Polymerization would be the answer you're looking for.
By all plants, algae, and some microorganisms
Answer:
The Mitral/Bicuspid Valve
Explanation:
The heart is composed of 4 chambers: left and right atria, and left and right ventricles. The “right heart” (right atrium and ventricle) receives deoxygenated blood from the systemic circulation through the Vena Cava, and impels this blood towards the lungs through the Pulmonary Arteries where it will be oxygenated. The “left heart” (left atrium and left ventricle) receives oxygenated blood from the pulmonary circulation through the Pulmonary veins and impels this blood towards the systemic circulation through the Aorta artery.
The systemic and pulmonary circuits work in series, and maintaining the unidirectional course of the blood flow is very important. This can be done by the presence of fibrous valves that are present between the atrium and the ventricles, and in between the ventricles and the Pulmonary/Aorta artery.
The location of these structures are as follows:
Systemic circulation ⇒ Right Atrium → [Tricuspid Valve] → Right Ventricle → [Pulmonary Valve] → Pulmonary Artery ⇒ Pulmonary circulation
Pulmonary circulation ⇒ Left Atrium → [Mitral/Bicuspid Valve] → Left Ventricle → [Aortic Valve] → Aorta ⇒ Systemic circulation
Each sieve tube element is normally associated with one or more nucleated companion cells, to which they are connected by plasnodesmata (channels between the cells). Each companion cell is derived from the same mother cell as its associated sieve tube member. Sieve tube members have no cell nucleus, ribosomes, or vacues. Thus, they depend on companion cells to provide proteins, ATP, and signalling molecules
The correct answer is: A. stimulates secretory activity
Parasympathetic nervous system is a part of the autonomic nervous system (a division of the peripheral nervous system (PNS), so it means it regulates unconscious actions in an organism. Parasympathetic system is known as a system for stimulation of "rest-and-digest", when the body is at rest (differ than sympathetic which is active for fight-or-flight response). Parasympathetic system works usually after the meal and it is involved in the functions such as, secretory activities (salivation, lacrimation ), urination, digestion and defecation..
