Select all that apply. hemoglobin a. picks up oxygen b. has an attraction for carbon monoxide c. has an iron ion d. is found in erythrocytes

Picks up oxygen, has an attraction for carbon monoxide, has an iron ion, and is found in erythrocytes.

All of them the above.

not necessarily. higher fitness requires the organism to be reproductive successful. for example, an organism at age 10 with 15 offspring is much more fit than an organism at age 15 with only 5 offspring.