Lesson Notes By Weeks and Term - Senior Secondary 2
Respiratory system 2
Respiratory system 2
TERM – 1ST TERM
WEEK SIX
Class: Senior Secondary School 2
Age: 16 years
Duration: 40 minutes of 5 periods each
Date:
Subject: Biology
Topic: RESPIRATORY SYSTEM 2
SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to
INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers, demonstration, videos from source
INSTRUCTIONAL MATERIALS: Videos, loud speaker, textbook, pictures
INSTRUCTIONAL PROCEDURES
PERIOD 1-2
|
PRESENTATION |
TEACHER’S ACTIVITY |
STUDENT’S ACTIVITY |
|
STEP 1 INTRODUCTION |
The teacher explain the mechanism of higher organisms to the students |
Students pay attention |
|
STEP 2 EXPLANATION |
Teacher explain the mechanism of lower organisms. |
Students pay attention and participate |
|
STEP 3 NOTE TAKING |
The teacher writes a summarized note on the board
|
The students copy the note in their books |
NOTE
RESPIRATORY SYSTEM
Mechanism of respiration in higher animals (inhalation and exhalation)
In higher animals, respiration involves inhalation and exhalation. During inhalation, the diaphragm contracts and moves downward, while the ribcage expands, creating a larger thoracic cavity. This decrease in pressure allows air to flow into the lungs, where oxygen is diffused into the bloodstream.
Conversely, during exhalation, the diaphragm relaxes, moving upward, and the ribcage contracts, reducing the thoracic cavity. This increased pressure forces air out of the lungs, expelling carbon dioxide, a waste product of cellular respiration. Together, these processes facilitate the exchange of gases, supplying oxygen to tissues and removing carbon dioxide from the body.
Mechanism of respiration in lower organisms
In lower organisms, such as single-celled organisms or simple multicellular organisms without specialized respiratory systems, respiration occurs through simple diffusion. These organisms exchange gases directly with their environment.
In unicellular organisms, like bacteria or amoebas, gases (oxygen and carbon dioxide) move across their cell membranes by diffusion. In some simple multicellular organisms, cells are in direct contact with the external environment, allowing for gas exchange through diffusion as well.
The absence of specialized respiratory structures in lower organisms reflects the efficiency of diffusion over short distances, meeting their basic respiratory needs. This contrasts with higher animals, which have developed complex respiratory systems to support larger and more metabolically active bodies.
EVALUATION: 1. Describe inhalation as a mechanism of respiration in higher organisms
CLASSWORK: As in evaluation
CONCLUSION: The teacher commends the students positively