Their valency is one and both belong to the third period
What cells are you talking about?
Okay so there are two types of ERs, smooth and rough.
Rough endoplasmic reticulum contain ribosomes on the outer surface. It provides large surface area for proteinsynthesis and the synthesis of glycoproteins and also provides a pathway for the transport of materials.
Smooth ER synthesises, stores and transports lipids and carbohydrates.
Hope this helps
A. behavioral isolation is when the plant or animal acts a particular way to attract their counterparts, like mating rituals.
geographic isolation is the natural barrier preventing similar species from interacting. for example, Galapagos Islands are the only home of flightless cormorants because the islands are so far from any other land for them to invade.
Temporal isolation is when two of the same or similar species cannot reproduce as a result of mismatched sexual maturity.
B. the isolation of two frog species by mating call is behavioral isolation.
Because we all came from two people bible wise. Evolution wise, same thing kinda. We all came from the same person in the beginning.