Database of Biological Experimets in English

THE DATABASE ON
LABORATORY INVESTIGATIONS IN BIOLOGY
Please provide me with the URLs of the websites on
biology education connected to following subjects.
Please send your E-mail to MITSUO SAITOH
rxp04450@nifty.com

Introduction
1. How to use the Microscope l 2. Micrometer

The Structures of Organisms
3. The Observation of the Cell l 4. Cytoplasmic Streaming l 5. Osmosis and Plasmolysis
6. The Structure of Plants l 7. The Structure of Animals
8. The Observation of Somatic Cell Division (Mitosis)

Metabolism and Energy
9. Enzyme, "Catalase" l 10.Alcoholic Fermentation l 11.Enzyme, "Dehydrogenase"
12.Separation and Examination of Chloroplast Pigments l 13.Simple Manometer
14.The Luminescence of Vargula hilgendorfii

Reproduction and Development
15.Pollen Tube Growth l 16.The Observation of Fern's Prothallium
17.The Observation of Reductive Division (Meiosis)
18. The Fertilization and Development of Sea-Urchin l 19.Plant Tissue Culture

Heredity
20.The Human Genetics l 21. Polytene Chromosomes in the cells of Salivary Gland
22.The Heredity of Drosophila melanogaster l 23.The Extraction of DNA

Homeostasis
24.The Observation of Blood Cells l 25.Nervous syetem,"The Neuron"
26.The Dissection of Cow's Eye l 27.Avena test l 28.Weber's Law

Ecology and Environment
29.The Growth Curves l 30.Plant Community Ecology l 31.The Ecosystem

Diversity
32.The Observation of Plankton and others l 33. The Investigation of Water Bear

Articles
34.Comics on the Laboratory Investigations in Biology drawn by Students
35.New Ideas on Teaching Materials of Biological Sciences Education


Return to the top


How to Use Light Compound Microscope
Introduction
The microscope is an instrument designed to examine objects too small tobe seen with the naked eye. Unaided, the human eye cannot distinguish objectsmuch smaller than 0.1 mm. The microscope acts are as an extension of theeye, allowing it to see objects beyond this range. The compound moncularmicoroscope, illustrated in follwoing Figure, is the type of microscopemost commonly used. With this instrument, the image is seen with one eye.Usually the light passes through the object before reaching the eye.Whilethe lens of your eye antomatically adjusts to focus on anobject being viewd,the lenses of a microscope are focused mechanically. A pair of wheels --the coarse and fine adjustments -- move the lenses toward or away fromthe object being viewd. In some microscopes the stage and the objects aremoved instead of the lenses. An important factor in using the microscopeis the distance between the object viewed and the objective lens of themicroscope. For proper focusing, the lens must be much closer to the objectunder high magnification than under low. Remember that there is greaterrisk of crushing a slide when using high power than low. In using the microscopeit is important that to know how much you are magnifying an object. Tofind the maginification, multiply the number on the eyepiece by the numberon the objective being used. If the eyepiece power is 10x and the objectivepower 43x, for example, the total maginification is 10 multiplied by 43,or 430x.
How to Use the Microscope
A. Care of the microscope
Your microscope is an expensive instrument that must be given proper care.Always follow these general instructions when using a microscope.
1. Always carry the microscope wih both hands, one hand under the base,the other on the arm.
2. When setting the microscope on a table, always keep it away from theedge. If there is a lamp attached to the instrument, be careful of thewires. When working with a microscope, it is generally best to clear yourlab table of everything that is not absolutely needed.
3. Avoid titling the microscope when using temporary slides made with water.
4. The lenses of the microscope cost almost as much as all the other partstogether. Never clean
3>them with anything other than lens paper.
5. When getting ready to put the microscope away, always return it to thelow-power setting.

B. Setting up the microscope
1. Place the low-power objective in place if it is not already so fixed.(In changing from one objective to another you will hear a click when the objective is set in position.)
2. Move the mirror so that light is reflected upward through the openingin the stage. Most microscopes are equipped witha diaphragm for regulatingthe light. Get the right amount of light for the object being viewed. Somematerials are best viewed in dim light, others in bright light.
3. Make certain that the lenses are clean.

C. Practice in the Use of the microscope.
1. Cut out the letter "H" provided by your teacher. Place this on a cleanslide, and with a dropper place one drop of water on the letter.
2. Wait a moment before covering witha cover slip. Hold the cover slipat about a 45 degrees-angle to the slide, and then slowly lower it. A gentletapping will usually remove any bubbles that may be present.
3. Place the slide on the stage and clamp it down. Move the slide so thatthe letter is in the middle of the hole in th stage. Make certain thatthe low-power ojjective is in place. Viewing the stage from the slide,use the coarse adjustment wheel to lower the objective until either thestop is reached that will prevent further lowering or the the objectiveis appoximately 2 cm the cover slip.
4. Looking through the eyepiece, raise the objective until the letter isin focus. How has the letter changed from its appearance to the naked eye?Leave the slide where it is and switch to high power. The letter shouldbe in focus. Most microscope are "parfocal"; that is, switching objectiveswill not affect the focus.(When the high-power objective is being used,never use the coarse adjustment!)
5. Cut out one letter "F". Make a wet mount and examine it under low power.What appears to have happened to the letter?
6. Make a wet mount of a letter "F". What appears to have happened to theletter?
7. Make a wet mount of two differently colored hairs crossed over one another.Observe these under high power, adjusting the focus as you do so. It isimportant to remember that by using
the adjustments you bring the microscope into focus at many different levels.At each setting
you can see clearly only one plane of the object. To see other planes clearlyyou must change
the focus. It is impossible to see all parts of a thick object clearly at one focus.

References
BIOLOGICAL SCIENCE," Molecules to Man" BSCS (Houghton Mifflin)

LINKS
Nikon Corporation
Olympus Optical Co.,Ltd.
Carl Zeiss

Return to the Database



The Observation of Somatic Cell Division
(Mitosis)
CELL DUPLICATION IN PLANT CELLS
Background
Just back of the tip of each young root of a newly sprouted plant the cells are actively diving. The rootlets can be snipped off and placed in a chemicalfixative (to kill and preserve the cells), softened (to separate the cells),then stained, and the finally pressed between slide and cover glass tomake a "smear" preparation in which the stages of cell division can be observed.Or, fixed root tips can be imbedded in paraffin sectioned into very thinslices, and then stained and mounted on slides in a permanent form.
Eithr make your own slides according to your teacher's directions, or examine prepared slides of dividing cells in a root tip.
Procedure
Place the slide on the microscope stage and examine it under low power.Scan the entire section; observe that cells far from the tip and cellsright at the tip are not actively dividing. Locate the region of activecell between these two regions. Change to the high power objective. Asyou observe the cells, focus up and down slowly with the fine adjustmentto bring different structures into sharp focus. Find cells at various stagesof division. Remember that when the slide was prepared each cell was killedat a different stage during a continuous process. What you are observeingis comparable to seeing scrambled, isolated frames of a motion picture.Try to imagine how you would piece the picture togehter. Make sketchesof the different stages and try to determine what their proper order is.In particular, you should be able to distinguish the following stages:
1. Find a cell in which the nucleus is readily visible as a large, roundbody. In this stage you should also be able to locate round, stained bodieswithin the nucleus. These are the nuceoli.
2. In a somewhat later stage, the membrane around the nucleus begins todissolve so that nucleus and cytoplasm are no longer separated. The nucleolusor nucleoli have begun to dissappear. If you focus carefully, you may seethe chromosomes, the threadlike or rodlike structures which determine theheredity of the cell.
3. A strucutre called the spindle appears in the area formerly occupiedby the nuclear membrane. The spindle, which tapers toward each end of thecell and appears to be composed of fibers, is actually a firm structure.The ends of the spindle are called poles. In theis stage, the chromosomeshave become thicker and shorter and each of the chromosomes has becomeattached to the middle of the spindle. You will probably be able to seethat the chromosomes are actually double.
4. In a later stage stage, each chromosome separates lengthwise into twohalves. Each half, which scientists do not agree, each of new chromosome,is attached to the spindle. By forces about which scientists do not agree,each of the new chromosomes has begun this movement.
5. The separated chromosomes have become less thick and more lightly stained.Each group has begun acquire a new nuclear membrane around itself. A new cell wall forms across the equator of the spindle, resulting in the formationof two new cells from the single parent cell.
CELL DUPLICATION IN ANIMAL CELLS
The developing eggs of sea animals such as starfish, sea urchins, and fishesare excellent subjects on which to observe the stages of cell divisionin animal cells. The developing eggs of the parasitic worm Ascaris arealso often used. The eggs can be killed and stained by procedures verysimilar to those used for the plant tissues you have examined.
Procedure
Examine a slide of developing Ascaris or whitefish embryos. Find a cellin which the chromosomes are long and threadlike. Try to count the numberof individual chromosomes. (In Ascaris eggs this is easy, but in the whitefishembryos it is almost impossible.) Find a cell in which the chromosomesare located at the equator of the spindle. Compare the poles of this spindlewith those of the spindles in the dividing plant cells yo have studied.Find a cell in which the chromosomes are separating and the cell has begunto constrict. Compare this method of separation of the "daughter" cells withthe method you observed in plant cells. What structures do you see in thedividing animal cells that were also present in the dividing the palntcell? What strucutures do you see that were not present in the dividingplant cell?
Result
The following picutres show the stage mitosis in the root tips of Onion(Allium cepa L.).
And they have been taken by a Digital Camera through light compound microscope.
　　　

Discussion
1. How are plant mitosis and animal mitosis similar?
2. How are they different?
3 Compare the number of chromosomes in the two daughter cells with the number in the parent cell.
4. Can you tell from the slide the order of the various stages of mitosis?
References
BIOLOGICAL SCIENCES Molecules to Man BSCS (Blue Version) Houghton Mifflin
LINKS
Movie of Mitosis (Plant Cell Division)


Return to the Database


The Observation of Plankton and others

Phytoplankton and others in Fresh Water

CYANOBACTERIA IN KINGDOM MONERA
Cyanophyceae (Blue-green algae)

A : Microcystis B : Nostoc C : The whole of Nostoc D : Anabena E : Cylidrospermum
F : Oscillatoria G : Oscillatoria(x110) H : Calothrix I : The magnifyingfigure of the adhered part of Calothrix J : Rivularia

CONJUGATAE IN KINGDOM PROTOCTISTA
Zygnematales

A : Cosmarium B : Cell wall of Cosmarium C : Cosmaruium in the stage ofdivision D : Euastrum E : Microsterias F : Closterium G : Netrium H : Pleurotaenium
I : Spyrotaenia J : Desmidium K : Arthrodesmus L : Zygnema M : Spirogyra(2 zygotes) N 〜 R : Germination of Spirogyra's zygote S : Mugeotia T :Sirogonium

CHLOROPHYCEAE IN KINGDOM PROOCTISTA

A : Chlamydomonas(x1500) B : Chlamydomonas(x420) C : Haematococcus D :Tetrapora(Whole of colony) E : Tetrapoda F : Cells in colony G : KirchneriellaH : Protococcus
I : Scenedesmus J : Scenedesmus(x800) K : Pediastrum L : Hydrodictyon reticulatumLargerheim M : Hydrodictyon reticulatum Largerheim N : Ulothrix zonataO : Ulothrix zonata (x430) P : Zoospore of Ulothrix zonata Q : Whole ofChaetophora R : Chaetophora
S : Draparnardia plumosa Kuntzing T : Oedogonium U : Bulbochaete V : Vaucheria(x100)W: Vaucheria(x100) Z : Zoospore of Oedogonium

Return to the Database


The Investigation of Water Bear

Tardigrada

Water bear in the book, "Five Kingdoms"

Because of their pawing locomotion, the nineteenth-century English naturalistThomas Huxley called tardigrades water bears, a name by which they arestill called today. Tardegrades move dliberately on four pairs of unjoinedstumpy legs, each having four movable claws, pegs, or adhensive disks.They all lack cilia. The head and four body segments of tardigrades aregenerally covered with a thick, conspicuous, nonchitinous, protein cuticle,which is periodically molted. Although tardigrades are coelomate metazoans,the coelem is limited - it lies around gonad only. The main body cavityis a pseudocoel. From the mouth protorude sharp feeding organs called styles;new ones are secreted at each molt. Tardigrades range in length from 50μm to 1.2 mm. They lack respiratory and circulatory organs; gases andfood simply diffuse in their body fluids. Oxygen and carbon dioxide areexchanged directly through the body surface. Tardigrades lack circularbody-wall muscles, but have thin, smooth longitudinal liquid food. Somepierce plant cells with their styles., ingesting the liquid witha sucking,muscular pharynx. Others prefer to eat the body fluids of rotifers, nematodes,and even other species of tardigrades. A large stomach opens into a shortrectum. Excretory granules are left in molted cuticles. The pharynx, andfive ventral ganglia are connected by pairs of longitudinal nerves. Mosttardigrades have a pair of red or black eyespots. Tardigrades are mostremarkable for their powers of residence. They can survive desiccationand temperatures as high as 151℃ and as low as -270℃, nearly absolutelyzero. Species from the arctic, from the tropics, and even from the hotsprings are known. Surface water of moss and lichens, algae, soil, andinterstitial spaces of lake and marine sands are tardigrades habitats.Tardigrades can turn into dry barrel-shaped, motionless, forms, calledtuns because they resemble wine casks. In this state they can survive foras long as 100 years. They also form thick-walled cysts, different formtuns, in response to hunger and damage. Inside the cyst, the animal contractsand the interstitial organs degenerate. Cysts (but not tuns) may form inaquatic environments. Scientists would like to discover the principle orproperty which gives tardigrades their great resistance to X-radiationfor possible application in future space travel. For human beings, thelethal dose of X rays is about 500 roentgens; for tardigarade, it is 570,000.
A single ovary or testis lies dorsal to the gut. Although the sexes areseparate, the males and females are often difficult to distinguish. Mostare female. A few species in the genera Pseudoechiniscus and Echiniscusreproduce perthenogenetically: females lay eggs that grow into femaleswithout any male intervention. In species that reproduce sexually, fertilizationmay be internal or external. In some freshwater tardigrades, the male injectssperm through the female's genital pore or anus into the space betweenthe new and old cuticle; the fertilized eggs are shed with the old cuticle.Tardigarade eggs have thin or thick shells. Thick-shelled eggs are reproducedwhen conditions or growth are unfavorable. Fertile eggs are often sticky;they can b found attached to moss, algae, bark, and other objects. Theeggs develop directly into adults; water bears have no larval stages. Underfavorable conditions, after about two weeks of development the young waterbears hatch from their egg cases., which they rupture with teir styles.After hatching, tardigarades grow by enlargement of existing cells, ratherthan by mitotic division to increase the number of cells.
Tardigrades have left few fossils. They are considered to be related tothe arthropods particularly the mites, because of their styles, four pairsof legs, and segmented bodies. Like arthropods, they probably evolved fromannelids. Tardigrades may be descended from a middle Cambrian Aysheaia-likeanimal.
References
FIVE KINGDOMS - An illustrated guide to the phyla of life on earth - (Secondedition)
by Lynn Margulis and Karlene V. Schwarz (FREEMAN) 1988
Return to the Database


Comics on the Laboratory Investigations in Biology drawn by Students
The Observation of Paramecium through Microscope
A student's work

How to Examine Plant's Name through Computer
(1)What name does this plant have?　　(2)Let's examine it through computer!
(3)I could know it.　(4)Oh my god! No leaves!
A teacher's work

Animation of Amoeboid Movement and Mitosis by a teacher
　　　　　　

[LINKS]Biology Cartoons by T. McCracken l Benita Epstein Cartoons

Return to the Database

Return to the top















UNDER CONSTRUCTION !!



SORRY!



Return to the Database