<span>1. Breathing moves air in and out of the lungs.
2. Oxygen diffuses from alveoli in the lungs into capillaries.
3. Oxygen enters red blood cells, where it binds to the protein hemoglobin.
4. Oxygen diffuses from the blood to the body's tissues, and carbon dioxide diffuses from the tissues to the blood.
5. Carbon dioxide leaves the body when exhale.</span>
<span>During JURASSIC period the first true mammals appear.</span>
Answer:
C. Both light tan and dark tan body color provided an advantage to the crabs on this beach, but not necessarily in other crab habitats.
Explanation:
The changes in the number of light tan and dark tan body color of crabs that occured can be described as a diversifying or disruptive selection.
This disruptive selection occurs when individuals with extreme traits on both ends of the spectrum become selected against individuals of ntermediate or medium traits.
In the case of the crab, their environment favors the selection of both extreme values as against those intermediate individuals, as both light tan and dark tan body color of the crabs gives them advantage over others in this particular environment. This may only be obtainable in this environment or similar beach environment with the same settings and conditions.
Temperature, pressure and composition.
Answer:
Explanation:
Pharmacophore (pharmacology) - The molecular framework responsible for a drug's biological activity. According to IUPAC — A pharmacophore is the ensemble of steric and electronic features that is necessary to ensure the optimal supramolecular interactions with a specific biological target structure and to trigger (or to block) its biological response.
Privileged structures are defined as molecular frameworks which are able of providing useful ligands for more than one type of receptor or enzyme target by judicious structural modifications.
1) The 1,4-dihydropyridine ring is present in many biologically important molecules that acts as an important scaffold for cardiovascular drug - a calcium antagonists and although it is technically not considered as a pharmacophore, it is considered as a privileged structure.
1,4-Dihydropyridine (DHP), belongs to the class of calcium antagonist that inhibits the influx of extracellular Ca+2 through the L-type voltage-dependent calcium channels.
A positional substitution in the 4-position is feasible in the heterocyclic ring which in turn culminates in various calcium channel antagonist activities and this heterocyclic ring is the common feature for various pharmacological activities such as anti-inflammatory activity, analgesic activity,
antihypertensive, antianginal, antitumor, antitubercular activity and antithrombotic .
Position on the heterocyclic ring binds to the L-type channel and also to N-type channel on membranes.
2.) The bioisosteres are not a suitable bioisostere for the traditional C-4 aryl or heteroaryl substitution which is necessary for calcium ion blockage thereby inhibiting it to function with the mechanism shared above.
