Name:__________________________________ Date:___________________ Period:___________

Unicellular Organisms By Cindy Grigg

  

1     You know that living things are made of cells. Some animals and plants are made of only one cell. They are called unicellular. Uni- means one as a unicycle has only one wheel. Most of us don't think about these unicellular creatures very much, but they are all around us. Most are invisible without a microscope, but a few may be visible to the naked eye. 2     The main groups of unicellular organisms are bacteria, protozoa, unicellular algae, and unicellular fungi or yeasts. Each species is unique, and they are interesting to study because of their complex and beautiful patterns. Some unicellular organisms are sensitive to light. They may move toward it or away from it, and they have ingenious ways of moving around. They also respond to touch. Some can live in very hostile environments. 3     Single-celled organisms have been on earth for perhaps 3.8 billion years, so they have had a long time in which to diversify. Scientists believe they were the first life-forms on Earth. Although small, they are complex. They have ancient and effective means of survival. The more that we learn about them, the more amazing we find them to be. 4     Some of their survival mechanisms have to do with their shapes. They may be spheres, oblong, or spiral. A spherical shape resists drying out, something that would be fatal to a cell. An oblong shape gives the cell more surface area for chemical exchanges with its environment. A spiral shape makes it easier for the organism to move. 5     Unicellular organisms have unique ways to move. Some, such as euglena, have tiny hair-like fibers that are called flagella. These fibers thrash in the water and drive the cell forward. The word flagellum means whip in Latin. Flagella (pronounced fla-jell-ah) is the plural form. Some have groups or rows of tiny fibers that move together like oars in a sort of rippling pattern. These are called cilia (pronounced silly-ah). Cells with cilia move fast! A paramecium is one unicellular organism that moves with cilia. 6     Some unicellular organisms called amoebas are able to change their shapes. These "shape-shifters" can extend parts of themselves into what are called pseudopodia and then flow in the direction in which they wish to go. Pseudopodia (pronounced sue-do-pode-ee-ah) means false feet. If they find something to eat, they can engulf, or surround, the particle with their pseudopodia. Then they pull themselves around it to digest it. 7     Just as the amoeba uses its pseudopodia both for movement and feeding, some unicellular organisms with cilia also use the cilia to catch food. The stentor has cilia that beat rhythmically, which draws food into its mouth. This is an adaptation that allows stentors to spend most of their lives attached to a surface, saving their energy for catching food. 8     Some unicellular organisms live in extreme environments. Archaebacteria that like living in such challenging places are called extremophiles(_______________________). They have been found in such unfriendly habitats as Antarctic ice and in very hot deep-sea vents. The ability of organisms to adapt to extremely hot or cold environments gives scientists hope that signs of life will eventually be found on other planets. They have targeted Mars and Europa, an icy moon of Jupiter, as perhaps having conditions that could support some sort of living thing.

 

9     People use yeast, one kind of unicellular organism, to make bread and beer. Others are helpful because they eat harmful bacteria and are food for fish and other animals. At least one kind of unicellular organism can cause illness in people. Amoebic dysentery, whose main symptom is bloody diarrhea, is transmitted by water containing one type of amoeba. It is well known as traveler's dysentery, or Montezuma's Revenge, particularly in Mexico. Liver infection and abscesses can occur also. It can be treated with antibiotic drugs. 10     Unicellular organisms are all around us. They have lived on Earth for many millions of years and have developed unique ways to survive. Although small, they are complex and beautiful. The next time you look at pond water, just think what you might discover there!

Copyright © 2006 edHelper

1.   What are unicellular organisms?  Animals with many cells  Plants with many cells  Not alive  Plants, animals, fungi, or bacteria

made of only one cell

2.   What does unicellular mean?  Unicycle  One cell  Many cells  Multicellular

3.   How long do scientists think unicellular organisms have lived on Earth?

  3.8 trillion years  3.8 million years  Millions of years  3.8 billion years

4.   What is the advantage of having a spherical shape?

  Easier to move  Keeps it from drying out  More surface area for chemical

exchanges with the environment  Can get more food

5.   What is the advantage of having a spiral shape?

  Can get more food  Easier to move  More surface area for chemical

exchanges with the environment  Keeps it from drying out

6.   Where have extremophiles been found?  On the moon

  On Mars and Europa  In Antarctica and the deep sea  On the sun

7.   What is one kind of unicellular organism that is helpful to people?

  Paramecium  Euglena  Yeast  Amoeba

8.   What does pseudopodia mean?  False name  Encyclopedia  Made-up name  False feet

 

Name _____________________________ Date ___________________

Unicellular OrganismsWhat are the differences between unicellular and multicellular organisms? Include as many details as you can.

 

Unicellular Organisms By Cindy Grigg

  

digest support oblong hair-likeadaptation billion invisible dryingvisible sensitive form engulfability particularly eventually

Directions:  Fill in each blank with the word that best completes the reading comprehension.

     You know that living things are made of cells. Some animals and plants are made of only one cell. They are called unicellular. Uni- means one as a unicycle has only one wheel. Most of us don't think about these unicellular creatures very much, but they are all around us. Most are (1)  _______________________   without a microscope, but a few may be (2)  _______________________   to the naked eye.     The main groups of unicellular organisms are bacteria, protozoa, unicellular algae, and unicellular fungi or yeasts. Each species is unique, and they are interesting to study because of their complex and beautiful patterns. Some unicellular organisms are (3)  _______________________   to light. They may move toward it or away from it, and they have ingenious ways of moving around. They also respond to touch. Some can live in very hostile environments.     Single-celled organisms have been on earth for perhaps 3.8 (4)  _______________________   years, so they have had a long time in which to diversify. Scientists believe they were the first life-forms on Earth. Although small, they are complex. They have ancient and effective means of survival. The more that we learn about them, the more amazing we find them to be.     Some of their survival mechanisms have to do with their shapes. They may be spheres, oblong, or spiral. A spherical shape resists (5)  _______________________   out, something that would be fatal to a cell. An (6)  _______________________   shape gives the cell more surface area for chemical exchanges with its environment. A spiral shape makes it easier for the organism to move.     Unicellular organisms have unique ways to move. Some, such as euglena, have tiny (7)  _______________________   fibers that are called flagella. These fibers thrash in the water and drive the cell forward. The word flagellum means whip in Latin. Flagella (pronounced fla-jell-ah) is the plural (8)  _______________________  . Some have groups or rows of tiny fibers that move together like oars in a sort of rippling pattern. These are called cilia (pronounced silly-ah). Cells with cilia move fast! A paramecium is one unicellular organism that moves with cilia.     Some unicellular organisms called amoebas are able to change their shapes. These "shape-shifters" can extend parts of themselves into what are called pseudopodia and then flow in the direction in which they wish to go. Pseudopodia (pronounced sue-do-pode-ee-ah) means false feet. If they find something to eat, they can (9)  _______________________  , or surround, the particle with their pseudopodia. Then they pull themselves around it to (10)  _______________________   it.     Just as the amoeba uses its pseudopodia both for movement and feeding, some unicellular organisms with cilia also use the cilia to catch food. The stentor has cilia that beat rhythmically, which draws food into its mouth. This is an (11)  _______________________   that allows

stentors to spend most of their lives attached to a surface, saving their energy for catching food.     Some unicellular organisms live in extreme environments. Critters that like living in such challenging places are called extremophiles. They have been found in such unfriendly habitats as Antarctic ice and in very hot deep-sea vents. The (12)  _______________________   of organisms to adapt to extremely hot or cold environments gives scientists hope that signs of life will (13)  _______________________   be found on other planets. They have targeted Mars and Europa, an icy moon of Jupiter, as perhaps having conditions that could (14)  _______________________   some sort of living thing.     People use yeast, one kind of unicellular organism, to make bread and beer. Others are helpful because they eat harmful bacteria and are food for fish and other animals. At least one kind of unicellular organism can cause illness in people. Amoebic dysentery, whose main symptom is bloody diarrhea, is transmitted by water containing one type of amoeba. It is well known as traveler's dysentery, or Montezuma's Revenge, (15)  _______________________   in Mexico. Liver infection and abscesses can occur also. It can be treated with antibiotic drugs.     Unicellular organisms are all around us. They have lived on Earth for many millions of years and have developed unique ways to survive. Although small, they are complex and beautiful. The next time you look at pond water, just think what you might discover there!

Copyright © 2006 edHelper

 

Name _____________________________ Date ___________________

Unicellular Organisms

1.   What are unicellular organisms?  Plants with many cells  Animals with many cells  Plants, animals, fungi, or bacteria

made of only one cell  Not alive

2.   What does unicellular mean?  One cell  Unicycle  Multicellular  Many cells

3.   How long do scientists think unicellular organisms have lived on Earth?

  3.8 billion years  3.8 million years  3.8 trillion years  Millions of years

4.   What is the advantage of having a spherical shape?

  Easier to move  Can get more food  Keeps it from drying out  More surface area for chemical

exchanges with the environment

5.   What is the advantage of having a spiral shape?

  Easier to move  Keeps it from drying out  More surface area for chemical

exchanges with the environment  Can get more food

6.   Where have extremophiles been found?  In Antarctica and the deep sea  On the sun  On the moon  On Mars and Europa

7.   What is one kind of unicellular organism that is helpful to people?

  Paramecium  Euglena  Yeast  Amoeba

8.   What does pseudopodia mean?  Encyclopedia  Made-up name  False name  False feet

 

Name _____________________________ Date ___________________ (Key 1 - Answer ID # 1070361)

Find each of the following words.

DEEP-SEASURVIVALVISIBLEENGULF

SENSITIVEHOSTILEEXTREMELYNAKED

FORMHARMFULABILITYDIVERSIFY

INVISIBLEOBLONGINGENIOUSCHEMICAL

I L B M N P R S O I T B X G N O L B O O A F S U I EB S I L W S L F N A K E D H X H N R S E I Y L A L VV - V N T A O I E S C I F R E N P A S I E A N V A TF O R M H U F X Y F I S R E V I D - I O A N S V O DN S E N S I T I V E R R A S I I P I V T I E X S T LF I Y T I L I B A S H E S H S E I H I N L - R E F RE L E R K E H M U H K U H E E N H E T E R S E E L LI S U A N E E E M I E B X D G A S I I L I V I E U N

M B E G D I N O B L A N G E S O I V S B N L I T G VS R L L N E A S I S N S N T I C E B N I V U D H N NB I S U B A E T G K N I I H N I E T E S I X V U E ER N O O O E S P M V O L A U I S A G S I S E R L X RY L N L S O S D - U E R E H A M F U L V I E L H T VE V V B H U E I S S M L H U V I I V U S B B E I R IT E I I D B R T V F A S U I O N E G N I L I I B E TR L M S S U S V U N L E L L U E E M F C E I C U M II S E I A R K L I I I Y F E S R E V I D A I I L E FL B A V M L R Y S V R E A E F N C H E M I C A L L XV E S R M E N S A H A C U E X T E M E L Y I B M Y LE T M E O I R E U N B L S T L V H V N E C C I V G LN I E H A M V N T E A L I V E V C I N U I M Y I V G

 

Unicellular Organisms - Answer Key1     Plants, animals, fungi, or bacteria made of only one cell2     One cell3     3.8 billion years4     Keeps it from drying out5     Easier to move6     In Antarctica and the deep sea7     Yeast8     False feet

 

Unicellular OrganismsBy Cindy Grigg

  

Answer Key

     You know that living things are made of cells. Some animals and plants are made of only one cell. They are called unicellular. Uni- means one as a unicycle has only one wheel. Most of us don't think about these unicellular creatures very much, but they are all around us. Most are (1)  invisible   without a microscope, but a few may be (2)  visible   to the naked eye.     The main groups of unicellular organisms are bacteria, protozoa, unicellular algae, and unicellular fungi or yeasts. Each species is unique, and they are interesting to study because of their complex and beautiful patterns. Some unicellular organisms are (3)  sensitive   to light. They may move toward it or away from it, and they have ingenious ways of moving around. They also respond to touch. Some can live in very hostile environments.     Single-celled organisms have been on earth for perhaps 3.8 (4)  billion   years, so they have had a long time in which to diversify. Scientists believe they were the first life-forms on Earth. Although small, they are complex. They have ancient and effective means of survival. The more that we learn about them, the more amazing we find them to be.     Some of their survival mechanisms have to do with their shapes. They may be spheres, oblong, or spiral. A spherical shape resists (5)  drying   out, something that would be fatal to a cell. An (6)  oblong   shape gives the cell more surface area for chemical exchanges with its environment. A spiral shape makes it easier for the organism to move.     Unicellular organisms have unique ways to move. Some, such as euglena, have tiny (7)  hair-like   fibers that are called flagella. These fibers thrash in the water and drive the cell forward. The word flagellum means whip in Latin. Flagella (pronounced fla-jell-ah) is the plural (8)  form  . Some have groups or rows of tiny fibers that move together like oars in a sort of rippling pattern. These are called cilia (pronounced silly-ah). Cells with cilia move fast! A paramecium is one unicellular organism that moves with cilia.     Some unicellular organisms called amoebas are able to change their shapes. These "shape-shifters" can extend parts of themselves into what are called pseudopodia and then flow in the direction in which they wish to go. Pseudopodia (pronounced sue-do-pode-ee-ah) means false feet. If they find something to eat, they can (9)  engulf  , or surround, the particle with their pseudopodia. Then they pull themselves around it to (10)  digest   it.     Just as the amoeba uses its pseudopodia both for movement and feeding, some unicellular organisms with cilia also use the cilia to catch food. The stentor has cilia that beat rhythmically, which draws food into its mouth. This is an (11)  adaptation   that allows stentors to spend most of their lives attached to a surface, saving their energy for catching food.     Some unicellular organisms live in extreme environments. Critters that like living in such challenging places are called extremophiles. They have been found in such unfriendly habitats as Antarctic ice and in very hot deep-sea vents. The (12)  ability   of organisms to adapt to extremely hot or cold environments gives scientists hope that signs of life will (13)  eventually   be found on other planets. They have targeted Mars and Europa, an icy moon of Jupiter, as perhaps having conditions that could (14)  support   some sort of living thing.     People use yeast, one kind of unicellular organism, to make bread and beer. Others are helpful because they eat harmful bacteria and are food for fish and other animals. At least one kind of unicellular organism can cause illness in people. Amoebic dysentery, whose main symptom is bloody diarrhea, is transmitted by water containing one type of amoeba. It is well known as traveler's dysentery, or Montezuma's Revenge, (15)  particularly   in Mexico. Liver

infection and abscesses can occur also. It can be treated with antibiotic drugs.     Unicellular organisms are all around us. They have lived on Earth for many millions of years and have developed unique ways to survive. Although small, they are complex and beautiful. The next time you look at pond water, just think what you might discover there!

Answers to Reading Comprehension Questions

1     Plants, animals, fungi, or bacteria made of only one cell2     One cell3     3.8 billion years4     Keeps it from drying out5     Easier to move6     In Antarctica and the deep sea7     Yeast8     False feet

 

Answer Key 1070361Key # 1

DEEP-SEA SURVIVAL VISIBLE ENGULFSENSITIVE HOSTILE EXTREMELY NAKEDFORM HARMFUL ABILITY DIVERSIFYINVISIBLE OBLONG INGENIOUS CHEMICAL

                          G N O L B O   A                          N A K E D             E                                                S              F O R M         Y F I S R E V I D -                  S E N S I T I V E             P                      Y T I L I B A             E I               F                              E N       E         L                      E     D G         L I       U                    L       E           B N       G                  I       N             I V       N                T       I   H           S I       E              S       O   A             I S       X          S O       U   R               V I       T          H U     S   M                   B       R              R     F                     L       E                V U                       E       M                L I                               E                    V             C H E M I C A L L                      A                           Y                        L