Answer: I would go with B. Here’s why: An index fossil is usually easily recognizable, and underwent a wide geographic distribution. What leads me to believe B is the correct answer, is because it’s something that existed “ all over the world”.
Genetic variation occurs.
Mutations are not copied over and over again.
Answer:
Replication is the process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules. DNA replication is one of the most basic processes that occurs within a cell. Each time a cell divides, the two resulting daughter cells must contain exactly the same genetic information, or DNA, as the parent cell. To accomplish this, each strand of existing DNA acts as a template for replication.
Replication occurs in three major steps: the opening of the double helix and separation of the DNA strands, the priming of the template strand, and the assembly of the new DNA segment. During separation, the two strands of the DNA double helix uncoil at a specific location called the origin. Several enzymes and proteins then work together to prepare, or prime, the strands for duplication. Finally, a special enzyme called DNA polymerase organizes the assembly of the new DNA strands. The following description of this three-stage process applies generally to all cells, but specific variations within the process may occur depending on organism and cell type.
Answer:
Global sea levels may rise due to melting of glaciers and polar ice, and thermal expansion of warmer water.
Rapid sea level rise will likely be the greatest climate change challenge to mangrove ecosystems, which require stable sea levels for long-term survival.
Answer:
We should reply by telling the health magazine that every individual in the population should try to follow 'The Recommended Dietary Allowances'. The Food and Nutrition Board of the National Research Council/ National Academy of Sciences has made the RDA which determines the estimated amount of nutrients and calories that a person should uptake in order to live in a healthy manner. It also guides about the top sources of food which can be taken to fulfill the requirements.