Answer:
<h2>C. placing carrier proteins in the membrane.</h2>
Explanation:
If there is no barrier preventing molecules from moving molecules, then there will be large movement of molecules from an area of high concentration to an area of low concentration. This passive process is known as diffusion. The phospholipid bilayer of a cell's membrane works as a barrier to large molecules, ions, and most hydrophilic molecules. Whereas small hydrophobic molecules can pass freely through the phospholipid bilayer, other molecules and ions are transported across the cell membrane with the help of transport proteins. Some transport proteins, allowing hydrophilic molecules and ions to passively move through them and across the cell membrane.
Examples: carrier proteins and channel proteins.
Placing carrier proteins in the cell membrane will allow the molecule to reach equal concentrations on the both the sides of the membrane and maintain that way over long time. In contrast, transport proteins known as pumps will use cellular energy, usually in the form of ATP, to transport molecules.
Placing equal numbers of intracellularly directed and extracellularly directed pumps would also equalize the concentrations of a molecule long over time. Pumps are to transport molecules against their concentration gradient, such as the sodium-potassium pump continuously moves sodium ions out of a cell.
Through the use of carrier proteins, there is equalization of concentrations of a hydrophilic molecule. This equalize the numbers of molecules on the inside and outside of the cell, but the pumps would continue moving the molecule inward, eventually resulting in more molecules inside of the cell than out.
Answer:
Saturation
Explanation:
A solution with as much dissolved solute as it can hold at a given temperature is said to be saturated. The solution is homogeneous since the solute and solvent are evenly distributed in the solution. The solution is saturated however, since no more solute can dissolve at a given temperature.
Answer:
Why is internal Fertilisation important to animals?
Internal fertilization has the advantage of protecting the fertilized egg from dehydration on land. The embryo is isolated within the female, which limits predation on the young.
Explanation:
The question is incomplete as it does not have the options which are:
I. only
I. and II. only
II. and III. only
I, II, and III.
Answer:
I, II, and III.
Explanation:
The mechanism of natural selection can be explained for the trait which is determined by one gene but the traits which can be determined by more than one gene like height (polygenic trait), the selection becomes very complex.
The natural selection can be explained by the phenotype produced in a population and that depends on the genes. The polygenic trait shows the variation in the population, therefore, it is impossible to predict only one mechanism and therefore all types of natural selection occurs on a population.
Thus, I, II, and III are correct.
Answer:
complexity. (uncountable) The state of being complex; intricacy; entanglement. (countable) That which is and renders complex; intricacy; complication.
Explanation:
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