BIOLOGY - Cells - What Are Cells

Cells are the fundamental building blocks of all living organisms, from simple bacteria to complex humans. They vary in size and function, with some visible to the naked eye, like a chicken egg yolk, and others requiring a microscope. The human body contains around 50 trillion cells, each performing specific tasks. While some cells operate independently, most work together in multicellular organisms to perform complex functions, such as heart cells pumping blood. Understanding cells' diversity and roles is crucial to comprehending life itself.

What is the smallest unit that can be considered a living thing?

• A molecule

• A cell

• A tissue

• An organ

Approximately how many cells are in the human body?

• 1 million

• 50 trillion

• 100 trillion

• 1 billion

Which of the following is an example of a cell large enough to be seen by the human eye?

• The yolk of a chicken egg

• A skin cell

• A red blood cell

• A nerve cell

What is a common function shared by all cells?

• Swimming

• Producing energy

• Photosynthesis

• Creating pigments

In multicellular organisms, how do cells typically function?

• By forming simple structures

• By competing with each other

• By working together to perform complex tasks

• Independently, without interaction