The answer here is D, and it's kind of obvious. But you probably already knew the answer and are just doing this for piece of mind.
Explanation: Just the fact that we don't know whether or not there even is extraterrestrial life rules out every other answer, without even needing to go in depth.
(Okay, I read your question completely wrong, it's asking for which one of these has been solved isn't it?)
This is tough because all of these other than D have been figured out. Go with the methane atmosphere then.
The decrease of testosterone in males is called andropause. This happens when a man reaches the age of 40 where there is a gradual decrease in their testosterone; about one percent less each year. Symptoms of andropause include, depression, insomnia, increased body fat, and difficulty concentrating.
Answer:
colorblidness is carried on the X cromasome. since it is resessive it can be covered up. woman have 2 X cromasomes so both have to have it or she wont be color blind. men only have one X cromasome so its more likely that their just one X can have it
Explanation:
Answer: An exoskeleton is the external skeleton that supports and protects an animal's body, in contrast to the internal skeleton of, for example, a human. i think its B
Explanation: hope this helps!
Answer:
The internal membrane known as the Cristae is collapsed. The folds of the inward layer or the Cristae give an expansion in the Surface Territory which gives the Mitochondrion more areas for ATP( the vitality cash) creation to happen
hope it helps:)
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