Chapter 2 : Cells as a basic unit of life. Flashcards
A slide consists of….
a piece of glass, a stained specimen and a thin cover slip
We use a slide to
to hold the specimen for examination under the microscope.
Give examples of dye solution.
Iodine solution, methylene blue.
What is dye solution used for?
It is used to highlight the structures in the specimen.
A complete slide slide has three components and they are
A glass slide, a piece of glass, stained specimen
What is the first step of preparing a slide of a human cheek cell?
Scrape the inside of the cheek with the blunt side of the toothpick.
The second step of preparing a slide of a human cheek cell.
Place the cells on a glass slide and add a drop of distilled water.
The third step of preparing a slide of a human cheek cell.
Add a drop of methylene blue solution.
The fourth step of preparing a slide of a human cheek cell.
Gently place a cover slip using a mounting needle.
The fifth step of preparing a slide of a human cheek cell.
Remove excess water and methylene blue solution using filter paper.
The first step of preparing a slide of plant cells.
Remove a piece of onion from the bulb.
The second step of preparing a slide of plant cells.
Peel off the inner epidermal layer.
The third step of preparing a slide of plant cells.
- Place a drop of distilled water on a glass slide.
- Place the inner epidermal layer as flat as possible on the slide.
The fourth step of preparing a slide of plant cells.
Gently place a cover slip on the specimen.
The fifth step of preparing a slide of plant cells.
- Add a drop of iodine solution at one end of the cover slip.
- Place a piece of filter paper at the oppisite end to draw the stain across the specimen.
What is irrigation?
Irrigation is an alternate techinique of staining specimens. The stain is drawn from one side of the cover slip to the other with a filter paper.
The functions of a microscope :
- a microscope helps us observe and study the structures of cells.
- a microscope magnfies the size of minute objects that cannot be seen with the naked eye.
- the light microscopes are commonly used in school.
Name the parts of the microscope.
eyepiece, body tube, course focus knob, fine focus knob, revolving nosepiece, objective lenses, arm, stage, clip, diaphragm, mirror, base.
Name the function of the parts in the microscope.
eyepiece : To see the specimen.
body tube : light enters the eyes of the observer through this tube.
course focus knob : To bring the image into view.
fine focus knob : To sharpen the image.
objective lenses : To enlarge the image of the specimen based on different magnifications.
arm : This is where you hold when carrying the microscope.
stage : this is where you put the slide with the specimen.
clip : To hold the slide in a fixed position.
diaphragm : To control the amount of light that passes through the specimen.
mirror : to reflect light from the light source into the specimen.
base : to support the microscope.
What are the two types of microscope?
stereo microscope, compound microscope.
What is the function of a stereo microscope?
The stereo microscope is used to view larger objects such as insects.
- enlarge up to 200 times.
- shows three-dimensional view of small objects.
What is the function of a compound microscope?
- to view thin slices of specimens, such as onion cells.
- specimen must be thin enough to allow light to pass through it.
- enlarge up to 1500 times.
- shows two-dimensional view.
What did Robert Hooke first oberved and with what microscope?
Robert Hooke first observed a thin slice of cork using a compound microscope.
What is the difference between the old compound microscope and the modern-day microscope?
A modern-day microscope has a built-in lamp instead of a mirror.
