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

Glucose, also called grape sugar, blood sugar or corn sugar, is among the simplest and one of the primary naturally occurring sugars. produced naturally by plants as the primary photosynthesis product, it is heavily used by living beings as a main energy source and is necessary for cellular respiration. chemically, it is a monosaccharide carbohydrate and serves as a building block for complex sugars like starch.