A human's breathing rate can be affected by

A. the level of carbon dioxide in the cells.

B. the level of oxygen in the blood.

C. the acidity of the blood.

D. all of the above.

Which of the following best describes similarities that exist between reptiles and amphibians? They are both ectothermic and have two-chambered hearts. They both have streamlined bodies and three-chambered hearts.

How would you explain to steno how fossil shark teeth could be found in the country side?

Based on the information in the graph, what conclusions can be drawn?

Movement of the diaphragm cause the air in and out to the lungs

What are isotopes and why are they important?

Compare and contrast photosynthesis and cellular respiration. you must write at least 1 similarity and 1 difference

Which of the following is the longest distance from Earth? A. the distance to the nearest star beyond the Sun B. the distance to the edge of the Universe C. the distance to the next galaxy D. the distance to the edge of our solar system

Which activity would eventually result in a stable ecosystem?

What cell structure would a leaf or a tree have that a fingernail wouldn't A. mitochondria B. Cilia C. chloroplasts D. ribosomes

Which phrase defines a law? a possible explanation or answer to a scientific question that is based on prior knowledge or research and is testable A statement of fact that is generally accepted to be true and universal because it has always been