Answer:
Mechanical isolation
Explanation:
mechanical isolation is a form of prezygotic reproductive barrier, whereby similar species organisms become isolated and unable to successfully interbreed with each other to form zygote, as a result of incompatibility of their reproductive organ or structure, which prevents them from copulating. As a result of this, both species become separated as there is no gene flow between both.
The two species of juniper can be said to be kept separate by <em>mechanical isolation</em>, due to the differences and incompatibility of their reproductive structure.
Small bone fractures that develop in response to repetitive, cumulative trauma are known as stress fractures. These are fractures where bones are injured by overuse, they are commonly found in the spine, vertebrae, leg bones, feet, and the pelvis. They result from the accumulated trauma from repeated submaximal loading, such as running or jumping
The third one is ze answer
A gateway substance is something that may be menial but could lead to something bigger, an example is weed in the drugs world, weed is not hard to get and is usually a gateway drug to stronger types of drugs and potentially more dangerous
