The goal was to orbit a spacecraft around the Earth. It has people in it. So the answer is B.
Answer:
Cytoskeletal elements play important roles in cell division. The mitotic spindle apparatus is made of "microtubules" and pulls sister chromatids apart, whereas the contractile ring is made of "actin filaments" and required for the separation of daughter cells at the end of the mitotic phase of the cell cycle.
Explanation:
The three chief organizational apparatuses of the cytoskeleton are microtubules (formed by tubulins), microfilaments (formed by actins) and intermediate filaments. All three apparatuses cooperate with each other non-covalently. The cytoskeleton is composed of protein filaments and is found throughout the inside of a eukaryotic cell. The cytosol is the main component of the cytoplasm, the fluid that fills the inside of the cell. The cytoplasm is everything in the cell except for the cytoskeleton and membrane-bound organelles.
