In gel electrophoresis why does the dna move toward the bottom of the wall of gel? a. dna is negatively charged. b. dna is positively charged. c. dna is extremely heavy. d. dna is less dense than air.

Over the past 60 years, many amphibian species have experienced significant population declines and some species have become extinct. scientists suspected that local human activities such as the destruction of wetlands, regional pollution, and deforestation were the main reasons for these losses. however, research over the past 20 years reveals significant amphibian population declines in protected areas of the world, such as nature preserves and parks. these global declines suggest widespread problems including increased ultraviolet radiation, acid rain, and disease. in switzerland, for example, 14 of the 20 native amphibian species are threatened with extinction. chytridiomycosis is a fungal disease first identified in 1998 as a cause of massive amphibian deaths. in some severely impacted populations, a few individuals have survived, perhaps because of some natural resistance. if these resistant individuals continue to survive and prosper, new resistant populations might emerge. this would be an example of the founder effect artificial selection genetic drift natural selection sexual selection

Briefly describe the scenario that was discussed in the behaving brain that demonstrated that the brain can change based on state or mood. which disease could the research involving rats and learning experiments that was discussed in the behaving brain ultimately with? in the behaving brain, what is a common misunderstanding about amnesia that was mentioned? what is the truth about amnesia that's mentioned? what does research discussed in the responsive brain show to be different in men and women's reaction to touch? what was discussed in the responsive brain as being brain-based and a vital part of normal growth and development in young children? in the responsive brain, what do they discuss as a possibility for leading to deficiencies in cognitive impairment as we age? in the responsive brain, what did the research involving african cichlid fish demonstrate? briefly describe the back story and affliction of the author of peter pan. what did you find most interesting about the behaving brain video, and why? what did you find most interesting about the responsive brain video, and w

The variation among individuals, on which natural selection acts