The fruit fly cross shown here analyzes the transmission of two genes on the x chromosome. the male parent has mutant alleles for both the white gene (w-) and the crossveinless gene ( the female parent has nonmutant forms of these genes (w+ and cw+). a cross between siblings of the f1 generation—a red-eyed, crossveined female and a red-eyed, crossveined male—generates f2 progeny. examine the genotype of the f2 male progeny. notice that the progeny fall into two groups. refer to the figure below when answering the following question: the group that represents a small proportion of the progeny, deriving from maternal gametes containing combinations of alleles not found in either x chromosome of the mother, is called the .

Read the following scenario to answer the following question. 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. when most populations of a wide-ranging amphibian species are lost and the few remaining populations are widely separated, we expect to see that a. the founder effect becomes increasingly important b. microevolution no longer occurs c. gene flow between populations is reduced d. artificial selection becomes a greater factor in microevolution

Match the following terms describing electrical events with the correct phases of the cardiac cycle. the ventricular muscle cells depolarize at the start of this phase. during this phase, na+ entry through the funny channels causes the pacemaker potential of sa nodal cells to gradually become less negative until it reaches threshold. the ventricular muscle cells repolarize right before this phase. the cytosolic concentration of calcium in the contractile cells of the ventricle is highest during this phase. a. isovolumetric relaxation b. ventricular ejection c. isovolumetric contraction d. ventricular filling

What is the problem in this article? what solution does the article propose?