Answer:
B. Geographic Isolation
Explanation:
Speciation is a biological process that allows the generation of new species through existing species. Through conditions imposed by the environment in which this species lives.
Speciation is usually caused by geographic isolation.
Geographic isolation occurs when a population of the same species is separated by some type of natural barrier, such as rivers or mountains. This causes the population to be divided in two and begin to face different environments and different environmental conditions. This causes each part of the population to adapt in different ways, leaving them so different from one another that it is no longer possible to say that the two populations belong to the same species.
The most Senistive part of the chest
Answer:
Because the trophozoites are unable to survive outside a host.
Explanation:
The term infectious is used for a disease or microorganism that can be transmitted from one organism to the other organism through the environment. If we look at the two forms of Giardia, we find that out of the two forms viz. cysts and trophozoites, only the cysts of Giardia have the ability to remain alive in the environment outside the host and thus they are able to be transmitted to the other organisms. On the other hand trophozoites are not able to survive in outside environment so there is no chance of transmission of trophozoites.