Answer:
400
Explanation:
Because if you pull one black marble out of four and there are 100 black marbles then there is 300 others, so in total it would be 400 marbles.
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Amphibia is the class of vertebrates which is considered to be the first to develop lungs. This allowed amphibians to live successfully on land as terrestrial organisms. Ichthyostega was the first primitive amphibians with nostrils and lungs. Amphibians adopted themselves to live on land with developed lungs.
Answer:
The correct answer is option d.
Explanation:
Chemical cycling illustrates the systems of concurrent circulation of elements between other states, compounds, and substances, and then return to their original state, which takes place in space, and on many objects in space comprising the Earth.
Chemical cycling of the nutrients (inorganic) is needed to maintain the conservation of nutrients on Earth. The chemical cycling of nutrients in a natural system requires a pool for the elements, the activities done by human beings, the biotic community and its food chains, and an exchange pool from which producers extract their nutrients. All the mentioned factors are associated with affecting a chemical cycling in exception to the input of geothermal energy.
Passive membrane processes are those that do not require energy and move substances down a concentration gradient; namely, these are diffusion, facilitated diffusion and osmosis.
