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-tovolume 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.