Answer:
The cell membrane, also called the plasma membrane, is found in all cells and separates the interior of the cell from the outside environment. The cell membrane consists of a lipid bilayer that is semipermeable. The cell membrane regulates the transport of materials entering and exiting the cell.
Explanation:
Answer:
The brick
The brick has the greater mass, therefore has the greater density. The
particles in a brick are more tightly packed together. Density is an
indication of how tightly packed the particles in the substance are
Explanation:
Surprisingly, until recently, not much was known about the genes that control melanin production. 6 were known (MC1R, TYR, OCA2, SLC24A5, MATP and ASIP) and 17 more have been recently identified (DTNBP1, GPR143, HPS3, KITGL, MLPH, MYO5A, MYO7A, SLC45A2, TYRP1, ERCC6, GNAS, HERC2, IRF4, OBSCN, SKC24A5, TPNC2 and MITF), all of them directly or indirectly related to the process of melanin formation and distribution. Since there are so many different genes, if we count all the possible alterations, many different color variants can be produced.
Answer:
It is true that studying natural selection in the fields can be challenging. Some of the challenges which Darwin might have faced could have been:
Darwin was only studying one trait for his results. But there might have been many other factors or traits affecting natural selection.
Natural selection does not happen rapidly hence Darwin would have had to wait for many generations to observe the results.
The environment is not such an easy factor to study. It is complex. It might have happened that the environment might have changed before any changes were seen in the population of the birds.
Answer:
<em>C. Increased loss of soil nutrients</em>
Explanation: