Biology Guides SS 1 Continuity of Life – Reproduction in Unicellular Organisms and Invertebrates

BIOLOGY 

THEME – CONTINUITY OF LIFE 

TOPIC – REPRODUCTION IN UNICELLULAR ORGANISMS AND INVERTEBRATES

INSTRUCTIONAL MATERIALS

1. Prepared microscope slides of conjugation in spirogyra, microscope slides, torch light.

2. Charts illustrating binary and multiple fission.

3. Chart showing stages of metamorphosis in cockroach.

4. Eggs of cockroach.

5. Maggots from housefly.

6. Snail eggs.

7. Charts showing complete and incomplete metamorphosis.

8. Cardboard sheets.

9. Markers

10. Containers

LEARNING OBJECTIVES

By the end of the lesson, students should be able to:

1. describe reproduction in,

• Amoeba

• Paramecium

• Spirogyra

2. describe reproduction in,

• Earthworm

• Cockroach

• Housefly

• Snail

3. differentiate between complete and incomplete metamorphosis.

CONTENTS OF THE LESSON

FOCUS LESSONS 

1. Reproduction in amoeba by asexual reproduction,

• binary fission

• multiple fission

2. Reproduction in paramecium by,

• asexual reproduction

• sexual reproduction

3. Reproduction in Spirogyra by,

• asexual or vegetative reproduction

• sexual reproduction or conjugation

4. Reproduction in the Earthworm – sexual reproduction only

5. Reproduction in Cockroach,

• fertilization is internal

• exhibits incomplete metamorphosis

6. Reproduction in housefly,

• fertilization is internal

• exhibits complete metamorphosis

7. Reproduction in the Snail,

• fertilization is internal

• lay eggs which hatch into young snails

LESSON PRESENTATION

TEACHER’S ACTIVITIES

The teacher to,

1. Mount specimens from the ditch on the microscope for students to observe.

2. Request students to collect eggs of cockroaches and observe.

3. Collect maggots of housefly and keep for observations.

4. Collect eggs laid by a snail and keep in a closed container for observation.

5. Collect some earthworms and keep in a suitable container for students to observe.

 

STUDENT’S ACTIVITIES

The students to,

1. Collect water from the ditch and view under the microscope to observe unicellular organisms.

2. Observe prepared slides of their reproductive stages.

3. Watch earthworm at night with a torch light.

4. Observe the collected cockroach eggs and note your observations.

5. Observe the housefly maggots daily and note your observations

6. Observe the snail eggs and take daily notes.

7. Prepare a chart to show complete metamorphosis.

 

LESSON EVALUATION

Students to,

1. define asexual and sexual reproduction.

2. describe the two major ways by which spirogyra and paramecium reproduce.

3. describe the mode of reproduction found in the earthworm.

4. why is the cockroach said to exhibit incomplete metamorphosis?

5. distinguish between complete and incomplete metamorphosis.

6. what is the major difference in the life cycle of a cockroach and a housefly?

7. what is the main feature of reproduction in snail?