Levels of organization
Life Science 1
Learning objectives
1.Learn the levels of organization for organisms.
2.Learn what each of these levels are.
3.Be able to provide REAL examples for each level.
4.Be able to distinguish between living and nonliving.
5.Understand that living things may be made of one cell, or
many varied cells.
Levels of organization
Atom
Molecule
Organelle
Cell
Tissue
Organ
Organ
system
Organism
atom
Atom: the SMALLEST unit of matter.
Every solid, liquid, gas or plasma is made of atoms.
Every atom is made of a nucleus (where protons and neutrons
are held).
What are the dots on these
lines around the picture of the atom?
molecule
Molecule: collection of atoms held together by chemical
bonds. The smallest particle of a chemical element.
Bonds= result of e- sharing or exchanging.
organelle
Organelle: organized, specialized structures within a cell.
What is a cell?
Cell: The smallest structural and functional unit of an
organism.
Humans= 70 TRILLION cells… but guess what? Most aren’t human
Levels of organization for organisms
Tissue
Tissue: a group of similar cells from the same origin, that
together carry out the same function
Tissue: which are tissues and which are not
A leaf?
Blood?
Cardiovascular system?
Vascular matter of plants?
Organ
Organ: a group of tissues working together to perform the
same function.
Which is an organ and which is not
Human head?
Brain?
Feet?
Fingers?
Urinary Tract?
Bladder?
Organ system
Organ system: a group of organs that work together to produce
one or more functions.
Organ system: Which are systems and which are not?
Nerves + human brain?
Flower + fruit?
Bladder + human skin + human hair?
Heart + veins + blood?
Leaves + stems?
Organism
Organism: any contiguous living system.
(Rules) To be an organism, these must be true:
1.Respond to stimuli
2.Can reproduce
3.Can grow
Organisms: which are organisms and which are not
A dog?
The fungus on your dad’s feet?
A crystal geode rock?
A potato?
The virus that makes you throw up?
Pond water?
Living vs nonliving organisms
You tell meLet’s list some examples of each.
Characteristics of each? What do they have in common? What
distinguishes a living thing from a nonliving thing?
Unicellular vs multicellular organisms
Unicellular: an organism that only consists of ONE cell.
Examples: bacteria, some fungi, some algae
Multicellular: an organism that consists of MORE THAN ONE
cell.
Examples: ?
So… what are Organelles? Let’s discuss tomorrow
1.Cell membrane
2.Nucleus
3.Cytoplasm
4.Mitochondria
5.Endoplasmic Reticulum
6.Ribosomes
7.Golgi Apparatus