Name:__________________________________ Date ...



Name:__________________________________ Date:___________________ Period:___________

|Unicellular Organisms |   |[pic] |

|By Cindy Grigg | | |

[pic]

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

[pic]

|1.   |2.   |

|What are unicellular organisms? |What does unicellular mean? |

|[pic]  Animals with many cells |[pic]  Unicycle |

|[pic]  Plants with many cells |[pic]  One cell |

|[pic]  Not alive |[pic]  Many cells |

|[pic]  Plants, animals, fungi, or bacteria made of only one cell |[pic]  Multicellular |

| | |

|3.   |4.   |

|How long do scientists think unicellular organisms have lived on Earth? |What is the advantage of having a spherical shape? |

|[pic]  3.8 trillion years |[pic]  Easier to move |

|[pic]  3.8 million years |[pic]  Keeps it from drying out |

|[pic]  Millions of years |[pic]  More surface area for chemical exchanges with the environment |

|[pic]  3.8 billion years |[pic]  Can get more food |

| | |

|5.   |6.   |

|What is the advantage of having a spiral shape? |Where have extremophiles been found? |

|[pic]  Can get more food |[pic]  On the moon |

|[pic]  Easier to move |[pic]  On Mars and Europa |

|[pic]  More surface area for chemical exchanges with the environment |[pic]  In Antarctica and the deep sea |

|[pic]  Keeps it from drying out |[pic]  On the sun |

| | |

|7.   |8.   |

|What is one kind of unicellular organism that is helpful to people? |What does pseudopodia mean? |

|[pic]  Paramecium |[pic]  False name |

|[pic]  Euglena |[pic]  Encyclopedia |

|[pic]  Yeast |[pic]  Made-up name |

|[pic]  Amoeba |[pic]  False feet |

| | |

 

|Name _____________________________ | |[pic] |Date ___________________ |

Unicellular Organisms

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

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|Unicellular Organisms |   |[pic] |

|By Cindy Grigg | | |

[pic]

| | | |

| |digest | |

| |support | |

| |oblong | |

| |hair-like | |

| | | |

| | | |

| | | |

| |adaptation | |

| |billion | |

| |invisible | |

| |drying | |

| | | |

| | | |

| | | |

| |visible | |

| |sensitive | |

| |form | |

| |engulf | |

| | | |

| | | |

| | | |

| |ability | |

| |particularly | |

| |eventually | |

| | | |

| | | |

| | | |

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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!

[pic]

Copyright © 2006 edHelper

 

|Name _____________________________ | |[pic] |Date ___________________ |

Unicellular Organisms

|1.   |2.   |

|What are unicellular organisms? |What does unicellular mean? |

|[pic]  Plants with many cells |[pic]  One cell |

|[pic]  Animals with many cells |[pic]  Unicycle |

|[pic]  Plants, animals, fungi, or bacteria made of only one cell |[pic]  Multicellular |

|[pic]  Not alive |[pic]  Many cells |

| | |

|3.   |4.   |

|How long do scientists think unicellular organisms have lived on Earth? |What is the advantage of having a spherical shape? |

|[pic]  3.8 billion years |[pic]  Easier to move |

|[pic]  3.8 million years |[pic]  Can get more food |

|[pic]  3.8 trillion years |[pic]  Keeps it from drying out |

|[pic]  Millions of years |[pic]  More surface area for chemical exchanges with the environment |

| | |

|5.   |6.   |

|What is the advantage of having a spiral shape? |Where have extremophiles been found? |

|[pic]  Easier to move |[pic]  In Antarctica and the deep sea |

|[pic]  Keeps it from drying out |[pic]  On the sun |

|[pic]  More surface area for chemical exchanges with the environment |[pic]  On the moon |

|[pic]  Can get more food |[pic]  On Mars and Europa |

| | |

|7.   |8.   |

|What is one kind of unicellular organism that is helpful to people? |What does pseudopodia mean? |

|[pic]  Paramecium |[pic]  Encyclopedia |

|[pic]  Euglena |[pic]  Made-up name |

|[pic]  Yeast |[pic]  False name |

|[pic]  Amoeba |[pic]  False feet |

| | |

 

|Name _____________________________ | |[pic] |Date ___________________ |

| | | |(Key 1 - Answer ID # 1070361) |

Find each of the following words.

| |

| |

| |

|DEEP-SEA |

| |

|SURVIVAL |

| |

|VISIBLE |

| |

|ENGULF |

| |

| |

|SENSITIVE |

| |

|HOSTILE |

| |

|EXTREMELY |

| |

|NAKED |

| |

| |

|FORM |

| |

|HARMFUL |

| |

|ABILITY |

| |

|DIVERSIFY |

| |

| |

|INVISIBLE |

| |

|OBLONG |

| |

|INGENIOUS |

| |

|CHEMICAL |

| |

| |

| |

|I |

1  [pic]  Plants, animals, fungi, or bacteria made of only one cell

2  [pic]  One cell

3  [pic]  3.8 billion years

4  [pic]  Keeps it from drying out

5  [pic]  Easier to move

6  [pic]  In Antarctica and the deep sea

7  [pic]  Yeast

8  [pic]  False feet

 

|Unicellular Organisms |   |[pic] |

|By Cindy Grigg | | |

|Answer Key |

[pic]

     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!

[pic]

Answers to Reading Comprehension Questions

1  [pic]  Plants, animals, fungi, or bacteria made of only one cell

2  [pic]  One cell

3  [pic]  3.8 billion years

4  [pic]  Keeps it from drying out

5  [pic]  Easier to move

6  [pic]  In Antarctica and the deep sea

7  [pic]  Yeast

8  [pic]  False feet

 

|Answer Key 1070361 |

|Key # 1 |

|DEEP-SEA |SURVIVAL |VISIBLE |ENGULF |

|SENSITIVE |HOSTILE |EXTREMELY |NAKED |

|FORM |HARMFUL |ABILITY |DIVERSIFY |

|INVISIBLE |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 |  |  |  |  |  |  |  |  |  |  |  |  |  |  | |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | |

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