How do the oxygen (O2) and carbon dioxide (CO2) levels change over time?

What is the function of the somatic nervous system? connects the brain and the spinal cord to the rest of the body carry signals to the muscles and glands includes all nerves controlling the muscular system and external sensory receptors controls internal organs like the heart and bladder

Some plants have reproductive structures that them reproduce using natural forces or animals. how does the reproductive structure shown here ensure the reproductive success of plants?

As a result of climate change earths temperature is rising and sea ice is melting what is a likely effect? answer : populations of walruses and polar bears will decline