I believe the biggest space mission of the twenty-first century will be a manned mission to Mars, and the colonization that follows. This is the stated goal of several nations, companies, and individuals, all with considerably deep pockets. This mission will not only be a huge leap forward in space exploration, it will usher in a new era in human history in which the human race is an interplanetary civilization, a natural milestone as humanity continues to progress and advance.
Significant challenges are many and overwhelming. In terms of getting to mars, we need efficient, powerful propulsion systems and a spaceship that can not only accommodate a full crew for a mission that would likely last years, but withstand the various hazards that a long trip through space and entrance into the Martian atmosphere will entail. In terms of colonization, significant challenges will include establishing efficient and frequent travel/transport between the planets, and in the longer term, the necessity to terraform the planet (make it more like Earth) so that humans can more easily live there.
B. law of conservation of mass
This is why the total amount of and element before and after a chemical reaction is constant.
The answer is (D).. Stomata
Answer:
Homeostasis is defined as the state of body in which body maintains several chemical and physical changes inside the body affected by external factors.
Negative feedback loop includes a sensor, stimulus, control center, and effector which is used to control homeostasis.
A negative feedback loop is a reaction that reduce an excessive response and maintain the functions within the normal range. for example: if temperature and blood glucose level increases in the body, negative feedback loops control both the variables and maintain homeostasis.
Hence, negative feedback loops used to control body homeostasis.
