Answer:
A. maintenance of axons is not a cellular activity associated with microtubules.
Explanation:
Microtubules are hollow, bead-like, tiny tubular structure that helps cells maintain its shapes. Together with microfilaments and intermediate filaments, they form part of the cell's cytoskeleton. Microtubules also contributes to the cell movement or cytokinesis that includes muscle contractions in muscle cells. Microtubules also replicated chromosomes to opposite ends of a cell during cell division. Microtubules also contribute to the parts of the cell that help it move and are structural elements of cilia, centrioles and flagella. A bundle of microtubules makes up an axonemal structure of cilia and flagella.
Answer:
When a ball accelerates toward bottom it experiences both rolling friction and air resistance.
Explanation:
- When the ball rolls from the hill the gravitational force of attraction comes in action and accelerates the ball toward the bottom of the hill.
- This motion of ball is the rotational motion, rolling friction acts on it due to rotational motion.
- As the velocity of the ball increases air resistance also starts to have significant effect on its motion.
- These two forces try to oppose the motion of the ball.
