In 1940 Matthew and Marion Stirling found basalt altars at the site of La Venta.
Matthew Stirling was an ethnologist and archaeologist that was sent on expeditions to the Mexican Gulf Coast area to further research the <span>Olmec culture. It was in then years around 1940 that he found with his wife, Marion, several sculptures and monuments in that area. In 1940 he found several altars in La Venta.</span>
That would be Artificial Selection.
Answer:
Ligand-receptor interaction is the first interaction that triggers cell signalling.
Ligands are the hormones, drugs or neurotransmitters that specifically bind with receptors present in cell surface to initiate cell signalling. Ligand binding to the receptor is reversible. Binding of the ligand to the receptor can activate or inactivate receptor. Activation may lead to cell signalling pathways. Inside cells, there are secondary molecules which on activation starts a cascade of reactions. which in-turn regulate the function of the ligand molecule.
At first, the activated receptor relates with G proteins molecules in the cell.
before the ultimate physiological effect of the ligand on the cell's behavior is produced Therefore, the cellular signaling starts as soon as the first messenger (the ligand) binds to its receptor.
hope this helps
Answer:
Open channels allow an influx of sodium ions into the cytoplasm of the muscle fiber. The sodium influx also sends a message within the muscle fiber to trigger the release of stored calcium ions. The calcium ions diffuse into the muscle fiber.
Explanation:
