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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.