An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there by human activity, directly or indirectly, and either deliberately
Answer:
A(the first one)
Explanation:
Homeostasis maintains the constant internal conditions in an organism. It is important because cells function best with a limited range of conditions. ... All living things have body parts with different functions that help them survive.
Hmm good question. Well I would have to test it for where there are no living life. I would have to build another NASA in the County because there is plenty of room there. Mars is made out of Dusty Crust that is about 30 miles thick. And let's say that the desert's Dusty Crust is about 5 miles - 15 miles thick. That will give about the same amount of surface that mars has. So we would know what to build for a perfect lander to work on Mars. This isn't much but it is something.
Answer:
We have just seen that pathogens constitute a diverse set of agents. There are correspondingly diverse ranges of mechanisms by which pathogens cause disease. But the survival and success of all pathogens require that they colonize the host, reach an appropriate niche, avoid host defenses, replicate, and exit the infected host to spread to an uninfected one. In this section, we examine the common strategies that are used by many pathogens to accomplish these tasks.
Explanation:
The first step in infection is for the pathogen to colonize the host. Most parts of the human body are well-protected from the environment by a thick and fairly tough covering of skin. The protective boundaries in some other human tissues (eyes, nasal passages and respiratory tract, mouth and digestive tract, urinary tract, and female genital tract) are less robust. For example, in the lungs and small intestine where oxygen and nutrients, respectively, are absorbed from the environment, the barrier is just a single monolayer of epithelial cells.
Skin and many other barrier epithelial surfaces are usually densely populated by normal flora. Some bacterial and fungal pathogens also colonize these surfaces and attempt to outcompete the normal flora, but most of them (as well as all viruses) avoid such competition by crossing these barriers to gain access to unoccupied niches within the host.
