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:
You didn't give any answer choices (i'm answering this through research and what i already know)
the first is fossilized dung, and that's not generally gastropod shells. A carbon film would be something thin, seeing as it's a film, and gastropods aren't that. A gastrolith is a stone swallowed by an animal to help with digestion, and that's also not a gastropod.
<span>Gastropod fossils may be molds, but usually aren't. Still, they can be. It's a better answer than; film or stomach stones.</span>
The answer would be B) Nitrogen Trioxide
Answer:
through years of evolution as natural selection shaped animal adaptations to Earth's environments.
Explanation:
Over the years, biologists have been able to successfully name more than one (1) million animal species across the world. These species arose through years of evolution as natural selection shaped animal adaptations to Earth's environments.
Natural selection can be defined as a biological process in which species of living organisms having certain traits that enable them to adapt to environmental factors such as predators, competition for food, climate change, sex mates, etc., tend to survive and reproduce, as well as passing on their genes to subsequent generations.
Simply stated, natural selection entails the survival of the fittest. Therefore, the species that are able to adapt to the environment will increase in number while the ones who can't adapt will die and go into extinction.
