Answer:
A <u><em>receptor</em></u> is a protein that recognizes and responds to a signal.
Explanation:
A receptor is a protein molecule present on the cells on which the signalling molecules can bind and generate a physiological response. Some receptor molecules can also respond to Sun and light. Each type of cell has specific receptors molecules and hence can respond to specific signals. The receptor molecules hence tend to receive signals for a cell. Molecules such as hormones bind to the receptors.
To much gas has build up in them? I guess
Answer:
Kingdom 4
Explanation:
This kingdom is the only one with the ability to be heterotrophic or autotrophic.
Answer: The correct statements are 1 and 2:
1.Self-pollination occurs when the pollen from the anther is deposited on the stigma of the same flower, or another flower on the same plant.
2.Cross-pollination is the transfer of pollen from the anther of one flower to the stigma of another flower on a different individual of the same species.
Explanation:
Pollination is the transfer of pollen grains from an anthers to a receptive stigma. In most species of flowering plants, external agents bring about pollination. Also, flowers have evolved special structures and mechanisms to ensure successful pollination.
There are two types of pollination
--> Self pollination: This takes place when mature pollen grains from the anther of a flower fall on the stigma of the same flower or that of another flower on the same plant. This type of pollination brings the male gametes and egg cells of the same plant together. The resultant offspring show very little genetic variation.
--> Cross pollination: This occurs when mature pollen grains of a flower are transferred to the stigma of a flower of another plant of the same or closely related species. This brings the male gametes and egg cells of two different parent plants together. Therefore, there is greater genetic variation among the offspring.
