List 4 levels of an organization in an evosystem from smallest to largest?

Ecosystems are organized to better understand the frame of reference in which they are being studied. They are organized from smallest to largest; organism, population, community, ecosystem.

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both male and female gametes are produced by meiosis of the germ cells. therefore, both male and female gametes are haploid. one male and one female gamete unite during the fertilization to form the diploid zygote. in seed bearing plants, pollen grain is the male gametophyte, which produces sperm cells.

the correct answer is d