The survival of any species depends on variation among its members. Which of the following prodcues the LEAST variation in a species?
A) asexual reproduction
B) gene mutations
C) recombination
D) sexual reproduction

Red blood cells are responsible for transporting oxygen in the blood. people with sickle cell anemia were born with a defective gene that results in sickle-shaped red blood cells. individuals with the disease often suffer pain in their extremities due to the build-up of these cells causing blockages in the blood vessels. the shape of the blood cells also reduces the amount of oxygen transported in the blood.