Answer:
"As a molecule moves through the plasma membrane it passes through <em>a hydrophilic layer of phospholipid heads then a hydrophobic layer of phospholipid tails and then another hydrophilic layer of phospholipid heads".</em>
Explanation:
Biological membranes are formed by two lipidic layers, proteins, and glucans.
Lipids characterize for being amphipathic molecules, which means that they have both a hydrophilic portion and a hydrophobic portion at the same time. These molecules have a lipidic head that corresponds to a negatively charged phosphate group, which is the polar and hydrophilic portion. They also have two lipidic tails that correspond to the hydrocarbon chains -the apolar and hydrophobic portion- of the fatty acids that esterify glycerol.
Membrane lipids are arranged with their hydrophilic polar heads facing the exterior and the interior of the cells, while their hydrophobic tails are against each other, constituting the internal part of the membrane.
Through this lipidic bilayer, some molecules can move from one side of the cell to the other, which happens because of concentration differences. When this occurs, molecules must pass through the hydrophilic layer of phospholipid heads then through the hydrophobic layer of phospholipid tails and then again through another hydrophilic layer of phospholipid heads.
Guard cells are located in the leaf epidermis and pairs of guard cells surround and form stomatal pores, which regulate CO2 influx from the atmosphere into the leaves for photosynthetic carbon fixation.
Stomatal guard cells also regulate water loss of plants via transpiration to the atmosphere.
The answer is B) prime meridian
It is the opposite of the equator. If you need more of and explanation please just ask.
Restoring farmlands to wetlands consists of a lot of pro and cons. Firstly, they should consider that wetlands will greatly filter carbon dioxide from the atmosphere and reduce greenhouse gases. Wetlands restoration would probably affect the lives of the nearby human residents negatively. This is due to the fact that wetlands provides an optimal habitat to wild animals especially dangerous carnivores like alligators. The regeneration project will expand the habitats of animals, and clean the water system but it will remove the nutrients from the soil.
Answer: when bright light is present, the pupil reduces in size, or flinching when feeling threatened
Explanation: i know what reflexes are :)
