Answer: c) and b) are correct.
The brain is encased in a protective bony or cartilaginous housing in craniates.
The anterior end of the nerve cord is elaborated to form a brain in craniates.
Explanation: The craniates include the chordata with well-defined heads. This includes mammals, reptiles and fishes. So we can discard the other answers. Because most craniates have functional jaws, and the adults do not lose their chordate characteristics. The last one does not apply as a specific feature because the tunicate have neural crest but are not recognized as craniata.
Addition or deletion of nucleotides in any number besides 3 results in a "frame-shift mutation."
This is because every 3 nucleotides of DNA/mRNA exons codes for a single amino acid in the synthesis of a protein. This triplet codon theory means that if 3 nucleotides are added or deleted then an amino acid will be added or lost, but subsequent codons and amino acids will still be read correctly.
However, if any number of nucleotides other than 3 are added or removed, then the codons following the mutation will be out of "sync," in terms of the reading order.
Hence it is called a frame-shift mutation because it shift the reading frame when translating nucleic acids into proteins. Frame shifts will lead to the wrong amino acids being adding in the wrong order for the rest of the code after the mutation.
The cell cycle or cell-division cycle is the series of events that take place in a cell leading to its division and duplication of its DNA (DNA replication) to produce two daughter cells. In bacteria, which lack a cell nucleus, the cell cycle is divided into the B, C, and D periods. The B period extends from the end of cell division to the beginning of DNA replication.
Answer:
Explanation:
a fungus named penicillin produces a substance that kills the bacteria near it. The mold produces the antibiotic penicillin. How do fungi help plants grow? The hyphae spread underground and absorb water and nutrients from the soil for the plant.
