I think it's important to concentrate yourself to complete what you are doing, but if you have also new ideas try to develop them into something useful
Leeches are parasitic because they suck blood not giving any benifit but harm.
Answer:
Echinoderms use its tube feet for "<u>movement, respiration and taking food".</u>
Explanation:
Tube Feet are tiny tube like projections on oral side of echinoderms. They use it for movement, food and respiration. Echinoderms also use them to stick the ocean floor and move at a leisurely pace.
Four general conditions necessary for natural selection to occur<span> are: A. More organisms are born than can survive. B. Organisms vary in their characteristics, even within a species. D. Differences in reproduction and survival are due to variation among organisms.</span>
Answer:
Please see below
Explanation:
The original primates' key adaptations to their arboreal life way included binocular vision to judge depth and be able to jump to the next brach without falling to a certain death; an opposable thumb, to be able to hold to a branch with a secure grip, and arms longer than legs to swing from branch to branch. This forced them to walk on all fours but it wasn't disadvantageous because they went down to the floor for short periods. During their transformation to humans which resulted from their invading a new habitat in the more open grassy savannas, the opposable thumbs allowed them to use tools, like rocks and sticks which they could use to get food and defend against their enemies. They had to walk upright on two legs, to be able to see afar and locate potential food or predators, so natural selection eventually resulted in longer legs and a modification in the backbone. The significance of this evolutionary history is that modern humans are what they are as a result of a combination of preadaptations from their arboreal ancestors and the new features that resulted from their new habitat on the open ground of the savanna.
