Answer:
c. Tubulin
Explanation:
Tubulin protein is polymerized to form the cylindrical structures of microtubules. Microtubules form the spindle apparatus during cell division. The spindle microtubules become attached to the kinetochores of chromosomes and mediate the alignment of chromosomes at the equator of cells during metaphase. The shortening of spindle microtubules is responsible for the movement of sister chromatids during anaphase. The same event also moves the homologous chromosomes during anaphase-I.
Any failure in the formation of the spindle apparatus would not allow the proper separation of chromosomes. Therefore, the cell with abnormal chromosome separation might have a faulty or no tubulin.
Answer:
Closely related species occupying the same niche.
Explanation:
Competitive exclusion principle states that the two species cannot exist together if they share the same resources. The one species completely exclude the other species from their niche.
Competitive exclusion principle generally occurs between the species that occupy the same niche and are closely related with each other. The competitive exclusion principle first explained between the species <em>P. aurelia </em>and <em>P. caudatum.</em>
Thus, the correct answer is option (B).
No. The answer is C, 1/4.
Protons: positive
neutrons: no charge
electrons: negative