Answer:
<em>The correct option is A) an increase in oxygen levels, which led to the extinction of many anaerobic organisms.</em>
Explanation:
Photosynthesis can be described as a process in which food (glucose) is produced by photosynthetic organisms by using carbon dioxide, water along with light energy from the sun. Oxygen is released as a by-product of this reaction. The process of photosynthesis initially allowed for oxygen gas to get accumulated in the air. This caused the rise of aerobic organisms who required oxygen for respiration. Before the photosynthesis organisms evolved, there was not enough oxygen gas on earth to support the life of aerobic organisms.
Answer:
The purine ring is built onto ribose-5-phosphate of PRPP for its de-novo nucleotide biosynthesis, while the ring structure of the pyrimidine bases are synthesized separately and then coupled to ribose-5-phosphate via the C-N glycosidic bond.
Explanation:
In the de novo synthesis of nucleotides, their metabolic precursors such as aminoacids, ribose-5-phosphate, CO₂ and NH₃ are used as starting materials.
In purine nucleotide synthesis, the ring structure is built up on ribose-5-phosphate of PRPP by addition of one or a few atoms one at a time starting with the amino group donated by glutamine until the first intermediate inosinate is synthesized.
In pyrimidine ring synthesis, orotate is first synthesized from carbamoyl phosphate and aspartate, and then is attached to ribose-5-phosphate of PRPP, before it is then converted to the common pyrimidine nucleotides starting from uridylate.
Answer:
Telophase or in other words the final phase of mitosis
Explanation:
Answer:
my guess would be binary fission, in not 100% sure
Explanation:
The Theory states if my memory is correct. All living things contain one or more cells. And all living cells Come from preexisting cells. Robert Hooke discovered the cell while, Theodor Schwann and Matthias schleiden are credited to the creation of the cell theroy
