Answer:
Gas exchange occurs at two sites in the body: in the lungs, where oxygen is picked up and carbon dioxide is released at the respiratory membrane, and at the tissues, where oxygen is released and carbon dioxide is picked up.
Explanation:
By trapping heat, greenhouse gases contribute to our planet's warming. Because of its involvement in the Earth's carbon cycle and nitrogen cycle, the biosphere influences the amounts of some of the major greenhouse gases such as methane, carbon dioxide, and nitrous oxide.
The correct option is A.
The DNA from one specie differ from the DNA of another specie on the basis of their base ratio. The base ratio refers to the percentage of purine to pyrimidine in a DNA molecule. The base ratio is the one that is responsible for the variability that is observed in chromosomes from different species.