How does genetic vatiation and enviromental factors contribute to evolution by natural selection and diversity of organisms?

4. how does a phospholipid behave in water? the phosphate head does not mix with water; the fatty acid tails do. the phosphate head and the fatty acid tails mix with water. the phosphate head and the fatty acid tails do not mix with water. the phosphate head mixes with water; the fatty acid tails do not.

How can scientists test their ideas about the origin of the universe if they can't physically interact with or study?

The idea of spontaneous generation was disproved by in a experiment involving jars of meat