During which phase of meiosis do homologous chromosomes exchange segments?

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

What must be done to breed dogs for a partical trait

9. the history of life on earth is recorded in