Valence Electrons are on the outer shell of a atom. The outer shell is also known as the valence shell so outer electrons or valence electrons are on the outer shell or valance shell.
Answer:The Ozone Hole. One billion years ago, early aquatic organisms called blue-green algae began using energy from the Sun to split molecules of H2O and CO2 and recombine them into organic compounds and molecular oxygen (O2). ... As oxygen in the atmosphere increased, CO2 decreased.
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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Answer:
During telophase, a nuclear membrane forms around each set of chromosomes to separate the nuclear DNA from the cytoplasm.
Explanation:
Hope this helped Mark BRAINLIEST!!!
The answer would have to be A! Angiosperms!
Bryophytes had appeared in the Ordovician period, while Gymnosperms appeared in the Paleozoic era! I hope all is well, and you pass! (: Good luck, rockstar! (: