Answer:
1.) Why does menstruation begin?
A.) Period happens because of changes in hormones in the body.
2.) How long does the menstrual cycle usually last?
A.) the menstrual cycle lasts 21 to 35 days while bleeding between 2 to 7 days
<u>-TheUnknownScientist</u>
Answer:
All cells are surrounded by a cell membrane. The cell membrane is semipermeable, allowing some substances to pass into the cell and blocking others.
Explanation:
U need to utilize mirrors to build the power of sunlight based vitality for a specific gadget.
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.
<span>Tropics
A lot of rain falls there, so the possibility of acid rain and smog which can be carried by warm humid air can also form. </span>
