Which of the following mutations is most likely to be passed on to future generations? A) cancer caused by excessive exposure of skin cells to the Sun
B) a chromosomal alteration that occurred during gametogenesis
С) breakage of a chloroplast in the leaf cell of a maple tree
D) damage to the mitochondria in a liver cell

Several billion years ago which gas was the least prevailant in the atmosphere

Ras is a g-protein that is activated when a growth factor attaches to egfr. its activation results in the replacement of a gdp molecule with a gtp molecule, thus allowing a signal transduction pathway to be activated. considering the signal pathway illustrated on this page, what is one potential outcome of a mutation in the ras gene that leads to ras protein hyperactivity. be specific.

Ihave no idea how to solve these. plus there's another question that is 2) a 10 kilogram meteorite is collected in space and brought back to earth. it is composed of 1.25 kg of uranium-238 and 8.75 kg of lead-206. how many u-238 half lives have passed? what is the approximate age of the meteorite?