Question

Which protist groups have similarities in pigment composition?
A. Red algae and brown algae
B. Green algae and blue-green algae
C. Kelps and diatoms
D. Diatoms and euglenoids

Answer 1

Hint: The protists are plant-like unicellular organisms having pigments in them that perform photosynthesis. The chloroplast pigments give characteristic colors to the protists. The fucoxanthin gives a brown color to both large forms of algae and the planktonic alga.

Complete step by step answer: The Protists are single-celled organisms that come under the kingdom Protista. They include protozoan or simple alga species. They are neither plants nor animals. The characteristic property of algae is the presence of pigments that give them their characteristic colors.
Now let us see which of the given algae species share the same pigment showing the same color.
-Option A is red algae and brown algae. It is clear from the name that red algae are red due to the presence of chlorophyll A, phycocyanin, and phycoerythrin pigments. And brown algae are brown due to the presence of fucoxanthin pigment. Thus, this is incorrect.
-Option B is green algae and blue-green algae. Although the names are similar due to their characteristic colors, they both have different pigments. The green algae are composed of chlorophyll A and B that gives it the characteristic bright green color. The blue-green algae have chlorophyll and phycocyanin as their pigments. Thus, it is also incorrect.
-Option C is kelps and diatoms. These protists consist of chloroplast pigments named carotenoid and fucoxanthin. Both of these algae have a brown color. Thus they have similar pigment composition.
-Option D is Diatoms and euglenoids. As stated above the pigments in diatoms are carotenoid and fucoxanthin. The euglenoids are mostly green in color due to the presence of chlorophyll. Hence, they do not share the same pigment compositions.
Therefore, the right answer is option C.

Note: Pigments are chemicals that reflect visible light of a certain wavelength. Thus we can see alga in different colors due to these pigments like blue algae or blue-green algae, etc. Some of the pigments play an important role in photosynthesis in the alga. The common photosynthetic pigments are chlorophyll, carotenoids, and phycobilins.