Biology Help Please! Evolution & Animals.?

Question

1. HOW & WHERE does gas exchange take place in Sponges, Cnidarians, & Flatworms?

2. What is one advantage of an animal having bilateral symmetry?

3. How does antibiotics resistance support the theory of natural selection?

4.Why doesn't the process of natural selection produce more perfect adaptations than it does?

5. Although a religious controversy with the evolutionary theory exists today, give an argument for why such a controversy is Invalid.
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1. I'm still searching for the other 2 but I believe Flatworms= Gas exchange occurs across their body wall & there is Diffusion of O2 into the body & CO2 diffuses out.

2. Idk but I read something about it helps reproduction? I can't really find any Real info on it and my book isn't helping.

3-5. ?
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I would really appreciate any help and explanations. Thank You! = )

Answer 1

1. Everywhere the sea water touches.
2. Symmetry allows for the streamlining needed for swimming?
3. Since bacterial populations are experiencing change in allele frequency due to selection by antibiotics, they are evolving by definition.
4. Every organism "plays the hand it was dealt." Natural selection weeds out the unfit and unlucky. The goal is not "perfect offspring," but "more offspring than average."
5. This refers to the idea that public schools should "teach the controversy." Unfortunately, the controversy rests on the fact that some religious nutjobs feel it is their job to protect God from destruction from Darwin's idea.

Answer 2

1. The animals in these groups exchange gases by diffusion - directly from the environment. No special respiratory structures.
2. Bilateral symmetry gives organisms a head end and a tail end with most of the sensory structures concentrated in the head end.
3. Each bacterium either CAN or CANNOT survive exposure to the antibiotic. The ones that survive will reproduce more generations that can also survive the antibiotic. This is evidence for natural selection.
4. Natural selection works on chance variations in individuals. The variations have happened accidentally, not by plan, so nature can only choose the best variation from those that have happened. It's not as if nature gets an idea and then designs something to match the idea.
5. Religion is based on faith. By definition, faith means a belief in something without relying on actual evidence. Evolution has to do with science, and science only supports ideas that have evidence. Faith and science are two different things.

Answer 3

1) they do not have or need circulatory systems, as all their cells are close enough to get oxygen directly from the environment via osmosis

2) two identical sides helps to provide back-ups, for example kidneys... if one fails, the other can take the full job.

3) Natural selection is "survival of the fittest" aka, if antibiotics kills off all but the strongest bacteria, the stronger "resistant" bacteria are selected for, and thrive.

4) Because of two reasons: 1) mutations are random and 2) most mutations are only slight deviations of what was already there... aka, you can only work with what you've got! Birds didn't just decide they wanted to fly one day and evolve wings.

5) Religious theory of creationism is not based on the scientific process, it cannot be tested. It cannot be disproved. Adaptive mutation (which can be extrapolated into the theory of evolution) is a testable and valid scientific fact.

Answer 4

Sorry, I made it through high school already and did all the homework I needed to do.