single cell organisms

Objective 7. L.1:

Understand the processes, structures and functions of living

organisms that enable them tosurvive, reproduce and carry out

the basic functions of life.

Clarifying Objective:• 7.L.1.1 Compare the structures

and life functions of single-celled organisms that carry out all of the basic functions of life including: Euglena; Amoeba; Paramecium; Volvox.

Language Objective: 7.L.1.1 Students Will Be Able To:

Define and explain the following terms:

-Euglena -Amoeba-Paramecium -Volvox-Protists -Flagellum

-Cytoplasmic streaming-Cilia -Chlorophyll

(You)

Language Function• 7.L.1.1 SWBAT DESCRIBE AND

COMPARE the structures and functions of single celled organisms. (Euglena, Amoeba, Paramecium, and Volvox)

Language Skills7.L.1.1 SWBAT DISCUSS how single celled organisms are similar and how they vary, based on their structures and functions.

Language Structures7.L.1.1 SWBAT USE CORRECT SENTENCE FORMATION to describe the similarities and differences between single celled organisms. (Euglena, Amoeba, Paramecium, and Volvox)

Lesson Tasks7.L.1.1 SWBAT DRAW PICTURES of single celled organisms and DRAFT SENTENCES about their life functions. (Foldables)

Essential Question: What are the characteristics of the

following single-celled organisms?

EuglenaAmoeba

ParameciumVolvox

Comparisons of Single-celled Organisms

The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing (except virus, which consists only from DNA/RNA covered by protein and lipids), and is often called the building block of life

Euglena

• Found in calm fresh and salt water• Used as a model organism in the lab• Contain chloroplasts (Chloroplasts are organelles found in plant cells and other

eukaryotic organisms that conduct photosynthesis.)

• Autotrophs – get energy via photosynthesis• Can also get nourishment heterotrophically like

animals (heterotrophically is an organism that cannot synthesize its own food and is dependent on complex organic substances for nutrition.)

Euglena

• Have features of both plants and animals > Kingdom Protista

• Heterotrophic feeding – surrounds particle of food• Autotrophic feeding produces sugars via

photosynthesis where sufficient sunlight is present• Possess a red eyespot which filters sunlight and

allows the Euglena to find and move towards light

Euglena

• Does not contain a cell wall• May form a protective barrier and become

dormant until environmental conditions are more favorable

• Moves by use of a flagella

• http://www.youtube.com/playlist?list=PLMWvLl-qJ8mb1maLoPUtppQJkUCFl9FA7

Amoeba

• Can change its shape• Live in fresh and salt water, in soil, and as

parasites in moist body parts of animals• Heterotroph• One large pseudopod on back end, and

several smaller ones branching to the sides

Amoeba• Eukaryotic – contains one or more nuclei• Dines on bacteria, algae, and other protozoa• Food is enveloped, stored, and digested in

vacuoles• Reproduce asexually (mitosis and cytokinesis)

(Mitosis is the process by which a eukaryotic cell separates the chromosomes in its cell nucleus into two identical sets, in two separate nuclei.) {During Cytokinesis, the cytoplasm (the liquid center of the cell that holds the organelles into place.) splits into two equal halves, a cleavage point appears and the cell becomes two daughter cells.}

• Can survive being forcibly divided – the part with the nucleus survives, other part dies

Amoeba• May become dormant by forming into a ball and

secreting a protective membrane to survive harsh environments

• Moves using pseudopod (false foot into which the body then flows) or by changing shape

• Feed on plankton and diatoms by engulfing them with a pseudopod, it is then enveloped, stored, and digested in vacuoles

• http://www.youtube.com/playlist?list=PLMWvLl-qJ8mYt7rgFNpzZhXm8pim1zjxW

Paramecium

• Moves via cilia and spirals through the water• Can move about 12 body lengths per second• Shape resembles a shoe’s sole• Uses an oral groove to draw food inside• Feed on bacteria and other small cells• Heterotrophic • Relatively large

Paramecium

• Very common in scums and other calm freshwater environments

• Stiff elastic membrane gives it a definite shape

• Outer membrane is covered in cilia

Paramecium• Contain two nuclae (macro and micro)• Feed on micro-organisms like bacteria, algae,

and yeasts• Uses cilia to sweep food into the cell mouth

after falling into the oral groove to eventually be enveloped in a food vacolue (A vacuole is a membrane-bound sac that plays roles in intracellular digestion and the release of cellular waste products.)

• http://www.youtube.com/playlist?list=PLMWvLl-qJ8mbRm9VWx_h5mgj8hFF5teCT

Volvox

• Type of green algae• Forms spherical colonies of up to 50,000 cells• Live in lots of freshwater habitats – ponds,

ditches, puddles, lagoons• Colonies have flagellate cells for swimming

Volvox

• Cells have eyespots which enable the colony to swim towards light

• Make food via photosynthesis• Heterotrophs• Act like one multicellular organism• Reproduce sexually or asexually

Volvox• Asexual colonies:

– Daughter colonies are held within the parent colony and have flagella directed inward

– Parent eventually disintegrates and the daughter colonies invert

• Sexually reproducing colonies:– Two gametes are produced– Male colonies release sperm– Female colonies grow a single oogamete or egg

• http://www.youtube.com/playlist?list=PLMWvLl-qJ8mbaKi29FtoRsT0zKKJbGHeP