Answer:
The presence of predators of deer which does not allow increase in the population of deer year after year.
Explanation:
In an forest ecosystem, one animal controls the population of another organisms and thus there is no increase in the population of that organism and the ecosystem is in equilibrium state. The population of deer did not increase due to the presence of predators such as lion, cheetah etc and the net population is 0.
Answer: 4
Explanation:
It is composed of a cell, but does not have
tissues.
<span>Chromated copper arsenate, or CCA, is a pesticide that has been used for years in
pressure-treating lumber to prevent destruction from rot and insects. Arsenic, a toxic
chemical, can leach from this treated wood, leaving residues on the wood’s surface and in
nearby soil. Young children who play on or near decks or playscapes made from CCA-
treated wood can get arsenic on their skin and into their bodies, especially if they eat or
drink without washing their hands.
Because of the health risks of long-term exposure to arsenic, the Environmental
Protection Agency (EPA) has announced that as of December 31, 2003, arsenic Currently the EPA does not recommend that people remove existing structures made with CCA-treated wood or the soil surrounding those structures. However, they do recommend that people reduce their potential exposure to arsenic.</span>
Answer:
Explanation:
The main function of the plasma membrane is to protect the cell from its surroundings. Made of a phospholipid bilayer with embedded proteins, the plasma membrane is selectively permeable to ions and organic molecules it also regulates the movement of substances in and out of cells. Plasma membranes must be very flexible in order to allow certain cells, such as red blood cells and white blood cells, to change shape as they pass through narrow capillaries. Membrane receptors provide extracellular attachment sites for effectors like hormones and growth factors, which then trigger intracellular responses. Some viruses, such as Human Immunodeficiency Virus (HIV), can intercept these receptors to get into the cells, causing infections.
