Answer:
A. ponds are shallower than lakes
E. lakes are colder and darker at the bottom than ponds
Answer: C. competition for nest sites between beetles and owls
Answer:
A person who receives a gene for sickle cell disease from one parent and a normal gene from the other has a condition called "sickle cell trait." Sickle cell trait produces no symptoms or problems for most people. Sickle cell disease can neither be contracted nor passed on to another person.
