Correct Question and options:
Only red algae can grow in relatively deep regions of the ocean because red algae are:
a. capable of absorbing carbon dioxide even from the carbon dioxide deep waters and using the carbon dioxide to build sugars during photosynthesis.
b. specialized for absorbing longer wavelengths of light that penetrate deeper into the water for photosynthesis.
c. able to perform chemosynthesis, rather than photosynthesis.
d. capable of absorbing ultraviolet light for photosynthesis, rather than visible light.
Answer:
The correct answer is b. "specialized for absorbing longer wavelengths of light that penetrate deeper into the water for photosynthesis".
Step-by-step explanation:
Red algae, also known as Rodophytes, are immobile organisms that inhabit the sea, but might also be found in freshwater and some of them can even be terrestrial. Due to its pigments, this algae is capable of absorbing sunlight in great depths, even much more than other types of algae. Rodophytes are photosynthetic organisms, which means that when they absorb sunlight they can transform it into energy.
Red algae´s coloration is due to the rhodoplasts that contain chlorophyll a, in addition to other pigments such as phycoerythrin and phycocyanin, that are phycobiliproteins. These last ones mask the chlorophyll and make a place to the characteristic algae´s red color.
Only red algae can grow in relatively deep-sea regions because they are specialized in photosynthesizing by absorbing longer light wavelengths that penetrate deeper into the water. Phycoerythrin is the one that absorbs the green wavelengths that reach deep regions and emits the red wavelengths of light. These proteins capture light energy and transfer it to chlorophylls during photosynthesis.