Agonist/antagonist
Agonist are drugs that bind and activate a receptor with effecting the response.If the effect results in maximum response it is considered as full agonist. However if the drug that binds to the receptor results only into partial efficacy in relation to the full activation of the receptor, this is considered as partial agonist.
Antagonist are drugs that blocks a biologic response of a hormone or another drug. They usually have affinity to the receptors but has no efficacy. This drug will just inhibit the activation of the receptors by the aganist.
A single random allele from each pair of parent alleles will be passed on to the gamete.
Answer:
Species could go extinct when their environment changed if they could not adapt to the change.
They are descended from wild plants.
Probably the intertidal zone, as I reason the tides would affect life dramatically. High and low tide would affect land and ocean creatures in this zone too often where as the coastal and open oceans have constant properties.
