The correct answer is option A, that is, placer deposits.
The concentration of heavy deposits known as the placer deposits are produced by the gravitational action, generally found in streams. The minerals that take place as placer deposits comprise copper, gold, magnetite, cassiterite, and copper.
The formation of placer deposits takes place when the metal-bearing rock on land is weathered and the generated debris is washed down to the sea by the rivers. Further by the action of waves, currents, and rides the particles of heavy metal gets amassed to produce mineral sand deposits. These generally occur as beach deposits.
Answer:
Plants are autotrophs because they can prepare their own food. Photosynthesis takes place in leaves. Leaves contain stomata that allow for the exchange of gases during the process, and also help with the process of transpiration.
Answer:
The entry of food into the stomach.
Explanation:
Gastric secretion is triggered by the act of eating which is called as reflex phase and the entry of food into the stomach called a gastric phase. The entry of the food particles into the small intestine also helps to control the secretion of gastric called an intestinal phase.
The secreted fluid in the small intestine contains some ions, acids, etc such as pepsinogen, intrinsic factor, bicarbonate, hydrochloric acid, and mucus. The reflex phase or cephalic phase helps to stimulate parasympathetic neurons that release acetylcholine chemical, then it produces the higher secretion of gastric juice.
Ecology
Ecology studies the life of living things and their environment.