iron and polar molecules
A buffeer is a solution that can resist pH of an acid or basic components.
<span>Helium has an atomic number of two, so its outer energy level is full. Helium is considered INERT.
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The four limitations are
1.It's often impossible to repeat trials on the same subjects.
2-Subjects may report an inaccurate medical history.
3-It can be difficult to control all possible variables.
4-It's impossible to come up with testable scientific questions for human subjects.
Research involving human beings is ultimately necessary for improvements in human health and welfare. Any results about healthy physiology, illness causes, treatment effectiveness, learning, or behavior must be verified by carefully controlled investigations involving human participants. Sadly, not all human research have been valid and beneficial. It is possible to harm people in the name of research. The most well-known instances happened in Nazi Germany. Investigations conducted after the war found several crimes, including experiments in which participants were submerged in extremely cold water to determine how long it would take them to pass away from hypothermia.
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Explanation:
the name porifera means pore bearer in latin. a sponges body is covered by a skin, one cell thick. this skin has lots of small pores ad a few large openings. the small openings are the entrances to a complex system of channels. these collar cells pump water through the entire sponge and filter out food for the sponge cell to eat
230 is your anwser! sorry bad english
