Answer:
The first and last box. If you don't agree with the first then definitely consider the last box.
Microtubules are macromolecules that build both, cilia and flagella.
<span>Microtubules are cytoskeletal fibres that are formed by polymerization of α,β-tubulin and they are important components of cilia, flagella and some other cellular structures. Cilia and flagella are very similar in their organization, both have a central bundle of microtubules-axoneme. Axoneme is compound of nine outer doublet microtubules which surround a central pair of singlet microtubules. Even thought cilia and flagella are structurally similar, they are differentiated based on their function and/or length. Flagella are longer and the primary role of the flagella is locomotion. On the other hand, shorten cilia often has the function in sensing the extracellular environment.</span>
Continuously facing towards the east also helps the flowers to heat up quickly. This gives them an advantage in pollination, as warm flowers attract insects. Therefore, in the plant's interest, the flower always faces the sun and is therefore always clearly visible to these important pollinators.
Answer: They evolved from the same line as the cave bear, descending from Ursus abstrusus, a small, primitive black bear. Ursus Euarctos, a black bear, came to North America during the Pliocene Epoch before the brown bear.
Substrate-Level Phosphorylation is a mode of ATP synthesis that occurs when an enzyme transfers a phosphate group from a substrate molecule to ADP.
This is from my AP Bio notes. Not 100% sure, but it does sound the closest in comparison to other processes.
