Answer:
uhh either natural and reproductive pretty sure it's reproductive
1. electrical signals travel toward the heart. 2. signal received by the atrioventricular node. 3.signal by the nodes in the atrium. 4.the atria contracts. 5. signal transferred to the ventricles. 6. the ventricles contract.
The answer is T-cells.
T-cells (T-lymphocytes) have a central place in cell-mediated immunity. On the surface of T-cells, T-cell receptor is present. When T-cell binds to the antigen via antigen receptor, the recognition occurs. Therefore, T cells act as a bridge between the cellular and humoral (antigen) response.
Answer:
Below
Explanation:
They are important because they can help up get warmer/colder when our bodies can't
