This was Lamarck's idea. Here's an example: Suppose giraffes originally had short necks that they stretched to reach high-up leaves in the trees. This continuous stretching of the neck was passed onto offspring, who as a result had slightly longer necks. This continued for multiple generations until we get today's long-necked giraffe. Lamarck was on to something (that something being evolution by natural selection, which Darwin discovered), but his theory wasn't completely correct since organisms can only pass on genes (segments of DNA that code for a characteristic or function) to their offspring. Since "stretching" would not code into DNA, it wouldn't be passed onto offspring, proving Lamarck's theory incorrect.
A placebo is kind of a "fake" treatment but, typically the person receiving a placebo is unaware it has no medical effect on them so they believe they are feeling better. For example, a lot of anxiety meds are placebos and people don't know so their brain tricks them into thinking they are feeling less anxious. This could be used in experiments where a group believes they are affected to see how they react
The answer I believe is diversity or evolution, survival of the fittest
The tip of a chromosome is called a telomere
Answer:
oxygen gas is most abundant in the atmosphere