Chapter 5 Lesson 1 "Bacteria"

Materials:

• Worksheet on Bacteria Vocabulary

Objective:

• Students will describe the properties of bacteria.
• Students will explain how bacteria get energy and reproduce.
• Students will list ways in which bacteria are harmful and helpful.

Alaska Standards:

• SCI A-12 Students will distinguish the patterns of similarity and differences in the living world in order to understand the diversity of life and understand the theories that describe the importance of diversity for species and ecosystems.
• SCI A-15 Students will use science to understand and describe the local environment.
• SCI B-1 Students will use the processes of science: classifying.

Anticipatory Set: Display several pictures of nodules on roots an have the students guess the reason for the nodules.

Explain to the students that the nodules are formed by bacteria which need the plant to survive. In turn they produce a by-product of nitrogen which the plant needs to survive. This is called mutualism.

Teacher Input: Students will take out thier card on Bacteria and describe its properties while the teacher types or writes the properties on a word document.

Properties of a Bacteria: no nucleus, very small, cells lack organelles, appeared 3.5 billion years ago, classified by shape, called Prokaryotes, (no nucleus), some respond to harsh conditions by forming endospores (survive for centuries). How long is 3.5 billion years? (If a penny represented a year and they were stacked on one another 3.5 billion pennies would be 3,500 miles high.

Show the students the three main shapes of bacteria, See Page 86. Have the students describe the shape and name the type. Here is a picture to use:

Students will discuss the Did you Know on Page 86. How hot is 110 degrees Celcius?

Teacher Modeling: Have the students name three ways bacteria get energy: eg. animal waste, break down minerals, sunlight, ... Ask students how oxygen affects bacteria? (some need it to survive others are killed by it) Why do stagnant lakes with little oxygen smell? (Some bacteria that can break down materials without oxygen produce methane gas in the process) Does it take a male and female bacteria to reproduce? (no, bacteria reproduce using binary fission.

Define methane and binary fission.

Check for Understanding: Students will help develop a list of how bacteria are helpful and how they are harmful for help they may use pages 87-88 in their books.

While doing that students will define: saprophytes, mutualism, commensalism, toxin, and endospores.

Students will dicuss how refrigeration plays a role in bacteria control.

Guided Practice: Students will try to explain the difference between antibiotic and antibody. Using the chicken pox antibody and the penicillin to explain the difference between the two. Students will develop a list of 10 antibiotics.

Closure: Students will have a chance for 2 points extra credit that will go toward any test, quiz, or investigation they like. All they have to do is answer the question? Who figured out that penicillin from a mold growing in their lab is an antibiotic?

Independent Practice: Before taking the quiz have the students complete the Workbook Activity on the vocabulary for this section.

Duration:

30 minutes + 10-15 for Independent Practice (Could be longer if taken for homework).