Tessarae
is the correct answer
Layer 2 would be most likely to have organisms that lived at the same time as the bird species
Answer:
it was only 90 percent effective
Explanation:
In 1954 a massive controlled field trial was launched, sponsored by the National Foundation for Infantile Paralysis. Almost two million U.S. children between the ages of six and nine participated. In some areas of the country half of these “Polio Pioneers” received the vaccine, while half received a placebo. In other areas of the country children who did not receive any vaccine were carefully observed. On April 12, 1955, Thomas Francis, Salk’s mentor and the director of the trial, reported that the vaccine was safe, potent, and 90% effective in protecting against paralytic poliomyelitis.
Answer: operon
Explanation:
An operon is a cluster of genes that are transcribed together to give a single messenger RNA (mRNA) molecule, which therefore encodes multiple proteins (Fig. 16.11). Such polycistronic mRNA is typically found in prokaryotes.
