Answer:
A.
Explanation:
Because the trait undergoes a secondary loss; it has been there but it doesn't always appear in all generations.
Biological macromolecules are important cellular components, they have a wide array of functions necessary for survival and growth of living organisms. There are four major classes of biological macromolecules
-carbohydrates
-lipids
-proteins
-nucleic acids.
Radiation is the thermal energy transfer
Animals and plants need to get rid of carbon dioxide gas through a process called respiration. Carbon moves from fossil fuels to the atmosphere when fuels are burned. When humans burn fossil fuels to power factories, power plants, cars and trucks, most of the carbon quickly enters the atmosphere as carbon dioxide gas.
