Teacher Notes

Teacher Notes

This lesson is an inquiry-based lesson on the factors that affect the germination of seeds. It is prepared with the 4E learning Cycle model. The lesson needs a number of days to fully cycle through the phases of inquiry.

Topic: The factors for the germination and survival of plants.

National Standard addressed by the Lesson

CONTENT STANDARD A: Science Inquiry. As a result of activities in grades K-4, all students should develop abilities necessary to do scientific inquiry.

CONTENT STANDARD C: K-4

As a result of activities in grades K-4, all students should develop understanding of

The characteristics of organisms
Life cycles of organisms
Organisms and environments

CONTENT STANDARD C: 5-8

As a result of their activities in grades 5-8, all students should develop understanding of Structure and function in living systems

Missouri Grade Level Expectations addressed by Lesson.

Science Strand 3.1 (A) b. Identify the basic needs of most plants (i.e., air, water, light) (A)c Predict and investigate the growth of plants when growing conditions are altered (e.g., dark vs. light, water vs. no water)

Objectives: Students will develop the abilities to

1) describe germination.

2) describe and test factors that affect germination.

3) describe factors that do not affect germination.

Concept : This lesson is about factors that affect the germination of seeds. It is designed to guide students to investigate the factors necessary for germination and other factors that do not affect the germination of seeds. The lesson is also an exercise in scientific inquiry.

During this lesson students develop an understanding of germination and the factors that influence it. In germination–the growth of a young plant from a seed–the plant embryo resumes growth after a period of dormancy. Seeds need oxygen, water, and proper temperatures to germinate.

There are other factors that may affect the germination of seeds. Some seeds need their tough seed coats altered to become penetrable by water. This natural process is simulated through the agriculture technique of scarification.

Concept Exploration/Engagement Phase: To begin the class, teacher displays a radish plant with a bright red radish. A radish plant is chosen for this exercise because of the short time it requires to grow and produce fruit. Through questioning teacher creates interest and curiosity about how radishes grow, and how quickly radishes can be produced. Questions like - Who can tell us what this is? Where did it come from? You should expect various answers as to where radishes come from, from seeds, from trees, etc. Other questions could be: Do plants grow better in the dark or in the light? Do plants grow better with or without water? With or without fertilizers? Allow students to discuss freely. Tell students that these issues will be investigated during this exercise.

Now divide the class into groups of two or three students and distribute student handouts. A group will be the control group that will carry out the control experiment.

Activities:

During this stage students will plant radish seeds. Each group will investigate one of the factors that affect or do not affect germination. A group may choose to plant some seeds in a petri dish but not add water, another group may choose to add fertilizer, another may add every nutrient but put their petri dish in the dark. The control group will plant radish seeds with all natural factors present, except fertilizer. Students record their data after a couple of days later.

Data Table:

Group	# of Seeds Germinated Control group	# of seeds Germinated Treatment group	Treatment
1
2
3
4
5
6
7
8

Explanation Phase:

This phase begins with each group presenting their findings to the class. Each group will discuss what they investigated, their experiments and their findings. The conversation at this stage becomes more content specific. Functional vocabularies are introduced as conclusions are drawn from students findings.

Application Phase:

In this phase students get the opportunity to investigate other factors affecting germination. Students are to plant radishes using fertilizers from stores with different chemical contents, and report on which fertilizer works best with radishes. The teacher guidance in choosing a fertilizer is important. The teacher should bring these various brands to school and have students plant a small garden in school.

Table to Record Data

Fertilizer Brand	Effect on germination
1
2
3
4
5

Materials List:

	6 polystyrene petri dishes
	Masking tape or wax pen to label petri dishes
	Absorbent paper such as paper towels, coffee filters, or filter paper
	Beaker with water
	Eyedropper
	Approximately 100 radish seeds
	Scissors (if absorbent paper needs to be cut)

Historical perspectives:

Factors that influence planting good crop reap have preoccupied farmers and scientists for centuries. Many kinds of seeds have very thick seed coats that require quite some amount of water to loosen the coats and allow sprouting to take place. This fact has been known for generations. Hence rain forests have thicker vegetation than the desert with little or no rain.

References:

Lee, A. Cherin, (2003). A learnng Cycle Inquiry into Plant Nutrition. The American Biology Teacher, 65, 136-141

Douglas Llewellyn. (2002) Inquire Within, Implementing Inquiry-Based Science Standards

http://unr.edu/homepage/crowther/ejse/rillero.html

http://koning.ecsu.ctstateu.edu/seedg/seed.html