There are lots of location that mechanical digestion occurs. But 2 common locations of mechanical breakdown of food (or physical digestion) occur in the mouth and in the duodenum.
Mechanical breakdown of food does not require enzymes, which is different from chemical digestion. Usually, the main function of mechanical digestion is to help speed up the chemical digestion later, usually by increasing the surface area of the food.
In the mouth, we chew the food. This can help increase the amount of surface area of the food we ate so that later on, the chemical digestion that requires enzymes such as amylase or protease will speed up. More enzymes can contact the food.
In duodenum, bile that are produced from the liver helps emulsify fats and lipids into small oil droplets. Again, this action can also help increase the surface area of the lipids so that the digestion of lipids with enzyme lipase would be more efficient. Note that bile is important because only enzyme lipase can digest lipids in the duodenum, so if bile is not produced, fats are hardly digested.
Other types of mechanical digestion may include the churning in stomach, or the squeezing of food in the oesophagus (peristalsis).
A sedimentary rock can become an igneous rock by melting and solidification.
Answer:
Light energy (sunlight)
By autotrophs
As they make food from it
Answer:
directional selection
Explanation:
Directional selection is the most common type of natural selection and occurs when some individuals with characteristics favorable to the conditions of the environment in which they live, have survival advantages over individuals who do not have this advantage, who end up dying.
Imagine, for example, a graph showing the directional selection in the same species of moths. Moths of the same species have white and brown collations, in summer, brown moths can camouflage themselves on tree trunks, while white moths cannot and are easily captured by their predators, which means that the amount of white moths decrease. In this graph, the population of white moths would be at a minimum, at the same time that the population of brown moths would be at maximum.
However, with the arrival of the reverse, snow begins to cover the trees, allowing white moths to camouflage themselves more easily. The brown moths, then, are very exposed to predators, causing their population to reach the minimum while the population of white moths reaches the maximum.
