Which of the following is NOT a growth dependent response?
The movement of plants caused by touch stimulus is known as Thigmonasty. In this mechanosensory response, water within the cells and other cell contents apply a certain amount of force against the cell walls of the plant; this is called turgor pressure.
Closing of the carnivorous Venus flytrap leaf when it captures prey is an example of:
Nastic movements are plant movements that occur in response to environmental stimuli but unlike tropic movements, the direction of the response is not dependent on the direction of stimulus. Some examples of Nastic movements include the closing of the carnivorous Venus flytrap leaf when it captures prey or the folding of the mimosa leaf when it is disturbed.
Match the following-
Mark the odd one out:
Auxin, cytokinin and gibberellins are growth promoting plant hormones while Abscisic acid is the growth inhibitior plant hormone.
Non-directional movement of plants in response to external stimuli is called:
Nastic movements are plant movements that occur in response to environmental stimuli but unlike tropic movements, the direction of the response is not dependent on the direction of the stimulus.
Which of the following are completely absent in plants:
Plants have no brain or central nervous system, which means they can't feel anything.
Humans and animals perceive pain through sensory nerve cells. These are the same type of cells that transmit information from our senses, allowing us to smell, see, hear, taste, and touch. These cells are part of what’s called the peripheral nervous system, which includes all the body's nerves except those in the spinal cord and brain.
Peripheral nerve cells form a network that carries messages from the skin, muscles, and organs to the spinal cord and brain. The brain responds by sending back messages to the pain site that promote the healing process.
Even though plants don’t have nervous systems, they can respond to stimuli. For example, when an aphid attacks a leaf, this sends an electrical signal that goes from leaf to leaf to tell the plant to start protecting itself. But it’s important to note that responding to damage does not mean the plant is in pain.
Hormones which help in growth of plant stem:
Auxins and gibberellins help promote plant growth, particularly in stem elongation. Cytokinins promote cell division and are produced in growing areas of plants. Abscisic acid plays a role in cell dormancy and is involved in the opening and closing of the stomata on leaves. Finally, ethylene is a gas that is produced by ripening fruits.
What is the reason behind change in shape of plant cells in response to a stimulus?
Movement in a sensitive plant
(i) It occurs in response to an external stimulus like touch and shock.
(ii) Plant cells change shape by changing the amount of water.
(iii) No nerves are involved.
(iv) There is no specialized tissue in plants for conduction of information.
(v) Plant cells do not have specialized proteins.
Tropism induced by touch is called:
The movement of a plant subjected to constant directional pressure is called thigmotropism, from the Greek words thigma meaning “touch,” and tropism implying “direction.” Tendrils are one example of this. The meristematic region of tendrils is very touch sensitive; light touch will evoke a quick coiling response. Cells in contact with a support surface contract, whereas cells on the opposite side of the support expand. Application of jasmonic acid is sufficient to trigger tendril coiling without a mechanical stimulus.
The growth of pollen tube towards the ovule is due to
The growth of pollen tubes towards ovules is due to chemotropism. Chemo-tropism is growth of organisms such as bacteria and plants, navigated by chemical stimuli from outside of the organism or organism's part.