Answer:
Reproductive System
All the body systems have one role or the other to play in digestion and absorption. Even the excretory system removes waste and toxins from the body, leaving the useful materials.
However, the reproductive system is not actively involved in digestion.
The producers are the main source of the food production in the ecosystem. The producers are the organism, which convert the energy from the sunlight into the chemical energy. The consumers use this chemical energy for carrying out the metabolic processes in their body.
Without producers, the consumers cannot obtain their energy. Hence, the ecosystem without any producer would not survive.
The answer is apex and base. To simplify, the apex of the heart rests on the diaphragm and from its base, the great vessels emerge. In addition, blood vessels that are nearer to the pumping heart and must enlarge to endure pressure variations are named elastic arteries and foramen ovale permits blood to pass from the right to the left atrium, therefore avoiding to pass the fetal lungs.
