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Transcript
Draft Standard Biology 2.8: Investigate biological material at
the microscopic level
Resource Title: The Micro World
Credits: 3
Teacher guidelines
The following guidelines are supplied to enable teachers to carry out valid and consistent
assessment using this internal assessment resource.
Read also the Explanatory Notes for Achievement Standard Biology 2.8. These notes
contain information, definitions, and requirements that are crucial when interpreting the
standard and assessing against it.
Context/Setting
This activity requires students to investigate biological material at the microscopic level. The
context is the “micro world” of plants and unicellular organisms. Through practical
microscope work students will investigate biological material by preparing specimens to view
under light microscopes and recording their observations as biological diagrams. Following
their practical work students will write a report that gives reasons for how or why observed
specialised features enable the cells to effectively carry out their specific function(s).
Conditions
The biological diagrams should come from several practical sessions completed by the
students.
These sessions must include two different plant tissues and one unicellular organism;
suitable specimens include silverbeet leaves, rhubarb leaves, daffodil or onion shoots,
filamentous green algae, Elodea, Paramecium.
These sessions may include preparation techniques such as staining, use of cavity slides,
use of cellulose, epidermal tear, cutting transverse sections.
Students should work individually to prepare specimens, view under a light microscope and
record observations as biological drawings.
Students should hand in their biological drawing(s) at the end of each session.
The written report is to be completed individually in exam conditions; students will need
access to their biological drawings. It is suggested that this will take 1 class period.
Resource Requirements
Students will need access to light microscopes, glass slides (flat and cavity), cover slips,
suitable stains such as iodine, droppers, tweezers, toothpicks, blotting paper.
They will need to be provided with suitable plant material and unicellular organisms for
viewing under a light microscope. Paramecium can be purchased through outlets such as
“Biosuppliers” and is easily cultured by keeping in a jar of water to which a handful of straw
has been added, keep in a dark, even temperature environment. Suitable plant material is
easily purchased at supermarkets or found in school / staff gardens.
It may be possible to complete the practical sessions at a local university or polytechnic as
part of a fieldtrip.
A clearfile for each student would be helpful for teacher collection of completed biological
drawings.
Draft Standard Biology 2.8 (AS91160): Investigate biological material
at the microscopic level
Resource Title: The Micro World
Credits: 3
Achievement
Achievement with Merit
Investigate biological material
at the microscopic level
Investigate in-depth biological
material at the microscopic
level
Student Instructions Sheet
Introduction
This assessment activity requires you to prepare and view biological material under a light
microscope and record your observations as biological drawings. You will then write a report
giving reasons for how or why observed specialised features enable the cells to effectively
carry out their specific function(s).
When writing your report you will have access to your completed biological drawings.
Insert conditions for assessment here e.g.
Practical sessions will take place on <dates> and will be <time> in duration each
The report writing session will take place on <date> and will take 1 class period
All work is to be completed individually
Part A - Practicals
There is no need to include all practicals below. Teachers should select two different
plant tissues and one unicellular organism and delete the rest
Silverbeet leaf tear
Rhubarb leaf tear
Onion bulb epidermis
Onion shoot transverse section
Daffodil shoot/leaf transverse section
Filamentous green algae
Elodea
Paramecium
For each practical you will need to –




Prepare the biological material for viewing under a light microscope
View specimen using a light microscope correctly so details of cell structures can be
seen
Record your observations as a biological drawing on the paper provided
Ensure the marker has checked your slide before removing it from the stage of
microscope
Part B – Written Report
For each of your biological drawings in Part A 
Describe the function of the cell/tissue

Relate the labelled features/organelles to the function

Explain how or why these features enable the cells to effectively carry out their
specific functions.
Draft Standard Biology 2.8 (AS91160): Investigate biological material at the
microscopic level
Part A: Insert tissue/organism name here (there needs to be 3 of these)
Student Name ________________________________ Date ____________
Space for biological diagram:
Draft Standard Biology 2.8 (AS91160): Investigate biological material at the
microscopic level
Part B – Written Report
Insert tissue/organism name here (there needs to be 3 of these sheets)
Describe the function of the cell/tissue
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
From your biological drawing choose TWO features/organelles Feature 1 _________________________________________________________________
Explain how or why this feature/organelle enables the cell(s) to effectively carry out their
specific function.
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
Feature 2 _________________________________________________________________
Explain how or why this feature/organelle enables the cell(s) to effectively carry out their
specific function.
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
Assessment Schedule: Biology 2.8: Investigate biological material at the microscopic level
Evidence/Judgments for Achievement
Credits: 3
Evidence/Judgments for Achievement with Merit
Investigate biological material at the microscopic level
Investigate in-depth biological material at the microscopic level
Evidence should come from biological drawings and report
Evidence should come from biological drawings and report

Prepared slide allows identifiable features to be determined
i.e. thin, flat specimen/correct stain/few air bubbles/no excess liquid/cover slip
present
 Plant Tissue 1
 Plant Tissue 2
 Unicellular Organism

Viewing under light microscope allows identifiable features to be determined
i.e. suitable magnification used/focused
 Plant Tissue 1
 Plant Tissue 2
 Unicellular Organism

Use a biological drawing to record observations
i.e. use of conventions such as use of pencil, appropriate size of drawing, solid
lines drawn, correct title and magnification, correct feature/organelle labels (at
least 3)
e.g. pencil used, title, magnification and labels correct but cell nucleus and cell shape does not
reflect what seen at 400X mag
 Plant Tissue 1
 Plant Tissue 2
 Unicellular Organism

Prepared slide allows identifiable features to be determined
i.e. thin, flat specimen/correct stain/few air bubbles/no excess liquid/cover slip
present
(as for Achieve)

Viewing under light microscope allows identifiable features to be determined
i.e. suitable magnification used/focused
(as for Achieve)

Use a biological drawing to record observations that are consistent with
material being viewed
i.e. recognizable shape/proportions, inclusion of typical organelles consistent
with magnification
e.g. accurately reflects what seen at 400X mag for Elodea
 Plant Tissue 1
 Plant Tissue 2
 Unicellular Organism

State function(s) of TWO features/organelles and correctly relate to function of
tissue/organism
e.g. Stomata are where gases enter and exit leaves as part of photosynthesis in the leaf. Guard
cells open and close stomata (control stomata size) during photosynthesis.
 Plant Tissue 1
 Plant Tissue 2
 Unicellular Organism

Explain how or why TWO features/organelles enable the tissue/organism to
effectively carry out their specific function(s)
e.g. Onion epidermal cells have a cell wall which is used for support. This is needed as the cells
are storing water and nutrients and there is turgor pressure. Without cell walls the epidermal
cells would burst (lyse). Onion epidermal cells do not have chloroplasts, which is because the
tissue involved is to do with storage of energy as an underground bulb. This means it is not
exposed to light and therefore chloroplasts would have no use as chloroplasts convert light
energy using photosynthesis.
 Plant Tissue 1
 Plant Tissue 2
 Unicellular Organism
TWO of the three needed
All criteria must be met for Achievement
All criteria must be met for Merit
Name:
Class:
Signature:
Date:
Grade: