Answer:
The right answer to this question is option D. Convergent evolution.
Explanation:
Convergent evolution is a process defined by when an organism develops the same, or at least near that, characteristics, for a specific reason, but they don't have the same origin. In this case, the cacti in both deserts have pretty much the same characteristics, and this happens because both these plants need water to survive, and in order to save it, they have barrel-shaped stems, short-lived leaves, and spines. All of these things help them in saving the water and capturing it when it's possible.
The convergent evolution is when both these organisms develop equally, but are not originally from the same place, the environment being the one to shape this.
Answer:
The correct answer is option - C. They replaced carbon dioxide with oxygen in the atmosphere.
Explanation:
Cyanobacteria or Blue-green algae is a group of bacteria that is making its own food using water and carbon dioxide in the presence of sunlight, the process of photosynthesis
These organisms release oxygen as a byproduct of photosynthesis in the atmosphere. Through this process, these organisms replaced carbon dioxide with oxygen in the atmosphere in the early earth.
Thus, the correct answer is option C. They replaced carbon dioxide with oxygen in the atmosphere.
The answer is A. Uses too much energy.
Alleles can disappear from a population through natural selection. This relates to the most fit phenotype because the breed with the desirable trait, or the most fit, will live and produce off spring. Eventually the less desirable trait and its corresponding allele will disappear after multiple generations pass. If the environment does not change alleles of non desirable traits will disappear. <span />