Answer:
<u>Antigenic drift</u> refers to the slow accumulation of genetic changes to an influenza virus over time.
Explanation:
Antigenic drift is defined as the mechanism by which viruses undergo variation. This mechanism involves the slow accumulation of mutations in the viral genes, that are responsible for coding the antibody binding sites. This leads to the formation of a new strain of virus, which can't be inhibited by the old antibodies. Due to this, the virus can easily spread the disease.
The antigenic drift occurs in the influenza A virus and also the influenza B viruses.
Therefore, <u>Antigenic drift refers to the slow accumulation of genetic changes to an influenza virus over time.</u>
Answer:
The given figure depicts the process of translation.
Translation is the process by which the mRNA is deciphered into the amino acid sequence of the polypeptide chain.
Ribosomes serve as the site of the translation.
The small and large subunits of the ribosome form the complex around the start codon of the mRNA.
It created three sites namely; A, P and E sites.
A site is a site where the charged tRNA enters the complex.
It then adds the amino acid specific to the codon sequence of the mRNA to the growing polypeptide chain at P site.
Uncharged tRNA then leave the complex through E site.
Answer:
a) 28 cases
b) 3 cases
Explanation:
a) From the table of genetic codes, there are 28 codons that specify more than one amino acid assuming only the first two nucleotides are considered. In these cases, one cannot outrightly specify the amino acid the genetic codes are coding for without knowing the last nucleotide of the codes. <em>For example, UU can be for Phenylalanine or Leucine, CA can be for Histidine or Glutamine, etc. </em>
b) From the table of genetic codes, the first two nucleotides of Arginine can be either of CG or AG, that of Serine can be either of UC or AG while that Leucine can be either of CU or UU. Only in these <u>3 cases</u> would one fail to know which are the first two nucleotides assuming the name of the amino acids are given.
<em>See the attached image for the genetic code.</em>
Answer:
That there used to be an abundance of plants and animals that lived there. Does this help?
Explanation:
Coal forms from dead things from the past being subjected to high pressure.