1. Trachea itself is not considered a complete organ. It is a part of the breathing system and the only airway to the lungs.
2.Yes rigid organs.
3. Rigid organs constitute part of the endoskeleton of vertebrates.
Acetylcholine is the neurotransmitter important for muscle contraction as it binds to receptors on the membranes of muscles and cause the membranes to open channels for movement of calcium and sodium ions
Blood Type A and Blood Type B are co-dominant traits. They do not dominate each other, rather they combine to form blood group AB. This is only possible if both the blood groups are pure.
Answer:
A biologia abrange diversos campos, incluindo botânica, conservação, ecologia, evolução, genética, biologia marinha, medicina, microbiologia, biologia molecular, fisiologia e zoologia.
Explanation: