Question

The red blood cells of birds differ from mammalian red blood cells because:

a) Birds have no red blood cells
b) Birds have nucleated red blood cells
c) Birds have smaller red blood cells
d) Birds have hemoglobin-free red blood cells

Answer 1

Bird red blood cells are nucleated, which differs from mammalian red blood cells that lack a nucleus upon reaching maturity. This structural difference impacts how each type carries hemoglobin and oxygen. Bird RBCs can also undergo mitosis due to the presence of their nuclei.

Step-by-step explanation:

The red blood cells (RBCs) of birds differ from those of mammals in several ways. The most notable difference is that bird red blood cells maintain their nuclei, while mammalian red blood cells lose their nuclei upon maturation. In mammals, this adaptation allows red blood cells to carry more hemoglobin, thus being more efficient at transporting oxygen to tissues. As red blood cells mature in human bone marrow, they lose their nuclei and organelles to maximize space for hemoglobin. However, bird RBCs, which are nucleated, can undergo mitosis, giving them a potential advantage in reparative processes.