Answer:
The three-chambered hearts of amphibians and nonbird reptiles are facultative, allowing variation in blood flow through the heart.
Explanation:
In Anatomy, cardiac cycle can be defined as a complete heartbeat of the human heart which comprises of sequential alternating contraction and relaxation of the atria and ventricles, therefore causing blood to flow unidirectionally (one direction) throughout the human body.
Generally, the cardiac cycle occurs in two (2) stages;
I. Diastole : in this stage, the ventricles is relaxed and would be filled with blood.
II. Systole: at this stage, the muscles contracts and thus, allow blood to be pushed through the atria.
All amphibians and reptiles except for crocodiles (having four-chambered heart) have three-chambered hearts, which typically comprises of a partially divided ventricle and two atria.
Hence, the correct statement about the three-chambered hearts of amphibians and nonbird reptiles is that, the three-chambered hearts of amphibians and nonbird reptiles are facultative, allowing variation in blood flow through the heart due to the partially divided ventricle.
<span>C. gizzard. hope his helps
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Answer:
disturbance has destroyed population in a community
Explanation:
The secondary succession occurs after there has been some disturbance that has manged to badly damage or destroy the populations in a community. This basically means that after some catastrophic event that happened to a certain population or populations, other species moved in to colonize the freed space. There are countless examples of secondary succession in nature, and one of the best is when there is a strong volcanic eruption. The volcano manages to destroy the population of plants and animals in its close surroundings, but after the eruption ends, the space starts to be colonized by new plants and animals step by step until they create a new well functioning community.
