When it is said that mutation is the ultimate source of genetic variation it means that it creates several new combinations which is similar to meiosis and fertilization because <span> new alleles and genes appear. It is just about some common points.</span>
Answer:
<u>d. Transport proteins within the membrane serve as a tunnel for molecules to enter the cell.
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Explanation:
Solutes are typically moved across the cell through either passive or active transport. The cells, surrounded by a bilipid layer or plasma membrane is amphiphlic- its polar, hydrophilic lipid heads face outwards, while their non-polar hydrophobic lipid tails face inwards towards each other.
While lipid-soluble molecules move across the layer easily, it is also difficult for charged and also large molecules to move across its surface, into the cell. Transmembrane channels, <u>embedded within the membrane</u>, help to maintain selective permeability as transport proteins, pores and gated channels. Simple diffusion happens as a method of passive transport in cells through plasma membranes.
The solutes travel through the plasma membrane in the process of diffusion from regions of high concentration to regions of low concentration; this occurs without the use of energy. <u>Molecules moving against their concentration require active transport mechanism to cross the membrane</u>.
Answer:
When the positive and negative charges grow large enough, a giant spark - lightning - occurs between the two charges within the cloud. This is like a static electricity sparks you see, but much bigger. Most lightning happens inside a cloud, but sometimes it happens between the cloud and the ground.
Explanation:
Rabbit ear size tends to decrease as latitude increases. this is an example of a cline
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A cline can be described as a change of the biological trait of a species across its geographical range. A cline can be genetic for example, change in the allele frequency, or phenotypic (change in body size). The change can be shown as continuous gradation, or it can be more abrupt from one geographic region to the next.
