Answer:
Due to presence at early days of the planet.
Explanation:
We only find the remains of single celled organisms in the oldest fossils because the single celled organisms are the organisms that were present in the early days of this planet. These single celled microbes were present about 3.7 billion years ago while on the other hand, the oldest rocks are only a little older i. e. 3.8 billion years so these single celled organisms are considered as oldest fossils on this planet.
Answer:
NAD is a coenzyme found in all cells. It consists of two nucleotides linked through their phosphate groups with a nucleotide that contains an adenosine ring and another that contains nicotinamide.
Explanation:
In metabolism, NAD participates in oxidation reduction reactions. This coenzyme is found in two forms in the cells: NAD and NADH. NAD accepts electrons from other molecules and is reduced, forming NADH, which you can use as a reducing agent to donate electrons. These electron transfer reactions are the main function of the NAD.
In living organisms, NAD can be synthesized from scratch from the amino acids tryptophan or aspartic acid. Some NADs are found in nicotinamide adenine dinucleotide phosphate (NADP), whose chemistry is similar to NAD, although it has different functions in metabolism.
Yes ..................................
Elephant organism => classifying Organism
