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.
Answer:
The given image shows - the Stomata that helps in maintaining homeostasis in the plants.
Explanation:
Stomata are the small structure resemble as tiny or pinholes that found on the underside of the leaves and play many roles in the plant. Stomata help in the gas exchange and also helps in transpiration. It allows oxygen a gas and water in vapor form from the leaves to the outer environment and let carbon dioxide inside the cell.
This system also helps in transpiration by closing and opening stomata with the help of their guard cell by becoming turgid and flaccid by osmotic pressure.
<span>Shot in the head, the victim died instantly because the bullet entered the MEDULLA, the portion of the hindbrain that regulates breathing</span>
Your answer is C lithosphere because the availability of phosphorus is different than that of carbon and nitrogen because it is found mostly at the lithosphere.
The units of evolution are populations and not individuals because a variation or a mutation in an individual is not sure to last or produce offsprings having the same variation or mutation. The proof that a species has truly evolved is when the variation has allowed the species to survive its environment and produce generations carrying the same variation.
