Characteristics of Life
UPCO Review
Name ________________________________
Date ____________ Due _______________
Directions: Read the paragraphs, then fill in the blanks.
Life Processes
All living organisms need energy, which is obtained from food. Autotrophs, such as green plants,
make their own food. Heterotrophs, such as animals, obtain food from other organisms.
During respiration, energy is released from this food. All organisms need energy to survive. The
amount of energy an organism needs and how it gets that energy is different from organism to organism.
Most organisms use oxygen to release the energy stored in food. This is called aerobic respiration.
Organisms that do not need oxygen perform anaerobic respiration.
Living organisms need water. Water enables the organism to carry on its life activities. Organisms
need living space, which must provide all the organism’s needs. Every organism is adapted to the living
space in which it is found.
Living things have characteristics that distinguish them from non-living things. All living
organisms carry out the same basic life functions in order to maintain an internal equilibrium or balance
(homeostasis). An organism’s body plan and its environment determine the way that the organism carries
out the life processes. Some common life functions include nutrition (obtaining and breaking down food),
transport (carrying nutrients and wastes to and from cells), synthesis (chemical reactions which use
nutrients to make materials the cell needs), respiration (the release of energy as glucose and oxygen
combine), excretion (removing wastes), regulation (response to changes in the environment), growth
(increase in size or number of cells), and reproduction (producing offspring for the survival of the
species).
nutrition
1. The process by which an organism obtains food is called _________________________.
2. The release of energy stored in food is _________________________.
respiration
3. The removal of liquid and gaseous waste is known as _________________________.
excretion
transport
4. Nutrients are carried to all parts of the body during _________________________.
5. Regulation is a response to changes in the _________________________.
nutrition
6. An increase in the size of the organism is _________________________.
growth
7. Reproduction is necessary for the _________________________
of the species.
survival
energy
water
8. All living organisms need _________________________,
_________________________,
and
_________________________.
living space
The Cell
For all living things, the cell is the basic unit of structure and function. Life activities are
accomplished at the cell level. Humans are an interactive organization of cells, tissues, organs, and organ
systems. A virus lacks cellular organization.
Living organisms are composed of one or more cells. Cells are usually microscopic in size. The
way in which cells function is similar in all living things. Cells grow and divide, making more cells. Cells
take in nutrients, which provide the cell with energy and with the materials that the cell or organism needs.
Cells carry on all the life processes.
Cells provide an organism with structure. Organisms composed of one cells are unicellular such as
amoeba and bacteria. Organisms composed of many cells are multicellular. Plants and animals are
multicellular. Cells are organized for more effective functioning in multicellular organisms. Nerve cells
carry messages and muscle cells cause movement. Tissues are made of similar cells. Organs are made of
groups of tissues that work together. A group of organs, such as the stomach, small intestine, and large
intestine, work together as an organ system.
microscopic
9. Most cells are _________________________
in size.
grow
10. Cells _________________________
and divide, making more cells.
nutrients
11. A cell gets its energy from _________________________.
multicellular
12. Organisms composed of more than one cell are called _________________________.
processes
13. Every cell can carry on the basic _________________________
of life.
similar cells
14. Tissues are made of _________________________.
tissues
15. Organs are made of _________________________.
16. Organ systems are made of _________________________
that work together.
tissues
Plant and Animal Cells
Cells are composed of many structures. The cytoplasm of the cell is the watery material in which
specialized structures are found. Each cell structure carries out a specific function.
The cell membrane separates the interior of the cell from the surrounding environment. It controls
the movement of materials into and out of the cell. The cell membrane keeps the internal conditions of the
cell constant to maintain homeostasis.
The nucleus is the control center of the cell. It controls cell metabolism and reproduction. The
nucleus contains the genetic material, DNA, which determines the inheritance of traits.
Mitochondria are the “powerhouses” of the cell. They release energy during respiration.
Vacuoles store food, water, or wastes in a cell.
Animal and plant cells have many of the same cell structures. Yet there are some differences. The
plant cell is surrounded by a rigid cell wall. It provides shape and support for the plant cell. Plant cells
have chloroplasts which contain chlorophyll. Chlorophyll is the green pigment that enables the plant to
absorb sunlight so it can produce food and oxygen by photosynthesis.
17. Complete the chart:
Cell Structure
Cytoplasm
c. nucleus
Cell membrane
Cell wall
k. chloroplast
Function
a. moves organelles
Controls cell activities,
Contains genetic material
f. controls
what goes
in and out of cell
h. shapes and
supports a plant cell
Contains chlorophyll for
photosynthesis
Animal Cell?
Yes or No
Plant Cell?
Yes or No
b. yes
Yes
d. yes
e. yes
Yes
g. yes
i. no
j. yes
l. no
m. yes
chloroplasts
18. Green plant cells contain _________________________
for photosynthesis.
plants
19. Heterotrophs obtain food by eating _________________________
and/or
animals
_________________________.
The Microscope
A microscope is an instrument used to magnify objects not visible to the naked eye such as cells.
The compound microscope has more than one lens. These are called the objectives and the eyepiece.
Images viewed under the microscope are upside down and reversed. If you move the slide to the right, it
will appear to move left under the microscope.
The area that you can see under the microscope is the field of view. The field of view is smaller
under high power than low power. Under low power, more cells or parts of an organism are seen. Under
high power, fewer cells, but more detail is seen.
The microscope can be used to observe the structure and the size of cells. Cell size can be
measured in millimeters. If you know the diameter of the field of view you can estimate the size of a cell.
microscope
20. A _________________________
is used to enlarge the appearance of cells.
lens
21. A compound microscope has more than one _________________________.
upside down
22. Images viewed under the microscope are _________________________
and
reversed
_________________________.
23. The field of view is larger for _________________________
low
power.
24. Under _________________________
power, more cells are seen.
low