Because an antibody is "made" relative to the antigen, but kept at low levels when you are exposed the first time ("primary immune response"). The second time you're exposed to the same antigen, memory cells recognize it and the body produces a high level of antibodies, and the level of antibodies usually remains higher for a longer time ("secondary immune response"). This is your basic immune response (primary and secondary).
This explains exactly why vaccines are effective to extremely effective.
<span> For a start, when you have a question that needs answering in science, you formulate a null hypothesis. That is a negative statement which you then set out to prove or disprove. This is just a convention. So if your initial question is for example, "Does sugar dissolve in water?"
Your null hypothesis will be "Sugar does not dissolve in water."
You then set up your experiment and get some data.
Now if your data doesn't support your null hypothesis then you reject it and make the statement ,"Sugar does dissolve in water." As you can see from this simple example, a non-result is still a result so the idea of formulating new tests as mentioned by another answerer isn't necessary and in some ways is the incorrect thing to do. In science, hypotheses are often not supported by data and i would argue that this is the case a lot of the time. A non-result is still a result and you will have plenty to write about whichever way it goes. </span>
The global average atmospheric carbon dioxide in 2019 was 409.8 parts per million (ppm for short), with a range of uncertainty of plus or minus 0.1 ppm. Carbon dioxide levels today are higher than at any point in at least the past 800,000 years.The carbon cycle describes the process in which carbon atoms continually travel from the atmosphere to the Earth and then back into the atmosphere. Since our planet and its atmosphere form a closed environment, the amount of carbon in this system does not change.
Answer:
D. Columnar
Explanation:
Hint the root word is in the option and it is actually shaped like a column according to Epithelium - Wikipedia
Hope this helps : )
Answer:
Determine the parental genotypes. You can use any letter you like but select one that has a clearly different lower case, for example: Aa, Bb, Dd.
Split the alleles for each parent and add them into your Punnett square around the edges.
Work out the new possible genetic combinations inside the Punnett square.
Explanation: