Why can't human beings be unicellular organisms?

Answer 1

The cells that make up complex organisms are specialised, that is, they have a particular job to perform within the organism. They may be blood cells, or neural cells, or liver cells. Their specialisation means they cannot provide for themselves. Without the other body systems to remove their waste and provide them with oxygen, water, energy and nutrients they will not function.

Answer 2

A cell of multicellular organisms depend on communication and cooperation among specialized cells, therefore unicellular organisms do everything that you would expect a living thing to do. They grow, respond to the environment, transform energy, and reproduce.

Answer 3

Human beings do start life in the form of a unicellular organism known as a zygote, although the zygote does rapidly divide into numerous cells to form the embryo. There is only so much that you can do with a single cell. Complex structures such as brains, eyes, arms, livers, etc., cannot be formed from the cytoplasm or organelles of a single cell, they have to be built from numerous cells. Unicellular organisms actually are capable of getting to be surprisingly large; the largest is the slime mold (which is not actually mold). But it is an entirely mindless creature, it has no brain, just a nucleus. It has no more intelligence than any single cell taken from a multi-cellular organism. A cell nucleus can regulate the activities of a cell, but it does not think. It only does what it is programmed to do.

Answer 4

Because they are dependent on other cells for their survival, such as erythrocytes to deliver the oxygen and food needed.

Answer 5

In most cases, no. However, there are many cell lines used by researchers that have come from multicellular organisms. These cells are capable of living outside of the organism.

Answer 6

It can't cause it doesn't want to!