Answer : Photosynthesis is an example of a chemical reaction.
Explanation :
Photosynthesis : It is a type of chemical process which takes place in the plant cell. In photosynthesis process, the light energy converted into the chemical energy.
As plant needs carbon dioxide, water and light. During the photosynthesis, carbon dioxide, water and sunlight react to gives glucose, oxygen and water as a product.
The balanced reaction of photosynthesis will be,

Hence, photosynthesis is an example of a chemical reaction.
The meter is the basic measurement unit for length. It has submultiples (centimeter, milimeter, micrometer) and multiples (kilometer).
100 cm = 1 m
1000 mm = 1 m
1000000 micrometers = 1 m
1000 m = 1 km
Explanation:
HIV is a decease that Is caused by sexual intercorse