Answer:
B. The ddNTPs lack a 3′ hydroxyl group.
Explanation:
Dideoxynucleotides is a family of inhibitors of the DNA polymerase, its official name is 2',3' dideoxynucleotides but they are commonly called ddNTPs. One of the main characteristics of this compound is the absence of the 3'-hydroxyl group in the deoxyribose, due to the absence of this group, it is impossible to form a phosphodiester bond between nucleotides and the DNA synthesis is stopped.
If I remember that abiotic means not living then rocks, soil, air.
Hypodermis is not a layer of the skin
Answer:
D: A density-independent factor.
Explanation:
An earthquake is a density-independent limiting factor
Simple diffusion is the process by which a substance moves across a cell membrane from an area of high concentration to an area of low concentration. Substances that move by simple diffusion are able to diffuse directly across the phospholipid bilayer of the cell membrane. These substances are generally small and neutral, as large or charged particles cannot cross the phospholipid bilayer. Some examples of molecules that move by simple diffusion are carbon dioxide and oxygen.
Facilitated diffusion is the process by which a substance moves across a cell membrane from an area of high concentration to an area of low concentration with the aid of a membrane protein. Substances that move by facilitated diffusion are not able to diffuse directly across the phospholipid bilayer of the cell membrane. These substances are generally large and/or charged. They therefore travel through a protein channel in the cell membrane along their concentration gradient. Some examples of substances that can move by facilitated diffusion are glucose, sodium ions and chloride ions.
The similarities between facilitated diffusion and simple diffusion are:
They both involve the movement of a substance across a cell membrane along its concentration gradient (from an area of high concentration to an area of low concentration).
They are both examples of passive transport, as neither requires energy from the cell to move the substance across the membrane.
