Answer:
The correct answer is A. a rotating cloud of dust and gas.
Explanation:
Nebulae are regions of the interstellar medium (clouds) made up of gases (mainly hydrogen and helium) and dust. In other words, nebulae are concentrations of gas in which we find hydrogen, helium and stardust in greater quantities. They are structures that are actually very important for the universe, this because inside it is the place where stars are born, which arise due to the condensation and aggregation of matter. The nebular theory states that the Solar System reached the form current from a solar nebula (a gas cloud), more than 4.5 billion years ago. The large cloud of molecular gas was affected by a certain phenomenon that would have taken place in the vicinity. Like the explosion of a supernova or the passage of a star that would produce a strong gravitational impact. The result of this event made the matter agglomerate in different places. The high concentration of matter caused the nebula to collapse. Becoming a protostar, (bodies whose characteristic is to be surrounded by clouds and contain preplanetary matter inside), that is, gaseous matter in the outermost part and solid inward. At the core of this structure, the temperature is so dominant that nuclear reactions take place to compensate for the gravitational force. This leads to a hydrostatic equilibrium and the formation of a fundamental star: the Sun. The rest of the mass flattened, forming a protoplanetary disk where the protoplanets were being formed, which would evolve to become the current planets, their satellites and the others bodies of the solar system.
Most developing countries have abundant renewable energy resources, including solar energy, wind power, geothermal energy, and biomass, as well as the ability to manufacture the relatively labor-intensive systems that harness these.
Plasma is blood minus the corpuscles. Components of plasma include;
Respiratory gases (oxygen and carbon dioxide)
Nutrients (glucose, amino acids and vitamins)
Proteins (such as albumins and other carrier proteins)
Hormones (such as steroid hormones)
Antibodies and clotting factors
Waste products such as urea
Answer:
<u>Passive</u> transport
Explanation:
There are two ways molecules can get in and out of the cell. These processes are called Passive and Active transport.
Passive transport is the movement of molecules and materials from high to low concentration. No energy is needed for this process because it happens naturally.
This is in contrast to what Active transport is, where energy is needed because it moves the molecules or materials against the concentration gradient where they move from lower to higher concentration.
