Which of the following statements are considered to be normal? a. normal heart rates vary from 30 beats/minute up to 200 beats/minute. b. a heart rate less than or equal to 60 beats/minute is called bradycardia. c. a heart rate greater than or equal to 100 or 120 beats/minute is called tachycardia. d. a person’s heart rate will change depending on the needs of the body. e. b, c, and d are all correct.

How did the miller-urey experiment impact the way scientists think about the origins of life? use what you know about the miller-urey experiments to discuss the factors needed for life to arise, and speculate on whether life could arise on another planet.

Which of the following scenarios is an example of the bottleneck effect? answers a in south africa, much of the afrikaner population is descended from a small number of dutch colonists. in this population, this is an unusually high frequency of pseudoxanthoma elasticum (pxe), an elastic tissue disorder. b four white-tailed deer are introduced to a park in finland. thirty years after their introduction scientists compare the genes in the population and find that there is no variation. c during the industrial revolution, london's air became filled with soot. as a result, birds started eating more of the lighter moths because they were easier to spot than their darker counterparts. over time, the moth population changed so that there were more darker moths than lighter ones. d 10% of the population of american alligators in an area have the recessive trait albinism. a massive flood results in the death of 80% of the population. of the remaining population, 60% have the recessive trait of albinism.

Which of the following best describes the expensive tissue hypothesis? brains require more energy, so the gut had to be reduced, and larger brains and tool use led to higher quality diets. increasing body size means that homo neanderthalensis had to include more fat in its diet. brains require more energy, so the gut had to be reduced as brains got bigger. brains require more fat, so the gastrointestinal viscera (gut) had to expand, and hands were needed to acquire more food.