wunder beta🔬 Cells, Tissues, and Organ Systems
Zoom from a single tiny cell all the way up to a whole living body, one level at a time.
What you’ll learn
- The Building Block: CellsExplain that cells are the basic unit of life and name the main parts of an animal cell and their jobs.Cells are the smallest living units and the basic building blocks of every organism. An animal cell has a membrane that controls what enters and leaves, cytoplasm that fills it, a nucleus that stores its DNA instructions, and mitochondria that release energy. Cells come in different shapes because they do different jobs.
- From Cells to OrgansDescribe how similar cells form tissues and how different tissues form organs, and order the levels of organisation.Similar cells group together to form a tissue, such as muscle tissue made of muscle cells. Different tissues combine to form an organ, like the heart. The levels of organisation always run smallest to largest: cell, tissue, organ, organ system, organism, with each level built from the one below it.
- Systems and the Whole OrganismExplain how organs form organ systems and how systems together make the whole organism, using the circulatory system as an example.Several organs that work together form an organ system, such as the heart and blood vessels making the circulatory system. Many systems working side by side make up the organism, the complete living thing. Following one chain, a muscle cell builds muscle tissue, which forms the heart, part of the circulatory system, part of the whole body.
Questions this course answers
Why do scientists call the cell the basic building block of life?
A cell is the smallest living unit, and every living thing is built from one or more cells.
Which part of the cell acts as the control centre and holds its instructions?
The nucleus stores the cell's DNA instructions, so it controls what the cell does.
What is the main job of the cell membrane?
The membrane is the outer skin that decides what can enter or leave the cell.
What is a tissue?
A tissue is many similar cells grouped together to do one shared job, like muscle tissue.
The heart is made of several tissues working together. This makes the heart an example of a what?
An organ is a body part built from several tissues that work together, and the heart fits that description.
Which order shows the levels of organisation from smallest to largest?
The levels build up in this order: cell, then tissue, then organ, then organ system, then organism.
Grounded in trusted sources
- BBC Bitesize
- Britannica Kids
- Khan Academy
- KidsHealth
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