I would say photosynthetic bacteria are the most important, because if they disappeared most of the oxygen in the atmosphere wouldnt be here and complex life like humans wouldnt exist
<h3><u>Answer;</u></h3>
That parental traits that were not observed in the F1 reappeared in the F2.
<h3><u>Explanation</u>;</h3>
- Mendel accounted for the observation that traits which had disappeared in the F1 generation reappeared in the F2 generation by proposing that traits can be dominant or recessive, and the recessive traits were obscured by the dominant ones in the F1.
- <em>I</em><u><em>t was important that Mendel examined not just the F1 generation in his breeding experiments, but the F2 generation as well, because parental traits that were not observed in the F1 reappeared in the F2.</em></u>
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.