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.
Yististisutdhtsyisiysyjysz15:68047:86-4)yiztjsjtahro
X, right trigger, left trigger, left bumper, left, left, Y
A single-celled prokaryotic organism that is generally free-living and of few micrometers in length is bacteria. They are very small in size that cannot be seen without a microscope.
bacteria will be present in 100 milliliters of water.
<h3>How to calculate the number of bacteria?</h3>
Given,
- 1 milliliter = 1,500,000 bacteria
- 100 milliliter = ?
Therefore, option E is correct.
Learn more about bacteria here:
brainly.com/question/2490932
