Answer:
Scientists are perhaps some of the smart few that make up the human population and are never short on knowledge. They research and discover and conduct tests to gain more knowledge, but the answer to your question is stars are huge celestial bodies made mostly of hydrogen and helium that produce light and heat from the churning nuclear forges inside their cores, and scientist know this because of their research.
Explanation:
Answer:
When the required direction of transport is opposed to concentration levels, a cell <u>will </u> expend energy to force<u> ions</u> across its membrane.
Explanation:
If the concentration gradient is opposite to the direction of transport of minerals, then the cell will use energy to transport mineral ions from a lower concentration to a higher concentration. The most common process through which this happens is termed as the active transport.
The process of active transport is opposite to passive transport. In passive transport, molecules move from a higher concentration to a lower concentration.
Muhammad Divided the first Islam empire
