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Natural sciences

Grade 9

Plants

Module 25

The microscope

Plants, like all other living organisms, consist of basic elements, or cells.

The structure of cells can be examined through a microscope. To be able to do this, it is necessary to learn how a microscope is operated. This will also unlock further possibilities in your studies.

Activity:

To explain the operation of a microscope

[lo 1.2, 1.3]

Your educator will introduce you to the parts of a microscope to show you how it is constructed and how it is used, and to give you the rules for when you use such an expensive piece of apparatus.

Activity:

To identify the different parts of a microscope

[lo 2.1, 2.2, 2.4]

Assignment 1:

  1. Complete the labels for the sketch.
  2. Write down the functions of the parts:
Part of Microscope
1. Eyepiece / ocular
2. Barrel
3. Arm
4. Coarse adjustment screw
5. Fine adjustment screw
6. Rotating nose-piece / objective turret
7. Objectives / lenses
8. Clamps
9. Stage
10. Diaphragm
11. Condenser
12. Light bulb or mirror

3. Write down some of the important rules for handling a microscope:

4. Explain how to determine magnification:

5. What is the magnification to which the microscope that you are using has been set? Show your calculation.

Assessment: The functions of the microscope

Were you able to identify the names and functions of the basic parts?

[LO 1.2; LO 1.3]

Activity:

To use the microscope as apparatus

[lo 1.2, 1.3]

Assignment 1 Work together in groups to do the following:

  1. Use a transparency pen to write on an object slide and examine the writing, using a low magnification.
  2. Tear a small strip of paper, place it on the object slide and examine it through the microscope.
  3. Select something of your own choice: a small dead insect, perhaps an ant, or one of your own hairs, for examination.
  4. Examine a few grains of sugar.

Write notes on what you observe.

Assignment 2:

Prepare a wet specimen from a piece of the epidermis of an onion leaf. Your educator will demonstrate the technique for doing this. First use a low magnification for studying the specimen and then increase the magnification.

Draw the specimen as seen with the naked eye, and then as seen through the microscope.

The brick-like structures are cells . The whole body of any plant or animal (including people) is built up of cells .

Assignment 3:

You are now experienced in handling a microscope. Write down any suggestions that you would like to mention about handling the microscope and adjusting it for finding the correct image.

Why might you want to use a colorant to stain the specimen?

Ask your educator about a suitable colourant.

Assessment: The practical use of the microscope

Were you able to handle the items and complete the sketches?

[LO 1.2; LO 1.3]

Assessment

LO 1: Scientific investigations:

The learner will be able to act confidently on curiosity about natural phenomena, and to investigate relationships and solve problems in scientific, technological and environmental contexts.

This is evident when the learner:

  • conducts investigations and collects data;
  • evaluates data and communicates findings.

LO 2: Constructing Science Knowledge:

The learner will know and be able to interpret and apply scientific, technological and environmental knowledge.

This is evident when the learner:

  • recalls meaningful information;
  • categorises information;
  • interprets information;

2.4 applies knowledge.

Memorandum

MINIMUM CONTENT

Activity 1

Assignment 1:

  • Plants, like all other living organisms, consist of basic elements or cells.
  • The structure of cells can be examined through a microscope. To be able to do this, it is necessary to learn how a microscope is operated. This will also unlock further possibilities in your studies.

HOW A MICROSCOPE IS CONSTRUCTED

FUNCTION
Lens at the upper end of the barrel facilitates enlargement
Beams of light travel through this barrel, which separates the ocular and the objectives
Handle for holding
Moves the stage towards the object lens; Initial focussing
For finer, closer focussing
For moving objectives into position
These lenses make it possible to achieve different magnifications
Holds the microscope slide in position
For the positioning of the microscope slide
Controls the amount of light that passes from the object to the eye
Concentrates light on the object
Light source

How to handle a microscope

1. Carry it carefully – using both hands.

2. Take care not to mark it with fingerprints.

3. Never remove the lenses.

4. Handle the highest objective with great care.

5. Protect the microscope from dust and damp.

Magnification

  • Value on the objective x value on the ocular
  • E.g.: 10 x 40 = 400 x magnified

Activity 2:

Assignment 1:

  • Practical

Assignment 2:

Wet specimen

1. Select a microscope slide / object glass and wipe it clean.

2. Use a dropper to place a single drop of water in the centre of the slide.

Water dropMicroscope slide

3. Using a tweezer or dissecting needle, select the object (specimen) and place it in the drop of water. Open it up and flatten it.

4. Stand a dissecting needle vertically in the centre of the object.

5. Position a cover-glass at an angle against the needle.

6. Quickly remove the needle to allow the cover-glass to fall into place over the specimen.

7. Tap the cover-glass lightly, using the back of the needle, to release bubbles that might be trapped.

8. Use an iodine solution to stain the specimen for greater cell definition. Starch ­grains will also be stained.

Questions & Answers

what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
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Cied
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Natural sciences grade 9. OpenStax CNX. Sep 15, 2009 Download for free at http://cnx.org/content/col11069/1.1
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