The correct answer is (B) Photosynthesis and diffusion from the air
Dissolved oxygen enters the water from photosynthesis and through air. The The aeration of water can be caused by wind. From the air oxygen diffuse into the water and gets mixed in the it through circulation. The oxygen is also produced as a waste product of photosynthesis from blue-green algae, phytoplankton, etc which is added in water.
Answer:
answer is the ability to do work
Meiosis 1 results in two homologous chromosomes being pulled apart creating two chromosomes that share the same DNA, Meiosis 2 results in two sister chromatids being pulled apart, creating four haploid cells.
C.<span>trees going dormant in winter to survive unfavorable conditions</span>