Looking Inside Cells
Section 2-4
7th grade Life Science
I.
Introduction to Section 2-4
specific functions within the cell
A. Organelles carry out _________________________________________________
II. Enter the Cell
layer of non-living material
A. Cell Wall — a rigid ___________________________________________________
do not have cell walls
1. The cells of animals ____________________________________________
__________________________________________________________________
Protect and support the cell
2. A plant’s cell wall helps to ______________________________________
__________________________________________________________________
A strong material called cellulose
3. The cell wall is made of _______________________________________________
_____________________________________________________________________
Many materials including water can pass through it
4. Many materials, ______________________________________________________
B. Cell Membrane
have cell membranes
1. All cells _______________________________________________________
what substances come into and out of a cell
2. The cell membrane controls ___________________________________________
III. Sail on to the Nucleus
As the cells control center , directing all of the cell’s
A. You can think of the nucleus __________________________________________________
____________________________________________________________________________
activity
B. Nuclear Envelope
Protects the nucleus
1. The nuclear envelope __________________________________________________
In and out of the nucleus through pores in the
2. Materials pass ________________________________________________________
_______________________________________________________________________
nuclear envelope
C. Chromatin
1. Chromatin contains ___________________,
the ____________________
genetic material
instructions for
directing the cell’s functions
__________________________________________________________________
D. Nucleolus
ribosomes are made
1. Is where _______________________________________________________
2. Ribosomes are the _____________________________________________
organelles where protein is produced
IV. Organelles in the Cytoplasm
A. The cytoplasm, the region ____________________________________________
between the cell membrane and the nucleus
gel-like fluid
B. Made up of a clear, thick, _____________________________________________
C. The fluid in the cytoplasm is __________________________________________
constantly moving
D. Mitochondria
“powerhouses” of the cell
1. Mitochondria are known as the __________________________________
E. Endoplasmic Reticulum
1. The endoplasmic reticulum’s passageways
Carry
proteins and other materials from one part of the cell to another
______________________________________________-______________________
F. Ribosomes
of the endoplasmic reticulum
1. Attached to some surfaces ______________________________________
2. Ribosomes function as _________________________________________
factories to produce proteins
In the space provided draw and label EITHER a plant cell or an
animal cell. Use the information provided on pages 64 or 65.
G. Golgi Bodies
Receive protein and other newly formed materials from the
1. The Golgi bodies ______________________________________________________
endoplasmic reticulum , package them, and distribute them
______________________________________________________________________
to other parts of the cell.
______________________________________________________________________
Release materials outside the cell
2. The Golgi bodies also ___________________________________________
H. Chloroplasts
1. Only the cells of __________________________________________________
plants and some other organisms that make their own food
from sunlight and use it to make food
2. Chloroplasts captureEnergy
___________________________________________
Leaves green
3. Chloroplasts make ____________________________________________
I. Vacuoles
storage areas for cells
1. Vacuoles are ___________________________________________________
J. Lysosomes
round structures containing chemicals
1. Lysosomes are small ___________________________________________
food particles, old cell parts,
2. Some chemicals break down Large
____________________________________
3. You can think of lysosomes as ___________________________________
the cell’s cleanup crew
V. Specialized Cells
A. Cells are often quite __________________________________________________
different from each other and are
______________________________________________________________________
specialized to perform specific functions
Cells are organized into tissues, organs,
1. In many-celled organisms, ______________________________________
and organ systems
__________________________________________________________________
a. A tissue is a group of similar cells that work together
to carry out a life process or perform a
______________________________________________________________________
specific function
______________________________________________________________________
b. An organ is made of Different kinds of tissues that function
together
______________________________________________________________________
c. An organ system is a group
of organs that work together to perform a major function
____________________________________________________________________
Answer Section 2-4 Assessment questions on page 67, numbers 1a, 2a, and 3b
using complete sentences. Answer on your own paper.