A community is where a group of people live really close by vs. a population counts how many people live in a area
You are right, it is B because, endocrine glands, as part of the endocrine system, they regulate and maintain a constant equilibrium in our bodies, known as homeostasis.
The Mitral valve which is also known as left atrioventricular prevents blood movement from left ventricle to left atrium.
Explanation:
- Human heart is four chambered.
- Two of these are receiving chambers known as atria and the other two are distributing chamber known as Ventricles.
- Atria are superior chambers and ventricles are inferior chambers.
- The heart has four valves broadly grouped as Atrioventricular valves and Semi lunar valves.
- Atrioventricular valves allows flow of blood from atria to ventricle. These are tricuspid valve and bicuspid valve.
- Semi-lunar valves allow blood to pass out of the heart. These include the pulmonary and aortic valves.
- The pulmonary valve allows blood to flow from right ventricle to the heart while aortic valve allows blood to flow from left ventricle to the Aorta.
- The Tricuspid valve located between the right atrium and right ventricle allows blood to flow from right atrium to the right ventricle.
- The Bicuspid valve ( Mitral valve) located between the left atrium and left ventricle allows the blood flow from left atria to left ventricle.
- Valves maintain the unidirectional flow of blood and thus prevent its back flow.
Passive transport<span> is a movement of </span>biochemicals<span> and other </span>atomic<span> or </span>molecular<span> substances across </span>cell membranes through <span>concentration gradients</span><span> without need of </span>energy<span> input. Unlike </span>active transport<span>, it does not require an input of cellular energy because it is instead driven by the tendency of the system to grow in </span>entropy<span>. The rate of passive transport depends on the </span>permeability<span> of the cell membrane, which, in turn, depends on the organization and characteristics of the membrane </span>lipids<span> and </span>proteins<span>. The four main kinds of passive transport are simple </span>diffusion<span>, </span>facilitated diffusion<span>, </span>filtration<span>, and </span>osmosis.
