Gregor Mendel developed the system of (blank) cross-breeding in the 1800s.

Amutagen is 1: a living thing that has undergone a mutation. 2: an agent that causes a mutation in dna. 3: a mutation that has affected one gene. 4: a chemical that can poison living cells.

Explain two reasons you think it is important for scientists to search for new ways to treat cancer

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