Answer:
when you are seeing thing that is not there or when you are having illusions
Explanation:
Los aminoácidos químicamente son sustancias que estan formadas como su nombre lo indica, por un grupo amino y uno carboxilo, unidos ambos a un carbono central. Recordemos que el átomo de carbono tiene valencia 4, es decir, tiene cuatro lugares para sostener enlaces. Por lo tanto el resto los puede ocupar con átomos de hidrógeno u otras cadenas carbonadas a las que simbolizamos con la letra R. R puede ser un grupo metilo o un etilo o un gruo de más carbonos o también un anillo aromático, etc
Sand particles are known to move everywhere and are a part of the geosphere
Answer:
Gas exchange occurs at two sites in the body: in the lungs, where oxygen is picked up and carbon dioxide is released at the respiratory membrane, and at the tissues, where oxygen is released and carbon dioxide is picked up.
Explanation:
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.
