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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magnetic force is appeared GUI
Answer:
C. It portrays evolutionary change as a smooth curve.
The abiotic environment consists of non-living things. So, rocks, temperature and water are part of the abiotic environment.
The correct answer is (a.) a mutation of the hemoglobin allowing better oxygen-carrying capacity. The mutation of the hemoglobin that allows a better oxygen-carrying capacity would be the most beneficial to an elephant and its descendants.
