Using what you learned about ecological interactions think of an example of each interaction in which humans are involved

a. Competition: Humans compete with all organisms for space.

b. Parasitism: Humans have many parasites: head lice, ticks, tapeworms, etc.

c. Mutualism: We have mutualistic relationships with all domesticated plants/animals.

d. Commensalism: Pigeons thrive in metropolitan ecosystems without really

affecting humans (except for being mildly disgusting).

an active site is a region that is present on an enzyme where the reactants or the substrate molecules we can say bind and experience a chemical reaction. the substrate is basically a reactant whose concentration is changing and that is converting into a product after binding at the active site of an enzyme

the oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. this blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. from the left ventricle, the blood passes through the aortic valve to the aorta.

deoxygenated blood leaves through the right ventricle through the pulmonary artery. from the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve), into the right ventricle.