Answer:
John: he has naturally acquired active immunity to chicken pox from previous exposure.
Explanation:
Your body naturally has some immunity to things that aren't you, but when you get sick with a specific pathogen, your body begins to make antibodies that specifically recognize that pathogen. Each antibody only recognizes one pathogen, and it floats around waiting to find it again so it can tell your body to kill it before you get sick again. This is why we become immune to chicken pox; after the first time you beat it, your body has the labeled antibodies and it can quickly destroy the pathogen before you get sick again.
<span>1 Chemicals can be toxic because they can harm us when they enter or contact the body. Exposure to a toxic substance such as gasoline can affect your health. Since drinking gasoline can cause burns, vomiting, diarrhea and, in very large amounts, drowsiness or death, it is toxic. Some chemicals are hazardous because of their physical properties: they can explode, burn or react easily with other chemicals. Since gasoline can burn and its vapors can explode, gasoline is also hazardous. A chemical can be toxic, or hazardous, or both.
</span>2 Non point source<span> water </span>pollution<span> is </span>difficult to control<span> because it comes from the everyday activities of many different people, such as fertilizing a lawn, using a pesticide, or constructing a road or building.</span>
Answer:
b. skin from mouse 2
Explanation:
According to this question, a mice skin transplant is being conducted. Four mice labelled Mouse 1, Mouse 2, Mouse 3 and Mouse 4 are used for this experiment. A small patch of skin from mouse 2 (the donor) was transplanted onto mouse 1 (the recipient), however, it was eventually rejected by the recipient (mouse 1).
This transplant rejection is due to the fact that the recipient's immune system identifies the tansplanted skin as foreign, hence, begins to attack it, leading to the skin's necrosis or death. Based on this, the same transplant rejection will occur if skin patches from mouse 3 and 4 are used.
However, the immune system of mouse 1, which is the recipient, will identify skin patches from MOUSE 2 as less foreign than any other skin from other mice. This is because skin from that mouse has been used before, hence, the recipient's immune recognizes it when a follow-up transplant is conducted. This makes a follow-up transplant from MOUSE 2 be the least likely to be rejected.
Answer:
la investigación científica
