Download Characteristics of Life

Characteristics of Life
(Sections 1-1 and 1-2)
Name _______________________
Date ______________ Period ____
Biology is the study of life. This worksheet will provide you with an overview of what characteristics
define something as a living thing.
1. Refer to pages 4-5. The snowy owl and the alga, Eremoophaera, appear very different. They are both
organisms, however. What is an organism?
2. Skip ahead to pages 11-13. List the 6 characteristics of all organisms.
1) ____________________________
2) ____________________________
3) ____________________________
4) ____________________________
5) ____________________________
6) ____________________________
Learn more about each characteristic by reading its short description in Section 1-2 and then referring
back to pertinent paragraphs of Section 1-1 to find more information.
Cells
3. Cells are always _________ ____________. (pg 11)
4. Refer to page 6.
a) The cell is the _____________ __________ of life.
b) What is the difference between a unicellular and multicellular organism?
c) Although there are many different kinds of cells, all cells have the same basic structure. In what
ways are all cells similar? Hint: describe 2 things.
Organization
5. Back to page 11. What are two levels of organization in organisms?
6. Refer to page 10. What sets an organism apart from an organized non-living thing, like a salt crystal?
Energy Use
7. What is metabolism? (pg 12)
8. Why do organisms require energy?
9. Refer to page 10.
a) Describe the difference between autotrophs and heterotrophs.
b) Give at least one example of each.
 Autotroph:

Heterotroph:
Homeostasis
10. All living things work to maintain ____________ ____________ _____________. (pg 12)
11. What do multicellular organisms have that help accomplish homeostasis?
12. Refer to page 6. Give an example of homeostasis in your body.
13. Carbon dioxide is a waste product produced by chemical reactions in the cells of living organisms. In
the blood the CO2 becomes carbonic acid and it lowers the pH level of the blood. Use your
understanding of homeostasis to explain why you continually breathe out carbon dioxide. Hint: think
of the definition of homeostasis and apply it. You won’t find the answer in the book!
Growth and Development
14. How do multicellular organisms grow? (pg 12)
15. You originally came from one single cell (a fertilized egg). How is it that your body is now made up
of trillions of cells that perform many different functions? Hint: describe 2 “events”.
16. Refer to page 7. A molecule called DNA is inside all cells and it directs growth and development.
The author uses the analogy that DNA is similar to a library.
a) In this analogy, what are the “books of instructions”? _______________
b) As an organism grows and develops, it produces more cells. These cells have identical DNA.
Explain, then, how your body can have many cell types that carry out different functions?
Reproduction
17. a) True or False? Reproduction is essential to the survival of an organism. (pg 13)
b) The frog pictured reproduces sexually, meaning that the offspring will carry traits of _________
parents.
18. Refer to page 7. What molecule, containing hereditary information, is passed down from parents to
offspring during reproduction? ______________