Which of the following is an example of a closed system?
an estuary where fresh and ocean water mix
a chemical reaction within deep ocean organisms allowing them to glow
a living single-celled organism such as a phytoplankton
a river that flows into the ocean

Pink fur (p) is dominant to purple fur (p) in hamsters. two heterozygous pink hamsters are crossed. what is the probability that these two parents will have an offspring with purple fur? 2/4, 1/2 or 50% 1/4 or 25% 3/4 or 75% 4/4 or 100% there is no chance for this type of offspring

Ascientist is investigating the effects of salinity on fish development. he places fertilized fish eggs in an aquarium that contains low salinity and observes their development. what factor would improve experimental design the most? place the fish eggs in the open ocean because that is the natural habitat include another aquarium that has normal salinity to compare to the low salinity aquarium include an aquarium that replaces salt with sugar to confirm that the effects are specific to salt grow algae with the fish eggs in order to provide adequate nutrients to the developing embryos

3. in the fruit fly, recessive mutation brown, b, causes brown color of the eye and absence of red pigment. recessive mutation p of another independent gene causes purple color of the eye and absence of brown pigment. the cross of a brown-eyed female and purple-eyed male produced wild type eyes. what will be the colors and their ratio in f2?