Iodine is necessary for the synthesis of which of the following hormone ?
Iodine is an important constituent of hormone thyroxine. Its deficiency causes enlargement of thyroid gland (Goitre).
The hormone that is used to keep flowers fresh is
Cytokinins are plant hormones that cause increased cell division by stimulating the process of mitosis.Increased mitosis results in plant growth and the formation of shoots and buds, as well as the development of fruits and seeds.
Taste receptors are :
Within the structure of the papillae are taste buds that contain specialized gustatory receptor cells for the transduction of taste stimuli. These receptor cells are sensitive to the chemicals contained within foods that are ingested, and they release neurotransmitters based on the amount of the chemical in the food.
Which statement is incorrect about auxins?
The main function of auxin is to help plants grow. Auxin stimulates plant cells to elongate, and the apical meristem of a plant is one of the main places that auxin is produced.
In cucurbita growth of the tendril towards support is due to
Rapid growth in cells of tendril cells away from support results in bending of tendril towards support.
The leaves of Mimosa are sensitive to
The Mimosa plant(or touch-me-not plant) folds the leaflets on stimulus with touch. The stimulus is passed on to the entire branch and then the whole plant with all the leaflets close. There is a loss of water from the cells at the base of the leaf.
Select the mis-matched pair from the following :
Thyroxin is secreted by thyroid gland. Testes secrete male hormone testosterone.
Reflex actions are mediated through
Spinal cord acts as the main center for reflex actions. Spinal cord acts as a link between spinal nerves and brain. Thus it participates in conscious actions. Reflex actions is defined as an involuntary action performed by muscles under the direction of spinal cord in response to the stimulus.
In flowering plants the growth of the pollen tube toward ovules is an example of :
The tissues of style secrete certain chemicals and the pollen tube moves toward these chemicals.
How many pairs of cranial nerves are present in man ?
Each cranial nerve is paired and is present on both sides. There are conventionally twelve pairs of cranial nerves, which are described with Roman numerals I–XII. Some considered there to be thirteen pairs of cranial nerves, including cranial nerve zero.