Octopus and squid have little suction cups on their tentacles. It helps with sticking onto food (so it doesn't get away) and also helps with sticking into things. If it wanted to camouflage into some rocks, it can use its tentacles to cling to to the rock.
Tentacles can also grab and carry things. Scientists have made tests where they would put a clam in a jar with the lid screwed on. The octopus would grab onto the jar and use its tentacles to twist the lid off.
Without tentacles, octopuses and squids would be pretty helpless and probably couldn't survive in the deep ocean.
The answer is false, liquid molecules continue to move even after the concentration is uniform.
Diffusion happens because there’s a concentration gradient between the dye and the water, therefore dye molecules moves to the water area. But note that this is only the net movement of the molecules, which means, even if more molecules are moving towards water, there are still some dye molecules that are moving in the opposite direction.
So, after the concentration is equal, the motion of the dye molecules does not stop, they still move in random directions, but there’s no net movement instead, as there’s no concentration gradient. Remember molecules are always moving in all directions , it just depends on whether there’s a net movement or not. If there’s no net movement, the amount of molecules moving to each and every direction is always equal.
Natural selection refers to the phenomenon by which the species in a population possessing the tendency to get adapted in a condition enhance in numbers in comparison to those who exhibit fewer adaptation capacities over a number of generations.
In other words, it can be stated as the non-random and differential development of distinct genotypes function to sustain favorable variant and to eradicate less favorable variants. Some of the conditions are required for the process of natural selection to take place.
These are heredity, reproduction, variation in individual characters, and variation in the fitness of organisms among the members of the population. If the conditions are met, then the phenomenon of natural selection occurs by default.