The answer is a simple radial nervous system.
Echinoderms do not have brains. Around their mouth, they have central rings from which nerves radially run into arms and along the body. Movement is controlled by the branches of those radial nerves.
Lipid bilayer model was proposed for its structure but it was modified and new structure is according to fluid mosaic model. Plasma membrane is selectively permible as it selects small molecules like lipid etc (composition is also of lipid and as solubility principle like dissolve like) so large and charged molecules like plasma and ion can't pass through it. Lipid are in form of layer so at the chain when ever other phosphate group attach the place conjugate molecule (phospholipid ) formed
Mass is the amount of matter in an object. Move to a different planet and an object's weight will change, but its mass will be the same. There are a couple of ways to measure mass. The most common method is to use a balance.
- Balances and Scales.
- Space Linear Acceleration Mass
- Measurement Device
- Measurement Transducer
- Vibrating Tube Mass Sensor
- Gravitational Interaction
Biome, though some might say ecosystem instead. Biomes are very large ecosystems that cover broad areas.<span>If they specify "one" reef, then they are probably looking for "ecosystem"</span>
If the temperature is too low, enzyme molecules don’t have enough kinetic energy to collide and combine with other substrate molecules. So the enzyme activity/ reaction rate will be very low. The rate will rise again once the temperature increases to its optimum temperature.
But if the temperature is too high, enzyme will be denatured, which means the shape of the active site of the enzyme is changed. It can no long combine with other substrate molecules. The rate will drop significantly. Yet, lowering the temperature won’t help because denaturation is permanent and irreversible.