Answer:
cells are so small because it is structural functional unit of an organism which can be only seen through microscope
Answer:
Lipid insoluble hormones/Peptide hormones
Explanation:
Hormones produce their effect by binding to speific receptor. These receptors may be intracellular or membranal.
Membrane receptors;
The lipid insoluble hormones cannot cross the plasma membrane thus their receptors are found on plasma membrane. These are usually peptide hormones.
Examples; Insulin.
Intracellular receptors;
The lipid soluble hormones can cross the plasma membrane thus their receptors are found in cytoplasm. These are usually steroidal hormones.
Example; Testosterone.
The circulatory system is used to transfer blood
Atom -> molecule - organelle - cell - tissue - organ - organ system - organism - population - community - ecosystem - biosphere
There’s more to this but that’s whether you require more or less of the list
