Sam came home from school with a cold caused by a virus and his sister, ana, caught it from him. sam got well and went back to school. a few days before ana got well, sam came down with a cold again. their mother said that ana had given the cold back to sam. how likely is it that their mother is correct, and what does it mean for ana's chances of getting sick again?

Where do homologous chromosomes exchange genetic material through crossing over?               a.  chlorophyll    b.  centrosomes    c.  centromeres    d.  chiasma

This map shows how climate change might affect precipitation patterns in the great plains of the united states by the end of this century. brown shoes a decrease in percipitation, and blue shows an increase. the maps differ based on the predictive levels of green house emissions. the maps shows that northern area should get a. more pracipations regardless of emmissions b. less pracipation, regardless of emmissions levels c. more precipitation, but only when emission levels.southern areas show a. more pracipations regardless of emmissions b. less pracipation, regardless of emmissions levels c. more precipitation, but only when emission levels.to use these maps to prepare for natural disasters in the great plains, scientist need to ask? a. how many tons of emissions were used at the basis of the map.b. which types of fossil fuels are used in the great plains c. if you think the above is wrong it's probly c the question is cut off

Approximately what wavelength of light is best absorbed by chlorophyll a