Which of the following would make the best index fossil? a. An insect that only existed in one small forest for abolit 100 million years
b. An aquatic animal that existed all over the world for about 15 million years
C. A single-celled organism that lived in a widespread region for about 25 million years
d. A plant species that lived in a specific geographic region for about 5 million years

I would go with B. Here’s why: An index fossil is usually easily recognizable, and underwent a wide geographic distribution. What leads me to believe B is the correct answer, is because it’s something that existed “ all over the world”.

the food storage products of chrysophytes are oils or the polysaccharide laminarin.   formerly classified as plants, the chrysophytes contain the photosynthetic pigments chlorophyll a and c all but the yellow-green algae also contain the carotenoid pigment fucoxanthin.