Enzymes work to speed up chemical reactions in the body. what do enzymes actually do to speed up reactions? are the reactants and products changed by the enzymes?

Scientific method and data analysisa biology student wanted to determine if there is a relationship between resting heart rate and bodyheight. she gathered information from 12 classmates and constructed the table below. resting heart rate (beats per minute)student height (cm)155. 156156165180180190194195

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.

Environmental impacts on evolution : mastery test