Answer: Higher concentration; Lower concentration.
Explanation: The food that we eat undergoes digestion and breaks down into smaller components.
These small components of the food needs to be absorbed first by the process of diffusion.
The water molecules along with the electrolytes are absorbed from an area of its higher concentration in the lumen is transported to area where its concentration is very low.
Hence, the correct answer is diffusion, which is responsible for the transportation of products from one place (higher concentration) to another parts (lower concentration)in the body.
The fossil record shows a sequence from simple bacteria to more complicated organisms through time, it is very reliable because it is physical evidence and by studying fossils, scientists can learn how much (or how little) organisms have changed as life developed on Earth.
<span>This would be an example of a mutation, because the changing of allele frequencies would be a change within the gene itself, which would be a mutation in the DNA. This is evidenced by the fact that there is now a form of human resistance to malaria, due to changes within human DNA itself.</span>
Answer: Natural selection is one of the forces of evolution and the enviroment where the species lives is the selection agent. For example, suppose a mosquitoes population in a environment free from insecticides, in this environment there's a high frequency of non-resistant mosquitoes because the environment is not exerting any pressure on the resistence trait. But when the environment changes and we use a insecticide upon the mosquitoes population, the populations changes because the non-resistant ones die but those resistant survive and beggin to reproduce more effectively. That's natural selection, differences in survival and reproduction between individuals with different phenotypes (traits) and this differences depend of environmental changes.
