The is a membrane-bound organelle that contains an organism's genetic material and control and regulate cellular processes.

Eukaryotic cells contains a nucleus and other organelles that are the bound by membranes, also referred to as membrane bound organelles multicellular organisms have a nucleus, have a membrane bound organelles, unicellular organisms and contains organelles. The Eukaryotic cells produces ribosomes inside of its nucleus.

The hawk receives 0.1% energy from the caterpillar although the caterpillar gets eaten by another bird smaller than the hawk first