Section 1: Introduction to Cells
Bellringer
How were cells discovered?
What enables eukaryotes to perform more specialized functions than prokaryotes?
The Discovery of Cells
______observations of organisms led to the discovery of the basic characteristics common to all living things.
Scientists first discovered cells in the ______using crude microscopes.
Observations made by scientists using more powerful microscopes in the 1800s led to the formation of the ______.
Looking at Cells
Cells vary greatly in their ______and shape.
A cell’s shape reflects its function. Cell size is limited by a cell’s surface area-to-volume ratio.
Cells can be branched, flat, round, or rectangular.
All substances that enter or leave a cell must cross the ______of the cell.
A cell’s ability to move substances across its surface can be estimated by finding its surface area-to-volume ratio.
Cells with greater surface area-to-volume ratios can exchange substances more efficiently.
Relationship between Surface Area and Volume
When comparing cells of the same shape, small cells have greater surface area-to-volume ratios than ______cells.
So, small cells function more efficiently than large cells.
Cell Features
All cells share common structural features, including a cell membrane, cytoplasm, ribosomes, and ______.
The ______is the outer layer that covers a cell’s surface and acts as a barrier between the outside environment and the inside of the cell.
The ______is the region of the cell within the cell membrane. The cytoplasm includes the fluid inside the cell called the cytosol.
A ______is a cellular structure that makes proteins.
The ______of a cell provides instructions for making proteins, regulates cellular activities, and enables cells to reproduce.
Features of Prokaryotic and Eukaryotic Cells
Features of Prokaryotic Cells
A ______is an organism made of a single prokaryotic cell.
Prokaryotic cells do ______have a nucleus or other internal compartments. The genetic material of a prokaryotic cell is a single loop of DNA.
For millions of years, prokaryotes were the only organisms on Earth.
Features of Eukaryotic Cells
A ______is an organism made up of one or more eukaryotic cells. All multicellular organisms are made of eukaryotic cells.
The DNA of a eukaryotic cell is found in an internal compartment of the cell called the ______.
All eukaryotic cells have membrane-bound organelles. An ______is a small structure found in the cytoplasm that carries out specific activities inside the cell.
Each organelle in a eukaryotic cell performs distinct functions.
The complex organization of eukaryotic cells enables them to carry out more specialized functions than prokaryotic cells.
Comparing Prokaryotes and Eukaryotes
Summary
Microscope observations of organisms led to the discovery of the basic characteristics common to all living things.
A cell’s shape reflects its function. Cell size is limited by a cell’s surface area-to-volume ratio.
The complex organization of eukaryotic cells enable them to carry out more specialized functions than prokaryotic cells.