Answer:
The overall concentration of hydrogen ions is inversely related to its pH and can be measured on the pH scale . Therefore, the more hydrogen ions present, the lower the pH; conversely, the fewer hydrogen ions, the higher the pH.
Restriction enzymes can also be used to generate compatible ends on PCR products. In all cases, one or more restriction enzymes are used to digest the DNA resulting in either non-directional or directional insertion into the compatible plasmid. The most common Type II enzymes are those like HhaI (NEB #R0139), HindIII (NEB #R0104), and NotI (NEB #R0189)
The Cretaceous–Paleogene (K–Pg) extinction event (also known as the Cretaceous–Tertiary (K–T) extinction) was a sudden mass extinction of three-quarters of the plant and animal species on Earth, approximately 66 million years ago.
Answer:
directional selection
Explanation:
Directional selection is the most common type of natural selection and occurs when some individuals with characteristics favorable to the conditions of the environment in which they live, have survival advantages over individuals who do not have this advantage, who end up dying.
Imagine, for example, a graph showing the directional selection in the same species of moths. Moths of the same species have white and brown collations, in summer, brown moths can camouflage themselves on tree trunks, while white moths cannot and are easily captured by their predators, which means that the amount of white moths decrease. In this graph, the population of white moths would be at a minimum, at the same time that the population of brown moths would be at maximum.
However, with the arrival of the reverse, snow begins to cover the trees, allowing white moths to camouflage themselves more easily. The brown moths, then, are very exposed to predators, causing their population to reach the minimum while the population of white moths reaches the maximum.
The answer is <em>A.) You have antibodies that already recognize the virus</em>
Viruses and diseases are always changing. When we get sick with say the flu, a virus, or the cold of sorts, our body attacks it until it fights off the disease. You can't get sick from the same strand of sickness because once your body defeats the virus, it knows how to protect the body from it because of the antibodies, so the virus ends up evolving to get past your immune system again.
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