A. Zoology
1. A subset of biology
dealing with animals.
B. Cells
1. Cells are the basic
organizational units of
life.
2. Cells can be
prokaryotic or
eukaryotic.
3. Prokaryotic cells
have no nucleus.
4. Eukaryotic cells
have a nucleus
containing DNA.
5. All eukaryoic cells
have three basic parts.
a. A plasma membrane
b. Cytoplasm
c. A nucleus
C. Plasma membrane
1. Outer boundary of
the cell.
2. Fluid mosaic model –
a membrane has two
layers of proteins and
phospholipids.
3. The membrane is
constantly changing shape
and shifting. There may
be many types of
proteins dispersed
through the membrane.
4. The membrane is
selectively permeable.
This means they let
some things through
while keeping others
out.
D. How do things
cross the
membrane? There
are 7 ways!
1. Simple diffusion –
the movement of
particles from areas of
high concentration to
areas of low
concentration.
2. Facilitated diffusion
– carrier proteins help
molecules get across
the membrane.
3. Osmosis – the
diffusion of water.
Tonicity refers to the
relative concentration
of solutes in water
inside and outside the
cell.
a. ISOTONIC – same
concentration inside as
outside the cell. (no
effect on cell)
b. HYPERTONIC –
Concentration is higher
outside the cell than
inside the cell. (The
cell shrinks)
c. HYPOTONIC –
Concentration is higher
inside the cell than
outside. (the cell
swells)
4. Filtration – uses
water pressure to
force molecules across
the membrane.
5. Active transport –
moves molecules from
areas of low
concentration to high
concentration.(opposite
of diffusion) Requires
ATP energy.
6. Endocytosis – The
bulk movement of
particles across the
membrane INTO the
cell. There are 3
types!
*a. Pinocytosis – the
taking in of fluids.
*b. Phagocytosis – the
taking in of solids.
*c. Receptor-mediated
endocytosis ~ uses a
protein to bring
molecules into the cell.
7. Exocytosis –
Molecules are removed
from the cell in
packets called vesicles.
E. Organelles
1. VACUOLE – a
membrane-bound fluid
filled sac within the
cytoplasm of a cell.
Animal cells have many
small ones.
2. MITOCHONDRIA –
among the largest
organelles, surrounded by
a double membrane,
produces small energy
packets that can be used
by the cell. Powerhouse .
3. NUCLEUS – large round
body, the most prominent
structure in the cell, it is
enclosed by a nuclear
membrane. Chromosomes
with genetic info are inside
the nucleus.
4. RIBOSOMES – most
numerous and smallest
of the organelles, it is
the site of protein
synthesis. Often
associated with
endoplasmic reticulum.

5. ENDOPLASMIC
RETICULUM
– Makes proteins and
hormones.Transports
material throughout
the cell. Comes in
smooth and rough.
6. GOLGI BODIES –
flattened stacked sacs,
acts as a distribution
center, packages and
routes products
throughout the cell.
7. CILIA – Short hairlike projections used
for locomotion and to
sense the environment
8. FLAGELLA – long
thread-like structures
used for locomotion.
Cilia and flagella have
filaments made of a
protein called tubulin
9. MICROFILAMENTS
– thin protein fibers in
cytoplasm, helps the
cell change shape.
10. MICROTUBULES –
hollow cylinders of
protein, provide
support.
11. CYTOSKELETON –
holds’ the cell upright
and helps give it shape,
helps it move, and
holds other organelles
in place.
12. LYSOSOMES – bags
of enzymes, they are
involved in breaking down
material.
“stomach” >
13. CYTOPLASM – a
jelly-like substance
made of proteins
dissolved in water.
A semifluid phase of
cytoplasm where
metabolic reactions
occur is called the
cytosol.
F. Levels of Organization
1. First level –
protoplasmic organization.
Examples include euglena,
amoeba, paramecium.
2. Second level –
cellular organization,
division of labor. Ex.
some sponges.
3. Third level – tissue
level, no organs. Ex.
Jellyfish
4. Fourth level – organ
level, organs composed
of one or more tissues.
Ex. flatworms.
5. Fifth level – system
level, organs work
together to form
systems. Ex. most
animals.
G. Tissue Types
A tissue is a group of
similar cells specialized
for a specific job.
There are 4 types of
animal tissue.
1. EPITHELIAL
– Usually covers or lines
something.
– Renewable
– Can be found lining the
intestine, in the
kidneys, the skin, etc.
– Classified on the basis
of shape and number of
layers present.
– Simple: one layer
– Stratified: two or
more layers
– Squamous: flat
– Cuboidal: cube shaped
– Columnar: column
shaped
2.CONNECTIVE TISSUE
– Supports and binds
– Loose connective tissue
helps connect skin to
underlying muscle.
Fiberous connective
tissue creates very
strong cords like
ligaments (connect bone
to bone) and tendons
(connect muscle to
bones or other
muscles.
Adipose tissue – fat
Cartilage – hard and
flexible tissue for
support
Bone – hard. Provides
protection and support.
Spaces within bone or
cartilage which house
the living cells are
called lacunae.
Blood – a fluid
connective tissue that
transports material
throughout the body.
3. Muscle tissue
– Skeletal muscle
attaches to bone and
is used for movement
– Smooth muscle
creates a churning
motion and helps move
material around inside
the body.
– Cardiac muscle is
found in the heart.
Nervous tissue
– Neurons are impulse
conducting cells
– Neuroglia are involved
in protection,
support, and
nourishment
– Peripheral glial cells
form sheaths that
protect the nervous
system.