Answer:
Active uptake (which I think you mean active transport) is important when the concentration gradient is against that of a certain substance, so it doesn't cross the membrane through diffusion or passive transport. It is sometimes necessary if a substance needs to move across a membrane but can't do so due to electrical charge or that there is a substance on the other side of the membrane preventing diffusion.
Explanation:
Either number 1 or number 3.
Bahahaha I don't even know.
sorry
Answer:
B) meteorite sample
Explanation:
The age of the solar system, derived from the study of meteorites (thought to be the oldest accessible material around) is near 5 billion years; that of the Earth is taken as 4.6 billion years. The oldest rocks on Earth are dated as 3.8 billion years.
<span>The group of snails would represent the "population" level of ecological organization. A single snail would represent and Individual. The snails and beetles would represent a community, and the garden itself with the various creatures would represent and ecosystem.</span>
Waves traveling through the inner core<span> go faster than those throughthe </span>outer core<span>.</span>
