How are red blood cells able to move through narrow vessels to carry oxygen throughout a multicellular organism?
They are small because their organelles are smaller than those of other cells.
They are flexible because they lack a plasma membrane.
They are small because they lack a nucleus.
They are long and thin with a tail-like end.
The correct answer is: They are flexible because they lack a plasma membrane.
Red blood cells, also known as erythrocytes, are able to move through narrow vessels due to their unique structure. They are small and flexible, allowing them to squeeze through narrow capillaries and navigate through the circulatory system. Unlike other cells, red blood cells do not have a nucleus or other membrane-bound organelles, which further contributes to their ability to traverse through narrow conditions.
Red blood cells are able to move through narrow vessels to carry oxygen throughout a multicellular organism due to their specific characteristics. These include:
1. Small size: Red blood cells are small in size compared to other cells in the body. This is because they lack a nucleus, which allows for the maximization of their oxygen-carrying capacity. The absence of a nucleus also helps in making them smaller and more flexible.
2. Flexibility: Red blood cells are highly flexible due to their unique structure. They contain a specialized protein called spectrin, which forms a mesh-like network and provides the cell with its flexibility. This enables red blood cells to squeeze through narrow capillaries and navigate the twists and turns of the circulatory system.
3. Lack of organelles and plasma membrane: Mature red blood cells lack most organelles, including the nucleus, mitochondria, and endoplasmic reticulum. This lack of organelles allows the red blood cells to have more space for hemoglobin, the protein responsible for carrying oxygen. Additionally, the absence of a plasma membrane reduces their overall surface area, allowing them to flow more smoothly through narrow vessels.
Therefore, the correct answer is: They are small because they lack a nucleus.