Answer:
Usually, Populations have a genetic variation among individuals, which is important to the population's ability to survive in different situations that have an effect on the natural selection. There are different factors which can increase or decrease the genetic diversity, and influencing natural selection.
These factors include an environmental factor, one of the major factors, which may cause changes in the genetic variation of a population and influence the natural selection. A famous and important example of environmental factors affecting natural selection was during the Industrial Revolution, when many more grey moths made up the moth population.
This was so that they could blend in with the soot from factories to avoid predators.
Answer:
A. terminators of replication.
Explanation:
For the proper transmission of genetic information from a mother cell to each daughter cell, the cell copies or replicates its chromosomes, and then splits the copied chromosomes equally to make sure that each daughter cell has a full set. And in order to duplicate and segregate correctly, chromosomes must contain three functional elements which are origins for initiation of DNA replication, the telomeres and the centromeres. Terminators of replication is not a required element.
In metaphase I of meiosis I, the pairs of homologous chromosomes, also known as bivalents or tetrads, line up in a random order along the metaphase plate. The random orientation is another way for cells to introduce genetic variation.
<span>Enzymes</span> are proteins that allow certain chemical reactions to take place much quicker than the reactions would occur on their own. Enzymes function as catalysts, which means that they speed up the rate at which metabolic processes and reactions occur in living organisms. Usually, the processes or reactions are part of a cycle or pathway, with separate reactions at each step. Each step of a pathway or cycle usually requires a specific enzyme. Without the specific enzyme to catalyze a reaction, the cycle or pathway cannot be completed.
The precambrian era makes up about 90% of the earths history, but there was little to no living organisms at the time other than microscopic ones. The first eukaryotes were found in the cambrian period after the precambrian period, not only that but at the end of the precambrian era in the Proterozoic era there was a mass extinction of about 70-80% of all living organisms
