Answer:
An asteroid impact.
Explanation:
An asteroid impact is considered to have tossed rubble across the earth, killing off many species of plants and animals, 65 million years ago. Volcanic activity is involved in at least four mass extinctions, whereas an asteroid in just one.
Mercury, due to it's low gravity it would not be able to hold a very strong atmosphere.
Answer:
The correct option is A. Steroid hormones exert their action by entering the nucleus of a cell and initiating or altering the expression of a gene.
Explanation:
Steroid hormones are derived from cholesterol and regulate multiple biological processes. All steroid hormones exert their action by crossing the plasma membrane and by binding with their respective intracellular receptors. They stimulate cell growth in a very different way, their lipophilic nature gives them the ability to cross lipid barriers, so, without the need for extracellular signals, these hormones can easily enter the cell, cross the cytoplasm and reach the nucleus. There they bind to specific receptors that are associated with DNA promoter regions, modifying their structure and promoting the expression of the genes under their control.
Caro means expensive in spanish
Answer:
Trichromatic vision.
Explanation:
Trichromatic theory may be defined as the theory that posses of three independent channels that are used to convey the color information. They are derived from the three different cone cells.
The television also produce three primary colors by the use of trichromatic theory. The receptor or these colors in human are greater than three as different colors have different intensity of light. The opsin protein plays an important role in the trichromatic vision.
Thus, the answer is trichromatic vision.
