<span>Emission of a photon occurs when an electron in a higher energy level undergoes atransition to a lower energy level. The energy lost is emitted as a photon. Explain the process of absorption of light by an atom.</span>
Adam Smith described self-interest and competition in a market economy as the "invisible hand" that guides the economy. This episode of the Economic Lowdown Podcast Series explains these concepts and their importance to our understanding of the economic system.
<span>Endoplasmic reticulum (ER) is a network of interconnected sacs (cisternae). Depending on the presence of ribosomes on the surface of their membrane, ER can be rough or smooth. Smooth ER does not have ribosomes on the surface of its membrane. Smooth ER plays a part in lipid production and metabolism, as well as in the production of steroid hormones. It is also involved in detoxification of organic chemicals, products of natural metabolism, etc.</span>
The answer is <span>B. It can reproduce quickly.
A single-celled organism, as its name explains, consists of only one cell. This cell must be small because, in a large cell, it would be needed a great time for information, nutrients and other molecules to travel from one part of the cell to another (choice A. is eliminated). That small cells are able to reproduce quickly because their dimension allows them to divide to new cells quickly (even 20 minutes). Still, although it is only one cell it must maintain its structure (choice C is eliminated), and cannot tolerate all environmental conditions (choice D is eliminated).</span>
D
Because it is asking you to compare them to each other and a,b, and c are just giving you similarities