How are concerns related to the skeletal system and astronauts?

What is the answer for the complicated molecules that make up living things usually contain carbon. why is carbon so important in these molecules?

The organelle pictured is found in cells of and is theorized to have once been an independent organism.

Which of the following words best matches this definition: the process in which the best adapted organisms survive and pass on their traits, while those that are not well adapted do not survive to pass on their traits. question 3 options: acquired selection natural selection artificial selection organic selection