Which of the following has had the greatest effect on ozone depletion?
a. water vapor (h2o)
b. carbon dioxide (co2)
c. carbon monoxide (co)
d. chlorofluorocarbons (cfcs)

Which set of characteristics best describes sedimentary rock? a) largest type of rock, made of organic matter, hardest type of rock b) often contains layers, forms near sources of water, contains fossils c) least abundant type of rock, made of other rocks, made mostly of minerals d) most abundant type in earth's crust, made of magma/lava, contains no fossils

Ineed to get this test done which of the following statements is correct in hour our immune system responds to a potential pathogen? a.) the skin will be the first line of defense, and then the many phagocytes in the bloodstream will attempt to consume the possible pathogen. b.) b cells will start reading the antigen code immediately and call t cells to assist in destroying the pathogen. c.) the adapted immune system will call on the innate immune system to destroy the pathogen. d.) the t-cells in the adapted immune systems are the first to recognize the pathogen

What do we call an individual that has inherited two identical alleles for the same trait? a.homozygous b.heterozygous c.monozzygous