An ecological niche can be define as the function that an organism play in an ecosystem. According to the principle of competitive exclusion if the two different species have the same ecological niche then the species which is more powerful and more competitive will be able to derive resources. The less competitive will deprive of resources and decline in number.
The human digestive system is made of gastroenteritis and organs such as saliva, tongue, and glands, etc. The digestion involves the breakdown of food substances into smaller components.
This begins in three phases. Chewing leads to the breakdown of food, saliva contains enzymes and the stomach consists of gastric glands.
Mitochondria are considered as the powerhouse of cell because they perform function cellular respiration process in a cell.
Cellular respiration is a process of converting the chemical energy present in nutrients into ATP which gives energy to organisms to carry out movement and physical actions.
Mitochondria performs cellular respiration process from which they can release energy present in food and nutrients.
Due to those reasons, mitochondria is called as powerhouse of cell.
The relationship between sunlight and chlorophyll is that chlorophyll absorbs sunlight and uses its energy to synthesise carbohydrates from CO2 and water.
These are both needed in photosynthesis because without sunlight and the chlorophyll, photosynthesis would not be able to synthesise carbohydrates from CO2.