Answer:
Natural selection.
Explanation:
Imagine in the beginning there was a single species of bird. Naturally, this bird had to expand to the rest of the world, and was distanced as the continents drifted off. But this bird had to cope with various climates and environments. So the bird would gradually mutate over time. The bird in the jungles of central america would develop different colors and a shaped beak, and would better help it survive. This led to being the new normal for birds of this area. It would evolve to cover all the surviving birds in the region, until it is so drastically changed then it is a new species. There are so many different environments, each with its own challenges to overcome, so so many different bird evolve to survive them.
Answer:
Most animals obtain their nutrients by the consumption of other organisms. At the cellular level, the biological molecules necessary for animal function are amino acids, lipid molecules, nucleotides, and simple sugars. However, the food consumed consists of protein, fat, and complex carbohydrates.
Explanation:
We can get amino acids from eating food that contain proteins.
Proteins are made up of chains of amino acids. During digestion, the proteins are broken down into amino acids.
Explanation:
A negative feedback system has three basic components: a sensor, control center and an effector
