleeping movement is mainly called the Nyctinastic movement. They show their response in the darkness and grow independently. These movements are reversible and repeatable which show their response to a stimulus. For example – diurnal leaves movement like in Venus flytrap to prey.

The movement during which a whole organism moves towards or away from the light stimulus is called Phototaxis or locomotor movement. The phototactic movement of plants shows its response toward or away from the light.

The type of nastic movement that plants show in response to touch is called seismonastic movement. For example – Mimosa pudica is a plant that closes their leaves when anything touches on their leaves.

Hence, the correct answer is option (A).

Note: We have notes about the various types of nastic movements that show their response to different stimuli. Some show light response and grow towards or away from the light while others show touch response and close their plant parts if anything touches them. Oxalis flowers show the photonastic movement in which day time flower opening and night time flowering closing takes place.