Question

Who gave chemical compositions of chlorophyll and carotenoids?
(a)Park and Baggins
(b)Meyer and French
(c)Willstatter and Stahl
(d)Arnon and Benson

Answer 1

Hint: They have given a widely accepted theory of leaf reflectance that has been investigated by extensive ray tracing through a model (W-S model) in which the leaf cellular structure is approximated by circular arcs.

Complete answer:
Willstatter and Stoll gave the chemical composition of the pigments chlorophyll and carotenoids in 1912. They discovered that chlorophyll has a tadpole-like configuration. It has a head called porphyrin and a tail made from long chain alcohol called phytol. Porphyrin heads are formed from four pyrrole rings which are linked by methine bridges. 5 atoms— 4 carbon and one nitrogen form the skeleton of each pyrrole ring. Nitrogen lies towards the centre.

Additional Information:
Chlorophyll and carotenoids are the sorts of photosynthetic pigments. Photosynthesis takes place within the green leaves of plants and other green parts of plants like stems etc. The ultimate energetic photosynthetic tissue in higher plants is the mesophyll of leaves. Mesophyll cells have many chloroplasts, which contain the specialized light absorbing pigments. These pigments are known as photosynthetic pigments.
Jean Senebier showed that carbon dioxide is consumed by plants during the assembly of oxygen. Mayer and Anderson were pioneers in plant physiology. Julius Robert Mayer was a German physician, chemist and physicist and one among the founders of thermodynamics.
So, the correct answer is 'Willstatter and Stahl'.

Note: Chloroplast contains chlorophyll pigment and carotenoids and performs photosynthesis. Carotenoids are divided into two classes: carotene and xanthophylls. Carotene is orange in colour and xanthophyll is yellow in colour. Chlorophyll is a pigment present altogether in green plants and a couple of other organisms. It is needed for photosynthesis, which is the procedure by which light energy is changed into chemical energy.