Which best characterizes the precambrian era?
a. abundant plants and animalsb. dinosaursc. small, one-celled organisms and primitive jellyfishd. extensive mountain building?

Which of the following is an example of an environmental change the affected the evolution of life a. volcanic activity b. changes in climate c. mountain building d. all of the above

Aresearcher is studying the science of attractiveness and asks volunteer test subjects to rank what trait they find most attractive in a person what type of variable is the dependent variable in this experiment

How many chromosomes are in a gold fish?