Download Meaning of Life Packet

Name: ____________________________________ Date: __________________
CW/HW: Living vs. Non-living
Regents Biology - _____
Characteristics of life
Biology is the study of life. However, there is no simple, clear-cut definition of life. We
can list certain characteristics that living things have. Here is such a list. It is not
complete. Some of the characteristics could be described in some other way. But it is a
fairly good test for deciding whether something is alive.
1.
2.
3.
4.
5.
6.
7.
Living things grow.
Living things respond to changes in their environment.
Living things reproduce.
Living things use energy.
Living things are made up of cells.
Living things contain numerous complex chemical substances
Living things have a definite form and a limited size.
8. Living things have a limited life span; they do not live forever.
There are certainly non-living things which have one or more of these characteristics.
However, to be considered alive, a thing must show all of the characteristics in the list.
What is not living, yet has one or more characteristics of life?
From the list above, assign something that is not living to each characteristic.
Example: for # 1, buildings under construction “grow”.
1. ____________________
5. ____________________
2. ____________________
6. ____________________
3. ____________________
7. ____________________
4. ____________________
8. ____________________
Bonus: On the back of this packet, identify a non-living thing and describe how it exhibits
several of the characteristics of life listed above. You will get 1 bonus point for each
characteristic correctly attributed (with a description) to one non-living thing.
Comparing living and non-living things
In the following chart, two pairs of objects are listed. In each pair, the members have several similar
characteristics, but one is living and the other is not. For each characteristic of life, check the box if it
applies to the object at the head of the column. Otherwise, leave the box blank.
Characteristic
Grows
Responds to change in environment
Reproduces
Uses Energy
Made of living cells
Contains complex chemical
substances
Has definite form and size range
Has limited life
PAIR 1
Horse
Motorcycle
PAIR 2
Tree
Telephone
Pole
Questions
1. How many characteristics of life does a horse exhibit?
________
How many characteristics of life does a motorcycle exhibit? ________
2. Is there one characteristic of life that can be used, alone, to prove something is
living? If so, explain.
An Introduction to The Eight Life Functions: 4 R’s TENS
The biological term for a living thing is organism. From now on we will use this term to
refer to a single living thing.
Organisms show the characteristics of life that have already been mentioned. They
also carry on certain activities that are characteristic of life. These are called the life
functions (or processes), and they include the following:
Reproduction
Respiration
Repair and growth
Regulation
Transport
Excretion
Nutrition
Synthesis
The term metabolism is
used to refer to all of the
eight life functions
together.
If any of these metabolic processes except reproduction stops for any length of time, the
organism dies. If reproduction of the organism does not occur, that species (type of
organism) may die out, or become extinct. Reproduction is a process that is necessary
for the continuance of a particular life form.
Reproduction
Reproduction is the process by which organisms give rise to offspring – new
individuals of the same kind. There are two basic types of reproduction—asexual and
sexual. In asexual reproduction the new individual is identical to the parent, a clone. In
sexual reproduction, there is an exchange of hereditary material between two different
organisms, and the offspring are not identical to either parent.
Questions
1. The two basic types of reproduction are _______________ and
___________________.
2. In __________________ reproduction the offspring are clones of the parent.
3. Organisms can live without ever reproducing, why is reproduction considered a
life function? (hint: re-read the intro. to this section!)
Respiration
The process of respiration releases energy from food by a complex series of chemical
reactions. These reactions occur within all the cells of the organism. The energy
released by this process is used for the other life processes. Respiration generally
requires the presence of oxygen. While humans carry out breathing to obtain oxygen
for respiration, respiration is NOT the same as breathing. Breathing is the process by
which air is moved into and out of the lungs.
Questions
4. What is accomplished by the process of respiration?
5. What is the relationship between breathing and respiration?
6. Humans cannot live without breathing, why isn’t breathing considered a life
function?
7. Why is the process of respiration important for the other life functions?
Repair and Growth
Organisms are able to repair damaged tissue by making new cells or cell parts. Growth
is an increase in the size of an organism by increasing the size and numbers of the cells
that make it up. These processes utilize digested food substances obtained by nutrition
to synthesize (see description of synthesis on last page of this packet) new materials
and structures.
Questions
8. Two other life functions are required to carry out the life function of repair and
growth:
a) The materials for repair and growth are obtained by _________________
and, b) they are combined into new, more complex materials and structures by
____________________.
Regulation
Regulation involves a number of coordinated activities that serve to maintain
homeostasis, a stable internal environment. This is important because an organism’s
internal and external environments are constantly changing.
The two major organ systems involved in regulation are the nervous system and the
endocrine system. The nervous system is made up of specialized cells that are able to
conduct electrical impulses. The endocrine system is made up of glands whose cells
produce a variety of organic compounds called hormones. The pancreas is an
example of an endocrine gland. It produces insulin and glucagon to regulate blood
sugar levels. Both electrical impulses and hormones can stimulate responses in the
tissues and organs of the body.
Questions
9. What is the term, associated with regulation, which is used to describe an
organism’s ability to maintain a stable internal environment?
10. Give an example of when an organism’s internal environment may change.
You have to
think about
these ones!
11. Give an example of a change to an organism’s external environment.
12. What part of the human nervous system acts as the control center? __________
13. The pancreas releases chemicals (“pancreatic juices”) that are important to
digestion, but it is also considered a regulatory organ. Why?
Transport
The function of transport involves the absorption and distribution (circulation) or
essential materials throughout the organism. In one-celled and other simple organisms,
needed materials and wastes can pass directly between the environment and the cells
of the organism. In humans, blood is transported throughout the circulatory system to
carry these materials between the cells of the organism and the environment.
Questions
14. What is accomplished by the transport process?
15. In humans, digested food is transported to all the cells of the body by the
_____________________ system.
16. The liquid tissue of transport in the human body is the ___________________.
Excretion
Excretion is the function by which the wastes of metabolism are removed from the
organism. In one-celled and other simple organisms, these wastes can pass out of the
organisms directly into the environment. In more complex organisms, the wastes must
be carried away from the cells by the circulatory system and eliminated from the
organism by a specialized excretory system. In humans, the excretory system includes
the lungs for the removal of carbon dioxide and the kidneys to filter out other wastes.
Questions
17. What is excretion?
18. In humans, the organs that filter wastes from the blood are the _____________.
19. The gaseous waste removed from the lungs is ____________ _____________.
20. What other life function is associated with the removal of wastes? ____________
(hint: wastes are produced in all of the cells of the body, but there are only a few organs involved
in their removal—so the wastes need to get to them!—What life function circulates the wastes?)
Nutrition
Nutrition includes all the activities by which an organism obtains food from the
environment and digests (breaks down) the food into a form that can be absorbed and
used by its cells. These nutrients may be used for energy or to build new cells, or they
may be used to build more complex substances needed to carry out the other
characteristics of life.
Green plants, using energy from the sunlight can make their own food by the process of
photosynthesis. All animals, either directly or indirectly, depend on green plants for
food.
Questions
21. Why do living things need food?
22. What happens to food in the process of digestion?
23. Two organs of the human digestive system are the ________________ and the
________________. (you’ve got to think about this one on your own!)
24. Identify two other life functions that depend on the process of nutrition (hint: see
the underlined words above, they describe other life functions).
Synthesis
Synthesis is the process by which simple molecules are combined chemically to form
more complex molecules. Through various synthetic pathways, needed substances are
made from the body’s stores of simpler molecules. Also, through these pathways one
type of compound can be changed into another. Think of it this way: you eat a
hamburger as a source of protein, but you do not need the same proteins the cow had,
so you first digest that protein into smaller components (amino acids) that you can use
to build your own proteins with.
Questions
25. The process by which simple molecules combine to form more complex
molecules is ____________________.
26. What other life function (besides synthesis) are plants performing when they do
“photosynthesis” (Hint: this is how they get their food)?
In conclusion,
1. What is the term for all of the eight life functions all living things MUST carry out?
2. What is the only life function an organism can live without, and why do we call it a life
function?
3. List the eight life functions below.