Answer:
C
Explanation:
I would say C because it HAS to have valid data. Which is a limitation especially if you can't get that data.
<span>nerve cells need b 12 for proper functioning</span>
Answer:
Microtubules composed of tubulin protein.
Explanation:
The cytoskeleton is composed of three well defined filamentous structures: microtubules, microfilaments, and intermediate filaments. Each of these filamentous structures is a polymer of proteinic subunits united by weak, not covalent connections.
Microtubules are long hollo cylindric tubes with no ramifications of a diametre near to 25 nanometers. They are constituted by two subunits of tubulin protein which polymerize to form microtubules. These filaments shape the cell and are involved in intracellular transport. Microtubules extend from an organizing center near the nucleus to the cellular surface.
A. light energy, above the arrow
<span>Photosynthesis is a process wherein light energy is converted into chemical energy. </span>
Components of photosynthesis:
Water
Carbon Dioxide
Light energy, mostly from sunlight, is the main requirement for photosynthesis to occur.