I think the answer is organisms
Answer:
These spheres are closely connected. For example, many birds (biosphere) fly through the air (atmosphere), while water (hydrosphere) often flows through the soil (lithosphere). Interactions also occur among the spheres; for example, a change in the atmosphere can cause a change in the hydrosphere, and vice versa.
Explanation:
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Propagation is a form of asexual reproduction
Gamates cells have half the chromosomes
C they are always found in homologous pairs