An ecologist wanted to know how many plants lived in a particular prairie. Instead of counting all the plants, the ecologist used a sample area. The ecologist placed a grid that was ten meters by ten meters in a random location in the prairie and counted the number of individual plants of the various species. Data were collected and recorded. Answer these:

Describe an observation from the prairie sample study.

Describe an inference from the prairie sample study.

Describe a difference between any observations and any inference

the answer is trees if i'm not mistaken

weathering is the answer.

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.