Answer: Sea stars move using a water vascular system. Water comes into the system via the madreporite. It is then circulated from the stone canal to the ring canal and into the radial canals.
Explanation: The radial canals carry water to the ampullae and provide suction to the tube feet.
Answer:
The entry of food into the stomach.
Explanation:
Gastric secretion is triggered by the act of eating which is called as reflex phase and the entry of food into the stomach called a gastric phase. The entry of the food particles into the small intestine also helps to control the secretion of gastric called an intestinal phase.
The secreted fluid in the small intestine contains some ions, acids, etc such as pepsinogen, intrinsic factor, bicarbonate, hydrochloric acid, and mucus. The reflex phase or cephalic phase helps to stimulate parasympathetic neurons that release acetylcholine chemical, then it produces the higher secretion of gastric juice.
Answer: Van der Waals forces
Explanation:
Van der Waals forces are weak intermolecular forces that depend on the distance between two particles. They are caused by correlations in the change in polarization between two nearby particles. To put it in other words, when a particle changes its polarization (becomes more positive on one end and more negative on the other), so does the adjacent particle, and the next one, and so on. This causes these particles to stick together weakly.
The tiny "hairs" increase the surface area of the gecko's feet in contact with the wall, which makes the bond stronger and allows it to support all of its weight.
Because experiments have shown that geckos stick well to both hydrophobic and hydrophilic surfaces, we can assume there aren't any hydrogen bonds present.
Ionic bonds can't be present either because geckos wouldn't stick to electrically neutral surfaces, as these bonds require charged molecules.
I did this in my class a year ago and as far as i remember it was in the 1700 but i think 1767 to be exact
Answer:
There <u>warning calls</u> of other animals to scare them away from food.
Explanation:
Honest sentry to deceptive thief.
