Cells and tissues
Types of cells
Euokaryotic
Animal cell
Plant cell
Prokaryotic
The Cell
The Organism’s Basic Unit of Structure and Function
‫بدائية‬
Prokaryotic
Micro-organisms
Types
of cells
‫متقدمة‬
Eukaryotic
All other forms of
life
Differences ‫أوجه االختالف‬

A major difference ‫ الفرق األساسى‬between prokaryotic and
eukaryotic cells is the location of chromosomes ‫موضع الصبغيات‬

In an eukaryotic cell, chromosomes are contained in a true nucleus (‫) النواة‬.

In a prokaryotic cell, the DNA is concentrated in the nucleoid (‫)شـبه نواة‬
without a membrane (‫ ) بدون غـشاء‬separating it from the rest of the cell.

In prokaryotic cell, DNA is a single strand (‫ )أحادى الشريط‬or double strand
(‫ )ثنائى الشريط‬DNA. But in eukaryotic cell, DNA is double strand.
‫‪Prokaryotic cells‬‬
‫المادة الوراثية‬
‫الريبوسومات‬
‫غشاء الخلية‬
‫جدار الخلية‬
‫محفظة‬
‫اسواط‬
‫بكتيريا عصوية تحت‬
‫المجهر االلكتروني‬
‫تركيب الخلية بدائية النواة‬
‫نموذج تركيب البكتيريا‬
‫العصوية‬
Generalized Prokaryote
Nucleoid DNA
Plasmid DNA
Cytosol
Flagellum
Capsule
Plasma
Membrane
Cell Wall
Animal cell
Plant cell
Not in plant cell:
-Lysosomes
- centrosomes with
centrioles
- flagella
7
Generalized Cell
Animal
Cell
Centrioles
Chloroplasts
Mitochondria
Golgi
Nucleus
Endoplasmic
Reticulum
8
Plant
Cell
characters
Cell wall
Plasma Membrane
Animal cell
o Absent
O only cell membrane
Vacuole
O One or more small
Chloroplast
O Absent
Lysosomes
vacuoles.
O Present
Plant cell
O Present
O cell wall and a cell
membrane.
O One, large central
vacuole .
O Present
O Absent
Centrioles
O Present
O Absent
Flagella
O Present
O Absent
Example of plant cell ( onion)
Epidermal Onion Cell
Tissues
• Definition: a group of closely associated cells
that perform related functions and are similar
in structure
• Four basic types of tissue…function
– Epithelium…covering
– Connective tissue…support
– Muscle tissue…movement
– Nervous tissue…control
A- Epithelia
Epithelium: sheet of cells that covers a body surface or lines a
body cavity; also form most of the body’s glands
Classification of epithelia
• According to thickness
– “simple” - one cell layer
– “stratified” – more than one layer of cells (which are
named according to the shape of the cells in the apical
layer)
• According to shape
– “squamous” – wider than tall
– “cuboidal” – as tall as wide
– “columnar” - taller than wide
Simple columnar epithelium
Simple cuboidal epithelium
Stratified squamous epithelium
B- Connective tissues
Classification of connective tissue :
1) Connective tissues proper
•
•
•
•
•
•
Adipose
Elastic
Areolar
Reticular
Fibrous
Mucoid
2) Cartilage
3) Bone
4) Blood
Adipose connective tissues
C- Muscles
Three types
1. Skeletal
2. Smooth
3. Cardiac
Cardiac muscle
Skeletal muscle
Ocular Lens
Body Tube
Nose Piece
Arm
Objective
Lenses
Stage
Clips
Diaphragm
Stage
Coarse Adj.
Fine Adjustment
Light Source
Base
Skip to Magnification Section
Parts of the Microscope
Arm
Parts of the Microscope
Diaphragm
Light Source
Parts of the Microscope
Stage
Stage Clips
Parts of the Microscope
Revolving
Nosepiece
Objective
Lenses
Parts of the Microscope
Ocular Lens
Parts of the Microscope
Coarse adjustment knob
Used only when low power objective is used!!
Parts of the Microscope
Fine adjustment knob
Important Vocabulary :
magnification \mag-ne-fe-'ka-shen\ n
1. apparent enlargement of an object
2. the ratio of image size to actual
size
A magnification of "100x" means
that the image is 100 times bigger
than the actual object.
resolution \rez-e-loo-shen\
n 1. clarity, sharpness
2. the ability of a microscope to show
two very close points separately
Magnification
ocular power = 10x
low power objective = 20x
high power objective = 50x
a) What is the highest magnification you
could get using this microscope ?
500x
Ocular x high power = 10 x 50 = 500. (We
can only use 2 lenses at a time, not all
three.)