Answer:
When the level of release of carbon dioxide during respiration and use of carbon dioxide during photosynthesis this results in a compensation point. At compensation point the net available carbon dioxide to phototrophs becomes zero. As, carbon dioxide is the chief ingredient for photosynthetic products like glucose and oxygen. These products are used up during the process of respiration. When the rates of two processes photosynthesis and respiration becomes equal. Phototrophic organisms will not be able to compensate for lack of carbon dioxide levels. Phototrophs will not be able to produce their food in the form of glucose and hence will not be able to respire too. This will result in lack of overall available food from phototrophs and lack of available oxygen for respiration. This will result in decline of organisms on earth.
The answer is Desalination. Desalination is the process of removing minerals from salt water. Most ocean-water consumption and supply are most likely to be very particular in this places like USA, Europe, Africa and UN. Desalination depends on the capacity and facility of the place.
Warm air mass advances on a cold air mass, causing rain.
Molecular Biology
This field of study deals with everything related to macromolecules, thus, what you will need for molecular biology would be something you could get proteins and nucleic acids from. Among the choices, the DNA of a pig and a calf would be the most helpful.
Comparative Anatomy
Comparative anatomy is a field of study that focuses on any similarities or differences between the anatomy or structure of different animals or species in general. Among the options, having the limb structure of a pig and a calf would allow you to practice the field since you have a structure to compare.
Developmental Biology
In this field, your concern would be how species grow and develop. For you to properly observe the growth and development, you must have the embryo of a pig and a calf. Therefore, among the options, this is the correct piece of evidence for this field.
IN SUMMARY:
Molecular Biology - Both DNA of a pig and a calf
Comparative Anatomy - Both limb structure of a pig and a calf
Developmental Biology - Embryo of a pig and a calf