The correct answer is: A. minus end; dynein
Microtubules are cytoskeletal fibers that have an important role in the intracellular transport (movement of vesicles within the cell) and in the mitotic spindle during mitosis. The plus end of the microtubules extend through the periphery of the cells while the minus ends are anchored within the centrosome.
Necessary proteins for the vesicle’s movement are motor proteins:
• kinesin which is positive end directed
• dynein which is negative end directed
So, beside vesicles these proteins are also involved in organelles’ transport in opposite directions through the cytoplasm.
Unlike a bar magnet<span>, however, </span>Earth's magnetic field<span> changes over time because it is generated by a geodynamo (in </span>Earth's<span> case, the motion of molten iron alloys in its outer core).</span>
This change in chromosome number is the result of B. Fertilization. Both of the individual gametes from the male and female combine together to produce a zygote or developing offspring that is diploid in most cases, and possess both sets of genetic content or chromosomal information, one from each parent.