Which gas in Earth’s atmosphere has increased over time due to burning fossil fuels?
oxygen
nitrogen
water vapor
carbon dioxide

Isolated volcanic peaks on the ocean floor are

In guinea pigs, black fur (b) is dominant over white fur (b). cross a heterozygous (hybrid) black guinea pig with a homozygous (purebred) white guinea pig. complete a punnett square, identify the genotype(s), phenotype(s), and probability (% and fraction) that the offspring will be black and white?

Which muscle cell structure stores calcium ions that are used to trigger the contraction?