C4 plants occur more commonly in desert conditions because . a. they can fix carbon at the lower CO2 concentrations that develop when the stomata are closed b. they store carbon by incorporating CO2 into organic acids that are later catabolized c. they produce water as a product of their photosynthetic pathways d. they produce carbon dioxide internally via photorespiration the stomata open at night and close in the day

a. they can fix carbon at the lower CO2 concentrations that develop when the stomata are closed

Explanation:

C4 plants are those that have the capacity to fix CO2 even when a tiny concentration of it is available.

Desert condition is characterized by dryness and strong heat with both condition capable of creating water stress in plant as a result of evapotranspiration. In order to reduce evapotranspiration rate, desert plants (most C4 plants) close their stomata during the day.

Stomata closure limit the diffusion of CO2 into desert plants and the small concentration of CO2 that results is utilized by a special enzyme in the plants.

The correct option is a.

the oceanic zone is typically defined as the area of the ocean lying beyond the continental shelf, but operationally is often referred to as beginning where the water depths drop to below 100 meters (328 feet), seaward from the coast to the open ocean.

explanation:

carbohydrates: (starches and sugars) composed of carbon, hydrogen, and oxygen.

lipids: (fats, oils, and waxes) are made of carbon and hydrogen atoms.

nucleic acids: contain hydrogen, oxygen, nitrogen, carbon, and phosphorus. they are polymers of nucleotides. a nucleotide has three parts, a 5-carbon sugar, a phosphate     (-po⬇️4) group, and a nitrogenous base.

proteins: made up of nitrogen, carbon, hydrogen, and oxygen. they are polymers of amino acids.