There is only species of a koala but you can ask how many races there are.
The name is, "phascolarctos cinereus".<span />
The correct answer is: A checkpoint will be activated if the spindle does not attach to a kinetochore.
Prokaryotes, do not undergo mitosis (like eukaryotes) and therefore have no need for a mitotic spindle. Prokaryotes also don’ t have checkpoints foor the regulation of cell division.
Normal eukaryotic cells (unlike cancer cells), move through the cell cycle in a regulated way in order to make sure that cells don't divide under conditions that are unfavorable for them. Information about their own internal state (nutrients, signal molecules, DNA integrity) is signal to go or not to go through the cell division. Because of that there are few checkpoints in the cell cycle at which the cell examines the signals and makes a “decision”. The major checkpoints are:
• The G1- the first point at which it must choose, once it passes the G1 checkpoint the cell enters S phase
• The G2-the cell checks DNA integrity and checks if replication is done well.
• The spindle checkpoint-at the transition from metaphase to anaphase.
Hypophyseal portal system is a blood system of vessels in the microcirculation at the base of the brain, connecting the hypothalamus with the anterior pituitary. It is involved in quick transportation and exchange of hormones between the hypothalamus arcuate nucleus and the anterior pituitary gland. Hypothalamic-hypophyseal tract comprises of neurons that deliver vesicles with neurohormones from the hypothalamus to the posterior lobe of the pituitary gland. In this case, it is partly contained within the infundibulum (hollow stalk connecting the hypothalamus and the posterior pituitary gland).
The answer would be flock