Week1 Reactions of Life
Reactions of Life Pop Quiz
This week each pair of students will work with one spring onion, botanical name: Allium cepa . You will work from the visible anatomical scale, to the microscopic tissue scale and into the chemical molecular scale. You will learn the anatomy of the plant, its specialised cells and tissues and then test for the chemicals that are necessary for life.
The room will be arranged in five island groups so three pairs of students will work collaboratively, sharing the manual tasks.
Each student is responsible for following instructions, contributing to the tasks and recording their own observations and explanations in their Interactive Science Notebook.
The room will be arranged in five island groups so three pairs of students will work collaboratively, sharing the manual tasks.
Each student is responsible for following instructions, contributing to the tasks and recording their own observations and explanations in their Interactive Science Notebook.
Task 1 Observation and description of the organs of the Allium cepa
Left Page
Botanical Drawing of a longitudinal section of a Spring Onion with main organs labelled.
(This is an example of a botanical drawing. These three spring onions each have a flower.)
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Right Page
Longitudinal section of the Allium cepa
Carefully and neatly cut a longitudinal section to reveal the anatomy of the plant. Draw, identify and label the following organs;
Explain the function of each of these organs in relation to the life process of photosynthesis. Explain the function of each of these organs in relation to the life process of respiration. |
Task 2 Preparation of wet mounts and viewing with compound light microscope
Review the structure and function of the compound light microscope.
(Scroll to bottom of page to view a short video on how to turn your smartphone into a microscope.)
(Scroll to bottom of page to view a short video on how to turn your smartphone into a microscope.)
Task 3 Collaborative microscopy
This is where the collaboration between the three pairs of students begins. Each pair of students will make one wet mount of different tissue;
Share your slides within your island group. Each student is to complete a biological drawing of the tissues and label the cells observed. The following images will help you. |
Root Tip tissues
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Leaf base epidermal tissue
Green leaf epidermal tissues
Task 4 Chemical tests to identify some of the products synthesised by plants.
Left Page
Record your results here in a suitable scientific fashion |
Right Page
Carbohydrates (sugars and starch) and proteins can be detected by the use of an indicator, which is a chemical that produces a characteristic colour when a particular substance is present.
In this lab, you will test parts of the spring onion for various macro-nutrients, and compare your tests to standards, which are the results of tests that show a positive response for a known substance. SAFETY: Always wear safety goggles when working with chemicals.
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