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Characteristics of Living Things
Answer Activity No. 2.1 CHARACTERISTICS OF LIFE
The study of life
Living things are known as organisms.
The living world and the non-living world are mixed. As you
look out the window here at school or as you investigate any
environment you will find a mixture of the two. How can we
identify something as an organism?
For each of the items listed below state a reason that
makes it living or non-living:
Clouds
Mushrooms Fire
Worm Automobile
What characteristics do
all living things share?
1. Living things are made up
of units called cells (Organized)
•Some organisms are made of only one
cell and some are made of trillions of cells.
•Cells are small self-contained units of
living material that are separated from the
surroundings by a barrier.
Unicellular – organism made of
only one cell
Multicellular
– organism made of
more than one cell.
In complex multi-
cellular organisms
such as humans,
many different types of
cells work together to
perform the functions
needed by the
organism.
Spirogyra is a common freshwater alga hydra (animal)
2.Living things reproduce:
Reproduction is the life process that
provides for continuation of the species.
An individual will not die if it does not
reproduce but the species will end if no
members reproduce.
Sexual reproduction -requires cells from 2 parents to
create a new individual different
from each parent. Common in
multi-cellular organisms (trees,
birds etc.)
Asexual reproduction -requires only one parent.
Offspring is identical to parent.
3.The traits of living things are
determined by the genetic code: (Composed of DNA)
When organisms reproduce they pass on
genetic information in the form of DNA to the
offspring.
• In sexually reproducing organisms the offspring
obtain a mixture of genetic information from
each parent.
• In asexually reproducing organism the offspring
have identical genetic information to the parent
4.Living things grow
and develop.
Every organism has its own
life-cycle – a pattern of
growth and change that
occurs over the organisms
lifetime.
(GROWTH and DEVELOPMENT)
5.Living things obtain and
use materials and energy. (Metabolism)
Examples
• Oxygen and sugar are needed by organisms to
make energy.
• Food is needed to help build the body
Chemical reactions take place in the body to
convert the materials from the environment into
forms usable by the organism.
Metabolism is the collection of all the reaction
that take place within an organism.
Examples of Metabolic
Reactions:
•Building Cells
•Breaking down cells
•Converting oxygen and
glucose to energy and
carbon dioxide.
6. Living things respond to
their environment. (SENSITIVITY)
Organisms live in a constantly changing
environment.
Examples:
Light, temperature and amount of water
change from day to day and season to
season. Plants and animals must respond to
these changes or they will die.
7. Living things maintain and a
stable internal environment. (HOMEOSTASIS)
The steady state (balance) inside an organisms
body is known as HOMEOSTASIS.
While the environment outside changes an
organism must be able to keep conditions inside
mostly the constant. If homeostasis is disturbed the
organism will become sick and will die if the
balance is not fixed.
Life has changed
significantly over the
history of the earth.
The process of this
change is known as
evolution.
8. Taken as a group, living
things change over time (Evolutionary Adaptation)
CHECK YOUR UNDERSTANDING #1:
In essay format discuss what
characteristics all living things have in
common and how life on earth is different.
Be sure to include the following terms in
your response in a way that demonstrates
an understanding of the term:
Organism, unicellular, multi-cellular,
sexual reproduction, asexual reproduction,
life cycle, metabolism, homeostasis,
evolution
Living things (organisms) can be distinguished from
non living things by several characteristics and abilities. All
organisms are comprised of cells. Whether organisms are
made up of a single cell (unicellular) or many cells (multi-
cellular) they are able to carry out similar processes.
To continue the species all organisms must be able to
reproduce. Some species reproduce by combining genes
from two parents in a process known as sexual reproduction.
Some species reproduce asexually and produce a genetically
identical offspring.
All organisms carry on chemical reactions in their body,
called metabolism, that allow them to maintain a state of
homeostasis or internal balance. Over time, life on earth has
evolved to include these common characteristics, but life has
developed many different ways of accomplishing these
processes.
Sample Essay
Sub-Units of metric
system used in Biology
Tools for length
Kilo 1000 times
Centi 1/100th
Milli 1/1000th
Micro 1/1,000,000th
Nano 1/1,000,000,000
Measuring Tape
Ruler
Ruler
Light Microscope
Electron
Microscope
The Scale of Biology
For each of the following organisms listed below
choose the appropriate scale of measurement
(metric) for scientists to use:
• Weight of an Elephant __________________
• Width of a Bacteria _____________________
• Temperature of a liquid ________________
•Length of a feather ___________________
•Weight of a feather ___________________
• Height of a person ____________________
Kilograms
Micrometers
Celsius or Kelvin
Centimeters
Grams
Meters
Cell Structure
& Function
http://koning.ecsu.ctstateu.edu/cell/cell.html
Definition of Cell
A cell is the smallest
unit that is capable of
performing life
functions.
First, what is a cell?!
It took a long time for people to discover cells
and figure out what they were all about.
They need sophisticated equipment
(microscopes) to be able to see cells.
Every thing we know about cells we call
“cell theory”.
Examples of Cells
Amoeba Proteus
Plant Stem
Red Blood Cell
Nerve Cell
Bacteria
Cell Theory says that….
1. All living things are made of cells.
2. Cells are the basic units of
structure and function in all living
things. In other words, cells are
like the building blocks of all living
things.
3. New cells are only made from
existing cells.
There are two types
of cells:
Prokaryotic Cells and
Eukaryotic Cells
These are two distinct types of cells
with STRUCTURAL differences.
Prokaryotes
Bacteria
Eukaryotes
Animal Plant
PROKARYOTE CELL
A single celled
organism that does
not have a nucleus.
“Pro” means before “Karyon” means nucleus
Traits of Prokaryotes:
(pro-care-ee-ohts)
1. They do not have a nucleus, and their genetic material is not stored in the nucleus.
2. They have some organelles, but not many.
3. They are less complicated that eukaryotes.
4. All bacteria are prokaryotes.
PROKARYOTIC
ORGANISM
The first cells to appear on Earth
were prokaryotic cells. A prokaryote
is an organism made of a single
prokaryotic cell. The earliest
prokaryotes may have arisen more
than 2.5 billion years ago.
Bacteria may be small but they are powerful!
During the 14th century, 25% or ¼ of Europe was
killed by a killed by a bacteria called the Bubonic
Plague, also called Black Death. This bacteria
was spread through fleas and rodents.
DAVAO CITY--The NPA bandits have employed
bioterrorism in its attacks against military and
civilian targets, latest military records show.
He said that the shrapnel used by the NPA on their
bombs were intentionally contaminated with
bacteria in order to further improve its lethality.
Enterobacter Cloacae and
Streptococcus Agalacteiae
The most recent international incident involving the
alleged use of biological weapons happened in
Syria on August 21, 2013 during which hundreds of
people were killed including women and children.
But at the same time we
need bacteria to live!
Bacteria are decomposers and without them all other organisms would not be able to survive.
We use bacteria in our digestive system to help digest our food. There are approximately ten
times as many bacterial cells as human cells in the human body!
We could not make cheese or yogurt without bacteria.
EUKARYOTE CELL
A more complex cell with a
nucleus and many
organelles.
“Eu” means true “Karyon” means nucleus
EUKARYOTIC
ORGANISMS
Eukaryotes are organisms made of one
or more eukaryotic cells. The earliest
eukaryotes, like the first prokaryotes, were
single-celled organisms. They arose about
1 billion years later than the earliest
prokaryotes. Later, multicellular
eukaryotes arose. Every type of
multicellular organism that exists is made
up of eukaryotic cells.
TRAITS OF EUKARYOTES:
(you-care-ee-othts)
1. They all have a nucleus where the genetic material of the cell is stored.
2. They have many organelles that work together to help the cell function.
MORE TRAITS OF EUKARYOTES:
(you-care-ee-othts)
> Eukaryotic cells are much more complex
then prokaryotic cells.
> They can be just one cell or can make up
more complex multi-cellular organisms.
> All plants, animals, fungi, and protists
are eukaryotic cells.
Think – Pair - Share
What do you think is the
main difference between
a prokaryotic cell and a
eukaryotic cell?
The NUCLEUS!
Prokaryotic cells do not have a nucleus and eukaryotic cells do have a nucleus. This
allows eukaryotic cells to make multi-cellular organisms and
perform more complex functions.
PROKARYOTIC
Do not have structures surrounded by membranes
Few internal structures
One-celled organisms, Bacteria
http://library.thinkquest.org/C004535/prokaryotic_cells.html
EUKARYOTIC
Contain organelles surrounded by membranes
Most living organisms
Plant Animal
http://library.thinkquest.org/C004535/eukaryotic_cells.html
ANIMAL and PLANT
CELLS
Cell Differentiation
Each kind of cell has a DIFFERENT
job to do…it is specialized.
I am a heart cell!
I am a skin cell
I’m a Prison Cell!
Cell
http://web.jjay.cuny.edu/~acarpi/NSC/images/cell.gif
CELL PARTS
Organelles
An organelle is a
membrane-bound structure
that carries out specific
activities for the cell.
Surrounding
the Cell
CELL MEMBRANE
Flexible and thin
covering, protects cells
Outer membrane of cell
that controls
movement in and out of
the cell
Double layer
http://library.thinkquest.org/12413/structures.html
CELL WALL
Most commonly
found in plant cells
& bacteria
Made up of
cellulose for plants.
Supports & protects
cells
http://library.thinkquest.org/12413/structures.html
Inside the Cell
NUCLEUS
Largest organelle
Directs cell activities
Separated from
cytoplasm by nuclear
membrane
Contains genetic
material - DNA
NUCLEAR MEMBRANE
Surrounds nucleus
Made of two layers
Openings allow
material to enter
and leave nucleus
http://library.thinkquest.org/12413/structures.html
Found in the nucleus
Made of DNA
Contain instructions for traits &
characteristics
http://library.thinkquest.org/12413/structures.html
CHROMOSOMES
NUCLEOLUS
Small dark area
Inside nucleus
Contains RNA to
build proteins
It is responsible for
making ribosomes.
http://library.thinkquest.org/12413/structures.html
CYTOPLASM
Gel-like mixture
Surrounded by cell
membrane
Contains hereditary
material
All organelles reside
(live and float
around in) the
cytoplasm.
(not an organelle - but important)
ENDOPLASMIC RETICULUM
Moves materials
around in cell
Smooth type: lacks
ribosomes
Rough type
ribosomes embedded
in surface http://library.thinkquest.org/12413/structures.html
Smooth Endoplasmic
Reticulum (SER)
Transports materials
throughout the cell.
It synthesizes
lipids, phospholipids,
and steroids. Cells
which secrete these
products,
Rough Endoplasmic
Reticulum (RER)
• Covered with ribosomes.
• Produces proteins.
• works in concert with
the golgi complex
to target new proteins to
their proper destinations.
RIBOSOMES
Each cell contains
thousands
Synthesizes proteins
Present in the
cytoplasm.
Present with Rough ER.
No membrane present.
http://library.thinkquest.org/12413/structures.html
(not an organelle - but important)
.
MITOCHONDRIA
Produces energy through
chemical reactions –
breaking down fats &
carbohydrates
A bean shaped organelle
that controls level of water
and other materials in cell
Recycles and decomposes
proteins, fats, and
carbohydrates http://library.thinkquest.org/12413/structures.html
VESICLES
It is a small sac/ bubble that
surrounds material to be moved
into or out of a cell
LYSOSOME
Has a lot of enzymes.
Digestive 'plant' for excess or
worn-out cell parts, food
particles and invading viruses
or bacteria.
Transports undigested
material to cell membrane for
removal
Cell breaks down if lysosome
explodes "Suicide Cells"
the cell's recycling
compartment.
http://library.thinkquest.org/12413/structures.html
Lysosomes (lys = split, some = body)
VACUOLES
Membrane-bound
sacs for storage,
digestion, and
waste removal
A vesicle
containing water
solution
Help plants
maintain shape
http://library.thinkquest.org/12413/structures.html
Central Vacuole
(Plant Cell Only)
Most plant cells
have one large
one.
Filled w/ fluid.
Helps maintains
turgor pressure
and shape of
cell.
GOLGI BODIES
separates and packages
proteins for export.
Move materials within
and out the cell (vesicles)
produces cell
membranes and
lysosomes.
The Golgi apparatus are
stacks of membrane-
covered sacs.
http://library.thinkquest.org/12413/structures.html
CHLOROPLAST
Usually found
in plant cells
Contains green
chlorophyll
Where
photosynthesis
takes place http://library.thinkquest.org/12413/structures.html
a) collections of microtubules (9 triplets)
b) found in pairs. 1 pair = centrosome.
c) Separate chromosomes
CENTRIOLE
