Question

The absorption spectrum of chlorophyll
A. Approximates the action spectrum of photosynthesis
B. Shows that some colours of light are absorbed more than others
C. Explains why chlorophyll is a green pigment
D. All of the above are correct

Answer 1

Hint: Photosynthesis is a process which takes place in the presence of sunlight inside the thylakoid of chlorophyll. In this process, carbon dioxide and water are used as raw materials and glucose is produced and oxygen is released as a by-product.

Complete answer: Greens plants contain green pigment chlorophyll so they are green in colour. This chlorophyll absorbs red light and blue light. The red light has a long wavelength and the blue light has a short wavelength. This sets the absorption spectrum of the chlorophyll. The green light is not absorbed by the chlorophyll, instead, it reflects so that we can see the chlorophyll pigment green in colour. The absorption spectrum defines the wavelength of light that is absorbed by the leaf during photosynthesis. The similarity between the absorption spectrum of photosynthesis and chlorophyll defines that the chlorophyll is the most important pigment of photosynthesis. The spectrum is not totally identical due to the presence of carotenoids, which absorb blue light very strongly. Photosynthesis also occurs in organisms such as green algae.
So, the correct answer is option D.

Additional information: Photosynthesis involves two important phases; Light-dependent and light-independent phases. Light-dependent phases prepare energy, which is later utilized in light-independent reactions.

Note: There are three types of pigments seen in the plants – chlorophyll, anthocyanins and carotene. Chlorophyll is green in colour and results in the green colour of leaves, fruits. Anthocyanins are responsible for red colour and carotenes are responsible for developing yellow colour.