The correct answer is "they allow traffic to proceed at the speed limit".
First of all, letter B is incorrect as the main function of the speed humps is not to bring harm to the motorists but to ensure the safety of the flow of the traffic. Letter A is correct as speed humps makes the motorists slow down on purpose for the traffic to proceed at a certain speed limit.
Though both are unicellular, bacteria doesn’t possess a nucleus or cell organelles, except ribosomes, whereas amoebas possess a well-defined nucleus and all essential cell organelles.
Answer:
Ligand A and ligand B can cause same cellular responses in a cell when they are attached to different receptors.
Explanation:
If two same ligands are attached to two different receptors, two different responses will occurs. Such type of response is present in acetylcholine, while when two different ligands attached to two different receptors, same response will occur. This type of response is present in glucagon and epinephrine etc. ligands are responsible for controlling the transcription process when it binds or attached to the DNA molecule of the cell.
Answer:
Threonine has two chiral centers.
The correct options are c. carbon b and d. carbon c
Explanation:
Chiral centers are those that have four different groups of atoms bonded to it. Carbon a has three atoms of hydrogen attached to it so it can't be a chiral carbon. It isn't the carboxyl carbon either since it is double bonded to oxygen. And the amino nitrogen does not qualify anyway because it is bonded to three different groups of atoms, not four.