A researcher wanted to determine the effect water temperature has on goldfish respirations. The researcher placed the goldfish in three different bowls of water with three different temperatures and counted the goldfish's respirations for two minutes in each setting.
What factors must be kept constant to obtain valid results ?
O length of time, size of tank, volume of water
O water temperature, length of time, volume of water
number of respirations, volume of water, the goldfish
the goldfish, size of tank, water temperature

One function of the poly-a tail on eukaryotic mrna sequences is to the mrna be transported from the nucleus to the cytoplasm. prokaryotic mrna also has a poly-a tail. choose the best explanation of the prokaryotic poly-a tail. a. prokaryotic poly-a tails are composed of a different molecular structure compared with eukaryotic poly-a tails. b. prokaryotic poly-a tails have the same functions as eukaryotic poly-a tails, because this process is highly conserved throughout different species. c. prokaryotic poly-a tails aren't important, because prokaryotes don't have nuclei. d. prokaryotic poly-a tails have other functions,because prokaryotes don't have nuclei.