-DNA is the blueprint for proteins, which play many roles in the body. PROTEINS play many roles in the body and determine many traits. The section of DNA that codes for a specific trait is called a GENE. In fruit flies, straight wings are dominant and curly wings are recessive.
Paramecia<span> reproduce asexually, by binary fission. During reproduction, the macronucleus splits by a type of amitosis, and the micronuclei undergo mitosis. The </span>cell<span> then divides transversally, and each new </span>cell<span> obtains a copy of the micronucleus and the macronucleus.</span>
Answer:
Oxygen levels stay above 15 percent starting 200 million years ago
Explanation:
Atmospheric oxygen levels are related to the evolution on Earth and changes in geochemical cycles that involve climate variations.
The presence of O
2 and evolution of oxygen gave new opportunities to the life on Earth. Oxygen levels in atmosphere have fluctuated between 15% and 35% of atmospheric volume, since the start of the Cambrian period.
So, form the starting 200 million years ago, oxygen level stay above 15 percent and the correct option is "B".
