Answer: Native species can be the hardest to explain. Simply put, natives are species that are from a particular place without human intervention–humans didn’t put them there directly or indirectly. Digging into that a bit means that “native” can vary a lot based on what scale one is considering, and whether or not there are records of pre-settlement organisms (think fossils). As with anything, there are lots of other names for native, like “indigenous.” Non-native species spread by natural process or human activities. ... When an exotic species becomes harmful to the ecosystem, it is called an invasive species. The main difference between exotic and invasive species is that exotic species is harmless to the ecosystem whereas invasive species is harmful to the ecosystem.
Explanation:
Do you mean REM? If so it’s an abbreviation for Rapid Eye Movement; the deepest point in your sleep where dreams occur.
Genetic variation is important because a population has a better chance of surviving and flourishing than a population with limited genetic variation. Genetic diversity also decreases the occurrence of unfavorable inherited traits.
Aphotic zone: It is an inky darkness that occupies the great bulk of the ocean.
Photic zone: its a surface layer that receives sunlight.
