Normal heart sounds are known as 'lub' and 'dub.' These sounds can be heart with a stethoscope as blood flows through the heart. According to the model of the heart sound cycle, what most likely causes the sound known as 'lub'? A) The 'lub' sound is caused as the atrioventricular valves close. B) The 'lub' sound is caused as the atrioventricular valves open. C) The 'lub' sound is caused as the semilunar valves close. D) The 'lub' sound is caused as the semilunar valves open

Select all the correct answers. which statements fail to meet the requirements of a scientific claim? 1 even though evidence indicates that the solar system's planets follow elliptical paths, copernicus's model involving circular orbits is true. 2 the evidence supporting newton's laws of motion was accurate in newton's time, but the universe operates differently today. 3 flowers that reflect the most ultraviolet light are more likely to attract bees and other pollinators than flowers that reflect less ultraviolet light. 4 in the final 100 meters of a 10,000-meter race, an athlete's speed is more strongly related to anaerobic efficiency than to aerobic efficiency.

Which of the following is a difference between active transport and facilitated diffusion? view available hint(s)which of the following is a difference between active transport and facilitated diffusion? facilitated diffusion can move solutes against a concentration gradient, and active transport cannot. active transport involves transport proteins, and facilitated diffusion does not. facilitated diffusion involves transport proteins, and active transport does not. active transport requires the expenditure of cellular energy, and facilitated diffusion does not.

Based on the law of dominance, we would expect percent of the offspring from this cross to have large teeth.