This document discusses the levels of organization in living things from cells to organisms. It defines key terms like cell, tissue, organ, and organ system. It provides examples of different tissue types like epithelial and connective tissues. Examples of organs discussed include the heart, lungs, and liver. Organ systems mentioned that work together include the digestive, circulatory, and respiratory systems. The relationship between cells, tissues, organs, systems, and whole organisms is illustrated.

1. From Cells to Or
ganisms
Dr Ahmad Ali Qureshi
(MBBS,GMC)

2. 1. Define: Cell, Tissue, organ, and organ sys
tem (DK).
2. Describe two types of tissue (DK)
3. Describe two types of organs (DK)
4. Create a flow chart illustrating relationshi
p between cells, tissues, organs, systems an
d organisms (PK)
Lesson Objectives

3. Levels of Organization
 Cell—Basic unit of structure and function in orga
nisms.
 Some organisms, like bacteria and protists, are
unicellular (made entirely of one cell).
 Some organisms, like fungi, plants, and animal
s, are multicellular (made of many cells).
 In multicellular organisms, cells exhibit cell spe
cialisation. They take on specific jobs and loo
k different from each other.
 The cells also exhibit division of labor. They spli
t up the work of the organism.

5. Levels of Organization
 Tissues—Groups of similar cells that work to
gether to perform a specific function.
 4 major tissue types in animals
 Epithelial tissue
 Connective tissue
 Muscle tissue
 Nervous tissue

6. Levels of Organization
 Organs—structures made of different types of
tissues that work together to perform a specifi
c function.
 Examples
 Heart
 Lungs
 Stomach
 Small intestine
 Liver
 Large Intestine
 Gall Bladder
 Plant Roots
 Plant Stems
 Plant Leaves

7. Levels of Organization
 Organ Systems—Groups of organs that w
ork together to perform a specific functio
n.
 Examples:
 Digestive system
 Circulatory system
 Respiratory system
 Nervous system
 Muscular system
 Skeletal system
 Integumentary system (skin)
 Vascular system in plants

8. Levels of Organization
 Organism—A complete, individual living t
hing.
 Examples:
 A single person
 A single plant
 A single bacterium
 A single protist

10. Write your answers in complete sentences
Q 1: A (tissue, organ, system) is a group of the same kinds of cells that work together.
Choose the right answer.
system
organ
tissue
Q 2: Some tissues and organs work together like the members of the team. The parts
that work together are called a _____________.
cell
system
group
Q 3: The mouth, teeth, tongue, stomach and intestines all work together. Therefore th
ey are called the important parts of __________________.
digestive system
circulatory system
muscular system
Q 4: Brain, heart and lungs are some of the important _______________ in a body.
organs
tissues
cells
system
Q 5: Different tissues work together to form _________ .
cells
system
organs
Q 6: Different systems work together to form organs. True or false?
false
true

11. 11
Organization of Vertebrate Bo
dy
Tissues are groups of cells that are sim
ilar in structure and function
In humans, there are four primary tiss
ues:
-Epithelial, connective, muscle and
nerve

12. 12
Organization of Vertebrate Bo
dy
Organs are combinations of different tissues
that form a structural and functional unit
Organ systems are groups of organs that co
operate to perform the major activities of
the body
-The human body contains 11 principal or
gan systems

13. Organ Systems
 The five main organ systems that we will b
e focusing on in this unit are:
 The Respiratory System
 The Circulatory System
 The Reproductive System
 The Digestive System
 The Excretory System

14. 14
Organization of Human Body
NO Thank you!

15. 15
Digestive System
NO Thank
you!
The organs or parts of the
body that work together
to break down food into
a smaller, more useable f
orm.

16. 16
Circulatory System
NO Thank
you!
The system that carries ox
ygen and nutrients to all
cells in the body and tak
es wastes away from the
cells; it consists of the he
art, blood vessels and blo
od.

17. 17
Respiratory System
NO
Thank you!
The system involved in th
e inhalation of and diffusi
on of oxygen into the blo
od stream, and the remo
val of carbon dioxide fro
m the body via exhalatio
n

18. Excretory System
The system resp
onsible for the r
emoval of exce
ss water and w
aste from cell r
eactions in the
body

19. Reproductive System
The male and female reproductive systems are responsi
ble for the production of sperm and ova (eggs), the fertil
isation of ova by sperm, and the gestation of a fertilised
ova into a foetus (unborn baby)