Meiosis would be most beneficial to a species in a situation where an organism falls prey to many efficient predators. Answer:a)<span>Meiosis: numerous daughter cells produced would increase the species' population.
</span>The species needs to evolve quickly, and the best way to do that is to shuffle existing mutations through sexual reproduction.
The vertebrate endoskeleton is internal while an arthropod's exoskeleton is not
Answer:
True
Explanation:
Some deviations from normal homeostasis activate the positive feedback loops to control the conditions which are otherwise regulated by negative feedback mechanisms.
For example, the blood levels of respiratory gases and H+ ions are regulated by a negative feedback system via chemoreceptors. The increased partial pressure of carbon dioxide gas and lowered pH or lowered partial pressure of oxygen in the blood are sense by central and peripheral chemoreceptors which in turn activate the neurons of the dorsal respiratory group (DRG).
The activated DRG triggers an increased in the rate and depth of the breathing to facilitate the inhalation of more oxygen and exhalation of CO2 to restore the normal levels.
However, hypocapnia inactivates the chemoreceptors and does not allow negative feedback to restore the normal CO2 levels in the blood.
Under such conditions, the positive feedback loop stimulates the DRG neurons more strongly in response to the increased partial pressure of CO2 above the normal levels than when the partial pressure of oxygen falls below the normal level. These dangerously lowered oxygen levels may also cause fainting.
The odds are astronomical for a father with AB(IV) to have an O(I) child. The only possible way for this phenomenon to occur is if there was a nondisjunction in the ovogenesis for the 9th chromosome and the father also had a nondisjunction for the same chromosome(A sperm cell with no 9th chromosome fertilized an ovum with two 9 chromosomes).
A person with AB cannot donate to a person with O because the receiver has antibodies(alpha and beta) that bind to the antigens on the AB blood cells, causing death.
