Answer: (B) Pre-zygotic; post-zygotic.
Explanation:
Prezygotic isolation occurs before fertilization of eggs. It occurs between the two sex gametes and deter sexual reproduction between different species.
However, individuals are considered to be diverge on the phylogeny tree and different species, when they cannot reproduce.
Mechanisms of prezygotic isolation include habitat isolation, gamete isolation, mechanical isolation, behavioral isolation, and mating seasons.
Whereas, postzygotic isolation prevents the formation of fertile offspring. This phenomenon leads to production of an hybrid offspring from different species and this is a form of speciation in nature.
Mechanisms of postzygotic isolation include hybrid inviability, hybrid breakdown, and hybrid sterility.
In developed nations people have more fast food options which lead to cardiovascular disease. As well as screen time all day since this is one of the factors of cardiovascular disease. Undeveloped nations don't have fast-food or television to watch all day, since they play outside.
Answer:
the cactus
Explanation:
it has spikes that can harm the predator
Because Thomson's cathode ray tube experiments led to a very important scientific discovery, the electron.
