Cell Theory

On Earth, we divide all living organisms into cells.

The concept of the idea of cell theory is actually that cells are the structural basic units for all of the world’s organisms.

 

Question 1 of 2

1. Chloroplasts are the key structure in the process of…

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B.
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D.

Question 1 of 2

Question 2 of 2

2. All living organisms on Earth are divided into cells. All cells (animal- and plant-like) look the same. True or False?

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B.

Question 2 of 2


 

Next lessons: Photosynthesis

This video transcript is added for your convenience. A cell is a small compartment that holds the biological equipment required for keeping organisms successful and alive. A living thing may be a single-celled organism or they could be highly complex things such as human beings.

Then there are also smaller pieces that are making up cells, for example, organelles and macromolecules. In a larger organism, the most important purpose of cells is to organize. A cell is holding various pieces and all cell types have different purposes. By dividing various responsibilities among the different sets of cells, an organism makes it easier for itself to grow and survive.

There are several types of cells. When you’re in a biology class, you usually will be working with animal-like cells and plant-like cells. We call that “animal-like” as animal types of cells could include anything from one of your nerve brain cells to any tiny microorganism.

Easier to identify are plant cells because plant cells come with a protective structure that we call the cell wall, which is made of cellulose. So plants have the cell wall and animal-like cells do not. Plant cells also contain organelles, for example, green chloroplast or big vacuoles that are water-filled. Chloroplasts are actually the key structures in the photosynthesis process.

Cells are typically unique to all types of organisms. When you look at the simplest of organisms, you will find cells that don’t have a specific nucleus (prokaryotes) while other cells may include several hundred nuclei (multinucleated).

In humans, there are hundreds of different types of cells. You can find red blood cells, for example, that are being used for carrying oxygen (O2) throughout the human body while other cells are specific to human heart muscles. And though cells may be very specific and different, basically they are compartments that are surrounded by a sort of membrane.

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