What type of fish went extinct during the cretaceous period?

teleost

ichthyosaurs

both a and b

none of the above

Which scientific design has both practical limitations and limitations due to scale? studying the effect of bleach on the growth of mold spores exposing cultures of duckweed to different intensities of light observing the replication of dna molecules with a hand lens using colored marbles to model a cross between two colors of rabbits

All ova contain sex chromosomes corresponding to: x y xx xy

Why were the results whit just water so much different than the trials with the detergent ?