The reason why nost scientists thought that the first true cells formed on Earth were anaerobic is being shown in the second option :B. because there was no oxygen on early Earth. Paying attention to this fact scientists discovered that first cells were prokaryotes and greatest part of them created oxygen as a toxic by-product of their own metabolism which make them understand how the planet was provided with oxygen and made a conclusion that first cells were anaerobic.
Since, it has a nervous system, blood vessels, and a long digestive tube is most likely a segmented worm.
<h3>What is a segmented worm?</h3>
Segmented worms have long tube-like bodies that are divided into segments.
They are the simplest organism with a true nervous system and blood contained in vessels.
They have a long digestive tube that runs down the length of the worm's inner body.
They can take in dissolved oxygen from the water through their skin.
Thus, a segmented worm has a nervous system, blood vessels, and a long digestive tube.
To learn more about a segmented worm click here:
brainly.com/question/970980
The answer is <span>A. Meiosis: It increases genetic variation, which helps ensure the species will survive.
Meiosis increases genetic variation. This means there is a great variety of genotypes among the population. Hence, there are organisms able to survive in a wider range of temperature. If </span><span>there were drastic changes in temperature in an ecosystem, some of the organisms will survive because their genotype allows them to live in such conditions. If there were no variety thanks to meiosis, all of the organisms would die. And that is not beneficial to a species.
Imagine on the other hand that mitosis occurred. Mitosis does not provide a variety of genotypes and all of the organism will be the same. </span><span>If there were drastic changes in temperature in an ecosystem, all of the organisms would die because all of them could respond to the change in the same way.</span>
Answer:
b
Explanation:
because they are held together by ester bonds not peptide bond :)