Reproduction in Unicellular Organisms and Invertebrates | Asexual and Sexual Reproduction | Reproduction in Amoeba Paramecium Spirogyra | Differentiate between Complete and Incomplete Metamorphosis SS 1 – Biology
CONTINUITY OF LIFE
SENIOR SECONDARY SCHOOL (SSS 1)
TOPIC – REPRODUCTION IN UNICELLULAR ORGANISMS AND INVERTEBRATES
2. Asexual and Sexual Reproduction
3. Reproduction in Amoeba
4. Reproduction in Paramecium
5. Reproduction in Spirogyra
6. Reproduction in the Earthworm
7. Reproduction in Cockroach
8. Reproduction in Housefly
9. Reproduction in the Snail
By the end of the lesson, most of the students should have attained the following objectives –
1. describe reproduction in
2. describe reproduction in-
3. differentiate between complete and incomplete metamorphosis.
The teacher will teach the lesson with the aid of:
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.
METHOD OF TEACHING
Choose a suitable and appropriate methods for the lessons.
Note – Irrespective of choosing methods of teaching, always introduce an activities that will arouse pupil’s interest or lead them to the lessons.
1. Scheme of Work
2. National Curriculum for SSS Classes
3. Course Book
4. All Relevant Material
5. Online Information
CONTENT OF THE LESSON
Reproduction is the process by which adult animals reproduce their young ones.
Reproduction is one of the characteristics of living things.
There are two basic types of reproduction –
1. asexual reproduction
2. sexual reproduction.
Asexual and sexual reproduction, two methods of reproduction among living things, produce their young ones are genetically unique.
MEANING OF ASEXUAL REPRODUCTION
Asexual reproduction involves a single parent.
Asexual reproduction includes fission, budding, fragmentation, and parthenogenesis.
- binary fission: the process whereby a cell divides asexually to produce two daughter cells.
- hermaphroditism: having sexual organs of both sexes.
- parthenogenesis: a form of asexual reproduction where growth and development of embryos occur without fertilization
Reference – bio.libretexts.org
MEANING OF SEXUAL REPRODUCTION
Sexual reproduction involves two parents.
Sexual reproduction is possible through the combination of reproductive cells from two parents.
REPRODUCTION IN AMOEBA BY ASEXUAL REPRODUCTION
1. BINARY FISSION
2. MULTIPLE FISSION
REPRODUCTION IN PARAMECIUM BY
1. ASEXUAL REPRODUCTION
2. SEXUAL REPRODUCTION
REPRODUCTION IN SPIROGYRA BY
1. ASEXUAL OR VEGETATIVE REPRODUCTION
2. SEXUAL REPRODUCTION OR CONJUGATION
REPRODUCTION IN THE EARTHWORM
SEXUAL REPRODUCTION ONLY
REPRODUCTION IN COCKROACH
1. FERTILIZATION IS INTERNAL
2. EXHIBITS INCOMPLETE METAMORPHOSIS
REPRODUCTION IN HOUSE FLY
FERTILIZATION IS INTERNAL
EXHIBITS 6COMPLETE METAMORPHOSIS
REPRODUCTION IN THE SNAIL
FERTILIZATION IS INTERNAL
LAY EGGS WHICH HATCH INTO young SNAILS
To deliver the lesson, the teacher adopts the following steps:
1. To introduce the lesson, the teacher revises the previous lesson. Based on this, he/she asks the students some questions; then, the teacher –
2. Mount specimens from the ditch on the microscope for students to observe.
Student’s Activities –
- Collect water from the ditch and view under the microscope to observe unicellular organisms.
- Observe prepared slides of their reproductive stages.
3. Request students to collect eggs of cockroaches and observe.
Observe the collected cockroach eggs and note your observations.
4. Collect maggots of housefly and keep for observations.
Observe the housefly maggots daily and note your observations
5. Collect eggs laid by a snail and keep in a closed container for observation.
Observe the snail eggs and take daily notes.
6. Collect some earthworms and keep in a suitable container for students to observe.
Student’s Activities – Observe and describe earthworms.
7. Summarizes the lesson on the board.
Student’s Activities – Copy as the teacher writes. Prepare a chart to show complete metamorphosis.
To conclude the lesson for the week, the teacher revises the entire lesson and links it to the following week’s lesson.
Ask 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?