Question:All known organisms use genetic information to produce protein molecules via the same genetic code. This finding strongly supports the hypothesis that __________.
a) the earliest macromolecules probably arose when lightning struck an oxygen-free atmosphere
b) all organisms are descended from one or a few common ancestors
c) the genetic code readily evolves by natural selection
d) there's only one possible way to encode information in a macromolecule
Answer:
b) all organisms are descended from one or a few common ancestors
Explanation:
Protein synthesis occurs when the nucleotide sequence of the mRNA is read in the form of genetic codes. A specific genetic code specifies the same amino acid in all living beings. For example, the code "UUU" codes for phenylalanine in all the living beings irrespective of their species. This suggests that all the life forms have originated from one or few common ancestors and the genetic code has been preserved during the course of evolution of various species.
<span>Norepinephrine uses the Second
Messenger System, which means, cells signal to each other what molecules have
been released that will trigger a physiological reaction. </span>
<span>
This phenomenon is activated after the ligand (ion or molecule) is bonded to its receptor
(protein molecule), creating a variation that causes a chain-reaction, that will
finally activate the Second Messenger. The latter will activate intercellular
molecules that will be able to control the cell’s activity. </span>
The answer is, "B", "Developing country".
No; some mice may have developed lung cancer in less than 500 days of cigarette smoke exposure.
Answer: The receptor site is the location that a drug binds to, altering the function of a biomolecule.
Explanation:
The drug receptors site, are the sites where the sites where the drug molecules bind. Basically, a low number of receptors exists and the extent to which the molecules occupy their sites differ with the concentration of drug. The receptor site changes the conformation and function of the binding molecule of the drug.