I think the answer is C. Hope it helps
Vertebrates do not have an exoskeleton they have backbones
Answer:
Gastrulation.
Explanation:
Zygote is formed by the fusion of the male and female gamete. The zygote undergoes the process of cleavage to form the different embryonic stages of the offspring.
Gastrulation is the important process of the pre embryonic development. The blastula get multiply and rearranged to form the gastrula. The gsatrulation process includes the formation of three germ layers also known as triploblastic embryo. The three germ layers are ectoderm, endoderm and mesoderm.
Thus, the correct answer is option (C).
Answer:
When helicase mutations occur, problems in DNA replication are found. The helicases are proteins that open the 2 strands of DNA to initiate the duplication, they are responsible for breaking the hydrogen bonds between the two DNA chains, thus separating the chains, also they have the function of repairing DNA mutations, if there is mutation in the gene that encodes them, various functions will be absent in the cell.
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.