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.
Answer:
C
Explanation:
As shown in the picture I attached to my answer, we can see all of the tectonic plates, which make up the lithosphere. The pieces do move very slightly every year.
Answer:
The phenomenon is called convergent evolution
Explanation:
Convergent evolution is the name given to the evolutionary phenomenon whereby a similar characteristic appears independently in two unrelated species, that is, that do not have a direct common ancestor from whom they could inherit that characteristic. Similar characteristics resulting from evolutionary convergence are called analogues or homoplasms (from the Greek, “shaped in the same way”). This process is very common and can be explained by natural selection, since similar selective pressures tend to favor similar adaptations.
The unit of measurement in an ecological footprint is the global hectare.
