Final answer:
Normal erythrocytes are biconcave in shape and lack a nucleus and organelles, which provides more space for hemoglobin, the protein that transports oxygen and carbon dioxide.
Step-by-step explanation:
Normal erythrocytes, also known as red blood cells, have several key characteristics:
- biconcave shape - Erythrocytes are biconcave discs. This shape increases their surface area relative to their volume, which facilitates efficient gas exchange.
- lack of a nucleus and organelles - Mature erythrocytes do not contain a nucleus or other organelles such as mitochondria. This optimizes space within the cells for a higher concentration of hemoglobin, thereby maximizing their oxygen-carrying capacity.
- hemoglobin content - Erythrocytes contain a large amount of hemoglobin, a protein responsible for the transport of oxygen (O2) and carbon dioxide (CO2) in the blood.
Therefore, the correct options describing normal erythrocytes are that they:
- c. has a biconcave shape.
- d. contains hemoglobin to transport gases like O2.