Answer:
lungs:
The blood first enters the right atrium.
The blood then flows through the tricuspid valve into the right ventricle.
When the heart beats, the ventricle pushes blood through the pulmonic valve into the pulmonary artery.
The pulmonary artery carries blood to the lungs where it “picks up” oxygen.
It then leaves the lungs to return to the heart through the pulmonary vein.
The blood enters the left atrium.
It drops through the mitral valve into the left ventricle.
The left ventricle then pumps blood through the aortic valve and into the aorta. The aorta is the artery that feeds the rest of the body through a system of blood vessels.
Blood returns to the heart from the body via two large blood vessels called the superior vena cava and the inferior vena cava. This blood carries little oxygen, as it is returning from the body where oxygen was used.
The vena cavas pump blood into the right atrium and the cycle begins all over again.
Isotonic solution. Hypotonic is less salt concentration and hypertonic is more
Answer: c. Part of an ecosystem
Explanation: the fish, crustaceans, molluscs and bacteria are part of a community, but sand is not. Each of those species is part of a population.
Answer:
Bilirubin.
Explanation:
Bilirubin may be defined as the yellow color pigment that occurs during the normal catabolic pathway of humans.This process in important for the removal of harmful waste products from the body.
Bilirubin is excreted in urine and bile. Jaundice causes the deposition of bilirubin that makes the body color yellow in the disease. The body's harmful waste are not eliminated due to the excess deposition of bilirubin in the body.
Thus, the answer is bilirubin.