BIOLOGY PRACTICAL 114
FOR NCE I
FIRST SEMESTER
R EQUIREMENT FOR PRACTICAL CLASS IN BI OLOGY LABORATORY
Working in the Biological laboratory is quite dangerous and required a special case, if you are not serious about safety precousion. The main types of laboratory hazard are, chemical, Biological, Electrical and fire hazard. So precousion must therefore be observed by all members of the laboratory.
CHEMICAL HAZARD:- In chemical hazard care most be taking for proper storage, labeling of chemical and arrangement of class where that contain chemical thus reduce accident course by chemicals and other flame chemical. The following symbols should be observed to avoid chemical hazard in the laboratory.
Toxic Corrosive Oxidizing Flammable Harmful Explosive
2) BIOLOGICAL HAZARD:- The main sover of Biological hazard is from living organism, so Therefore care must be taking when handling such specimen. E.g. Biological Animals culture media, Bacterial and fungal etc.
3) ELECTRICAL HAZARD: - When working in laboratory you are also working with electrical materials such as water bath laboratory incubator, hot, plate, microscope and other electronic materials so care must be taking to avoid Damaging and coursed hazard.
4) FIRE HAZARD: - Since you are working with flammable and explosive chemicals in the laboratory so care must be taking to avoid coursing of fire hazard.
SAFETY MEASURE IN THE LABORATORY
The following are some of the measured to be taking well working in the laboratory.
Do not touch anything in the laboratory until you are told to do so
No eating, Drinking and playing in the laboratory.
Children are not allowed in to the laboratory.
Always remove any jeweler when working in the laboratory
Ensured you switch all electrical appliances and after each laboratory.
Disposed all wastes materials in Dustbin.
Do not sit on work surface of the tables
Return all equipment or materials to their original position after conducting practical.
Never run around in the laboratory and maintain silent.
Always wear lab-coat and hand glove during practical to avoid infection
EXAMINATION OF BIOLOGICAL SPECIMEN USING HANDLENS
In Biology laboratory Biological specimens can be examined by the use of an instrument or magnifying glass called handles. Hand lens is a convex lens that is used to produce a magnified image of an object. The lens is usually minted in a frame with a handle, and magnification is usually x10 mg of the original size of the specimens.
RULES OF MAKING BIOLOGICAL DRAWING
In Biology laboratory Drawing can be made using several method. Must biologist, Technologist or scientist follow the some tulles for making drawing in order to be neat and easy to read?
The following rules are consider for Biological Drawing
Always use HB pencil
The lines of the Diagram should be very thin but clearly visible.
The labels should be at side of the drawing and also write in pencil.
The lines must never cross each other.
Avoided shading of line
Always label the diagrams fully and writing the title of the diagram at the bottom.
Always the diagram should be free hand sketched
Use online paper for the Diagram.
MICROSCOPE
This are the basic tool of the biologist in laboratory that enable biologist to investigate living thing and object that are too small to be seen with un necked eye. The Microscope is able to magnify tine specimen by means of lenses located in the eyepiece and objectives lens. Microscope are the instrument which use to magnified image of an object.
TYPES OF MICROSCOPE
The microscope is divided in to two that is light microscope and electron microscope. The compound light microscope is also be divided in to two monocular and binocular microscope.
The principal on which magnification is based on microscopic light microscope. Include: Bright fields, Dark fields, phase contrast and flu recent microscope. The bright field is most widely employed for routing microscope while other are used for special purpose.
PART OF MICROSCOPE AND THEIR USES/ FUNCTION
EYEPIECE: - This are the lens to at the top of the microscope that you look though. The eyepiece is usually x10 or x 15 power.
REVOLVING NOSE PIECE OR TUBE :- this is the part of microscope that holds two or more objective lenses and can be rotated to easily change power (magnification)
OBJECTIVELENSES: - in compound microscope usually have three (3) or four (4) objective lenses almost consist of X4, X10, X40, and X100 power.
STAGE:- the stage is the flat form where your place your slide if your microscope have a mechanical stage you will be able to move it left and right or forward and backward.
ARM:- Arm support the tube and consist it to the base of microscope.
CLIP HOLDER:- this is a part of microscope which located on the stage that are use to hold the slid.
CONDENSER:- the purpose of condenser is to focus the light on to the specimen by sharpening the image then those with no lenses.
ILLUMINATOR:- A steady light source (110v) used in place mirror. It is used to reflect light from an external light source up through the buttons of the base.
COARSE AND FINE ADJUSTMENT: - Bring the specimen into general focus and detail.
BASE:- the button of the microscope, or used for support
CARE AND MAINTENCE OF MICROSCOPE
Always after using microscope cover it with dustcover
Clean the lens regularly with lens tissue and x y lane
Do not touch the glass part of microscope with finger of lens mirror
Always carry microscope by the arm and one hands supporting the base.
After using immersion oil clean off residue immersion oil immediately
Avoid tracking dirty and oil residue to other areas of the microscope
DATA COLLECTION ANALYSIS AND PRESNTATION
When scientist conduct various experiment and do research, the collect vast amount of information for example.
Measurement, description and other observation.
Data is define as the collection of facts, such as values or measure things, it can be number, word, measurement observation or even just description of things.
You will be responsible for completing data tables for many laboratory investigation each column in a data table has a heading. The column Heading explain ware particular data to be placed
The completed data table will help you to interpret the information you collected and answer the question found at the end of each laboratory investigation. E.g.
HAIR COLOUR
Brown
Black
N.C.E. I
5
8
N.C.E. II
6
5
N.C.E. III
4
6
TOTAL
15
19
FORMAT FOR REPORTING BIOLOGY PRACTICAL
The purpose of written Biology lab reports is to determine how well you performed the experiment, how much you understand what happen during the experimentation process and how you can convey that information in an organized fashion. A good laboratory observation or report has the following format which include;
Practical Number,
Date,
Title
Aim,
Materials,
Theory,
Procedure,
Observation,
Diagram,
Precaution.
Conclusion
SECTIONING AND STAINING TECHNIQUE
Animal tissue must to be cut or slide into thin section. Cut is predetermined thickness to be seen microscopically if the section is too thick that is having too many cells ligh cannot pass through and details cannot be studied. Sectioning can be obtained with the use of instrument called microtone. Microtone is an instrument used for cutting thin slides of materials to be used for microscopic slides. In Biology sectioning undergoes through the following process known as Tissue-preparation.
Fixation_______ _Stabilizes and preserves the tissue
Embedded ___ Converts the tissue into a solid form which can be sliced (sectioned)
Sectioning (Slicing)_______provide the very thin specimens needed for microscopy.
Staining ______________________provides visual contrast and may help identify specific tissue components.
TYPES OF MICROTONE
Rotary microtone
Base sledge microtone
Sliding microtone
Freezing microtone
Staining: - this is an auxiliary technique used to enhance and contrast the microscopic image. Staining and dye are frequently used in biology and medicine to highlight structure of biological tissue for viewing often with aid of different microscope.
Staining is a substance that adheres to a cell, giving the cell colour. The presence of colour gives the cell significant contrast so they are much more visible.
KIND OF STAINS
Staining are classified as followed.
Simple staining: - this involve immersing the sample in dye solution, followed by rising and observation. E.g. crystal violet, methylene blue and carbon fuchsine.
Differential staining: - in this procedure involve more than one dye, this help to divide the bacteria in to separate groups based on staining characteristic. Gram stain and Acid fast stain. E.g. in the staining of mycobacterium tuberculosis.
Special or structural staining: - this may involve the stain of a special structure in an organism; e.g. stains for metachromatic granules, stain for flagella, stain for capsules.
PREPARATION OF MICROSCOPIC SLIDE
In Biology laboratory when preparing microscopic slides for observation, it is important to have all the necessary materials either are permanent or temporary slides
PERMANENT SLIDE: - This are slid that lasting for a long period of time without washing in the future existing all the time needed.
TEMPORARY SLIDE: - are slide which prepared for a period of time not lasting and earn easily washing.
PREPARATION TECHNICS
DRY MOUNTS: - this is simply position a thin sliced section on the center of the slide and place a cover slip over the sample. This is an ideal for observing hair, feather, pollen, dust, as well as dead organisms such as insect.
WET MOUNT: - used for aquatic samples, living organisms and natural observations, wet mount involve the suspend specimens in fluids such as water, glycerin, and oil immersion.
SMEAR SLIDE:- this require two flat plain slides which used to make a smear of a samples either a thick or thin by using the edge of other slide .
Slide come in to different forms that is borosilicate glass slide or plastic slide
PROCEDURE OF DRY MOUNT PRPARATION
Collect a free glass slide with cover slip
Position a thin slide section at the center of the slide
Cover the sample with cover slip
Observe under microscope.
PROCEDURE OF WET MOUNT PREPARTION
Place a drop of fluid at the center of the slide by using wire loop or dropper
Add one or two drop of the sample at a center
Lower the cover slip slowly avoiding air bubbles.
Remove excess water with paper towel
Observe under microscope.
PROCEDURE OF SMEAR PREPARATION
Place a liquid sample such as blood on to a slide
Using the edge of the second slide, slowly smear the sample creating a thin smear.
A low the smear to air dry
Cover the smear with staining solution for 2-3minute
Wash the staining solution with water and a low to air dry
Observed under microscope.
PRINCIPLE AND PRACTICE OF STERILIZATION
Sterilization: - this referring to any process that eliminate or kill all form of micro bid life, including transmissible agents such as (Bacteria, fungi, viruses, spores, forms etc.) that are preset on a surface such as laboratory apparatus, surgical material and biological culture media etc.
TYPES OF STERILZATION
Dry Heat Sterilization: - this is achieved by the use of hot air oven in which the materials are heated at certain temperature by electricity or gas, temperature is up to 3000c can be achieved. It is usually use for glass wires such as test tube, petri dishes, glass slide etc. it can also use for sterilization of materials such as powder, oil, which cannot be autoclave.
Moist Heat Sterilization: - autoclave is a chamber with a device which permits to be filled with saturated steam and maintain at a required temperature a time. This is used for sterilization of material such as culture media, needles, lancet etc. sterilization by autoclave is usually at a temperature of 1210c for 15 ___ 30minuts at pressure 15 ib is usually achieved by the used of pure steams.
Filtration: - some material particularly biological fluid such as serum or solution of substance like enzymes and some vitamins or antibiotics are destroyed if subjected to heat for any length of time. Filters of various spore sizes are used to filter or separate cells, larger viruses, bacteria and certain other microorganisms from the liquid in which they are suspended. A cotton plug in a test tube, flask or pipettes a good filter or preventing microorganisms.
Radiation: - the most commonly used kind are ultraviolet light, gamma rays and high energy electron radiation. This method is used to sterilize air surface and materials specially heat sensitive ones. Ultraviolet light is useful for reducing the number of microorganism in the air. X __ rays, gamma and beta rays of certain wavelengths from radioactive materials may be lethal or cause mutation in microorganism and tissue cells, because they damage DNA and proteins within those cells. Radiation can be used for the prevention of food spoilage, preparation of vaccines and treatment of cancer.
Chemical: - chemicals are more often employed to control or prevent the growth of microorganism. Some of the major group of chemical Antimicrobid agents include:
Phenol and phenolic derivatives e.g. Hexachlopane, coesols, Chloroxylenoletc.
Alcohols: - this is made in difference concentration between 50% ___ 70% is effective against vegetative cells.
Halogens: - chlorine and iodine are important Antimicrobid, Impochloriteor calcium Impochlorite. Iodine is a highly effective Bacteriacidalagent, and highly fungicidal and mix with alcohol solution to produce tincture.
Acid and Alkalis: - in general strong alkalis are more effective in gram negative and gram-positive bacterial and virus or protozoa.
Aidhydes:- such as Glutaraldehydes have a wide Microbicidal activity are Sporicidal and Fungicidal.
CULTURING TECHNIQUES FOR MICROSCOPIC ORGANISM
Cultivation of microorganism in artificial environments called (growth) using culture media under laboratory condition. Many different forms of microorganisms can be cultured (grown) including viruses, bacteria, fungi, algae and protozoa some organism will not grow at all on artificial culture; these include obligate intracellular pathogens they must be inoculated into live animals. Embryonated chicken Eggs or cell cultures.
CULTURE MEDIA
A culture media is any substance containing nutrients that support the growth of microorganisms media is used in laboratory to support the growth is known as artificial media or synthetic media.
Culture media can be categorized as liquid or solid media; Liquid media e.g. nutrient broth, selenite F broth etc. solid media is prepared by the addition of a gas to liquid media. Culture media can also classified according to the way it is used:
Basic or General purpose media: nutrient agar, nutrient both Sabouraidsdextrose agar etc.
Enriched media: - Blood agar, Tryptonesoya media etc.
Enrichment media: - Selenite F Broth
Selective media: - Salmonella Shrgella, Macconkeyagar etc.
Differential media: - Macconkey Agar, Blood Agar etc.
INCULATION OF CULTURE MEDIA
Culture media are inoculated with specimens in a sterilized manner to avoid contamination. Inoculation of liquid media involves adding a position of the specimens to the media while for a solid or plated media involves use of sterile inoculating loop to apply a portion of the specimen to the medium.
METHODS OF ISOLATING PURE CULTURE
Isolation is the separation of particular organism from mixed population that exists in nature. There are variety of technique where by the different species in a natural specimens can be isolated and grown as pure culture. These technique include:
The Streaking Method: in this method a tiny portion of a specimen is placed on the surface of an agar medium and streaked or spread over the surface. After incubation distinct colonies will develop on the surface to the plate. Each isolated colony is the progeny of a single cell and hence a pure culture.
The Pour Plate Techniques: - this involves dilution of the specimen in tubes of liquid agar medium to obtained well isolated colonies. The medium is maintain in a liquid state at a temperature of 450c to permit a through distribution of inoculums within the medium. The medium is poured in to the Petridis and allow it to solidify and then incubated. After incubation it show decreasing number of colonies resulting from the dilution procedure.
THE CELL
Cell: - are the basic unit of life in the modern world, they are the smallest known world that perform all of life function. All living organisms are either single cell or are multicellular organism composed of many cell working together. The cell is divided into prokaryote and Eukaryotes. Prokaryotes are single cell organism Bacteria and archaebacteria are examples of Prokaryotic cells. While Eukaryotes are multicellular organisms, including the plant cell contains chloroplast, central vacuoles and other plastid whereas the animal’s cell do not.
FUNCTION OF CELL
A cell performs these function essential for the growth and development of an organism.
Provide support and structure
Facilitates growth mitosis
Allow transport of substances
Energy production
it Aids in Reproduction
STRUCTURE OF CELL
The cell structure comprises individual components with specific functions essential to carry out life’s process. These components include cell wall, cell membrane, cytoplasm, nucleus and cell organelles which comprise; (Nucleus, Nuclear Membrane, Chromosomes, Endoplasmic Reticulum, Golgi Bodies, Ribosome, Mitochondria, Lysosomes, Chloroplast and Vacuoles.
Diagram of Animals Cell
Diagram of Plan Cell
SIMILARITIES BETWEEN PLANT AND ANIMAL CELL
Both Plant and Animal cell have a nucleus and chromosomes.
The both have a vacuole however the animal cell have one or more vacuoles which are smaller than the plant.
Both have a cytoplasm, an Endoplasmic Reticulum, Ribosomes, Mitochondria and Golgi apparatus.
THE DIFFERENCE BETWEEN PLANT AND ANIMAL CELL
ANIMAL CELL PLANT CELL
Cell wall are absent.
Chloroplast are absent.
Animal cell are mostly round and irregular.
Animal cell have one or more small vacuoles.
Plastids are absent.
Cell wall are present (form cellulose).
Plant cell have to make their own food.
Plant cell have fixed, rectangular shapes.
Have one large central vacuole taking up to 90% of cell vacuole.
Plastids are present.
OSMOSIS
Is the movement of water molecules from a solution with a high concentration of water molecules to a solution with a lower concentration of water molecules, through a cell partially permeable membrane?
DIFFUSION
Movement of particles of liquid or gases from a region of high concentration to one of lower concentration.
PLASMOLYSIS
Is the process in which cell lose water in a Hyperion solution. The reverse process deplemolysis or cytolysis.
BRYOPHYTE
1. Are the group of seedless plant that are the closest extant relative of early terrestrial plant.
2. Are a group of plant species that reproduce via spores other than flowers or seeds?
3. Are non-vascular land plant -
The growth primary in damp environment-
All bryophytes have a dominant gametophyte stage in their life cycle.
e.g liverworts, mosses and hornworts
SOURCE OF BRYOPHYTE
Surface water, soil moisture, humidity, Arial environment stream bank, road courts, in or adjacent to water bodies
GENERAL COLLECTION OF PLANT SPECIMENS
Look for a branch with flowers and or fruits on it and collect a twig of a branch that has good leaves, flowers and or fruits.
Make at least 3-5 specimens per tree
Tag the specimens with a tag and write the collection number on the tag
Wrap the specimens in a newspaper and place in a collecting back
Measure the height of the tree and five notes of its habit, butters, bole, bark characters, exudates, branching and canopy.
Describe the general environment in which the plant was collected from, soil topography, forest type and elevation and Gps location.
If live material are collected, such as seed, rhizomes, cuttings or wildings for planting those should be tagged and given the tag number as that of the specimen voucher
If plant samples are collected for DNA studies, these materials should be place in to the sampling jas with silica gel and given the same voucher number
Equipment/Material
: - Small pocket knife
: - Small paper bags (3 – 5)
:-pencil/pen
: - X 10 hand lens or magnifies
: - field book
DISSECTION TECHNIQUES
DISSECTION is the dismembering of the body of a deceased animal or plant to study its anatomical structure. The hand on approach of dissection allow student to sea, touch and enclose the various or gang.
TECHNIQUES.
_Make sure you follow lab rules
_ When your given your specimen examine it carefully before
_ If your specimen it preserved in a fluid wash with ethanol before you begin your dissection. This prevent hair from damaging
_ When you’re ready to cut, go ahead make the cut, you’re not going to sew the animal back together and bring it back to life, so dig in learn something and have a little fun.
DICHOTOMOUS
A dichotomous key is a method of identification where by group of organisms are divided in to two categories repeatedly. Is the method or key to identify and classified objects (I. e people, animal, plant, bacteria) etc. in to specific categories base on their characteristics, the key use in biology to identify unknown organisms. .
When creating a dichotomous key based on qualitative and quantitative factors be consider.
QUALITATIVE
(Physical attributes
How the organisms look
Color it is etc.
QUANTITATIVE
Number of legs
Weight
Height
HOW TO MAKE A DICHOTOMOUS KEY
STEP 1 := List down the characteristics e. g for Animals you may notice that some have feather, legs long tails, don't etc.
STEP 2:= Organize the characteristics in order you need to start with the most general characteristics first, before moving to the more specific ones.
STEP 3:= Divide the specimens You can use statement ( I. e has feathers and no feathers) or question (does it have feather?) to divide your specimen in to two group.
STEP 3:= Divide the specimen ever feather - For e. g first you may have groped your animal as have feather and have no feathers, in which case one with feathers can be categorized as birds which you can further sub divided the one that have no feathers as having fur and having no fur continue to subside until you have identified and named all of them.
SEPT 5:= Draw a dichotomous key diagram
You can either create a text-based key or a graphic one where you can ever use image of the specimen you are trying to identify
STEP 6:- TEST it out - Ones you have completed you are trying to identify and go through the question in your dichotomous tree to see if you get it identified at the end if you think the necessary adjustments.
* Consider only one characteristics at a time.
* Use moss theological or observable characteristics as much as you can.
* Use major characteristics when diving the organisms in the beginning and use lesser or less obvious characteristics to divide them in to smaller groups.
* When writing contributing statements rely on similar word formats (I. e have feather and don't have feathers)
* Be specific in your statements and avoid re pleating the same characteristics.
E.g for plant
PLANTS
ARE THERE ROOT AND STEM
NO YES
ARE THE LEAVE
ARE THERE SEED
ALGEA
NO YES
BOYOPHATE
PTECIPHATE
ARE THE FOLLOWERS
GMNOSPERM
NO YES
ANGIOSPERM
E.G FOR ANIMAL
VETEBRETE
MAMMALS
DOES IT HAVE FETHER
YES NO
DOES IT HAVE FEATHER
BIRD
DOES IT HAVE DRY SKIN
yes
RAPTILE
DOES IT HAVE SCALE
NO YES
AMPHIBIANS
FISH
MEIOSIS
Is a type of cell division that reduces the number of chromosome that parent cell by half and produces four gamete cell. This process is required to produce egg and sperm cell for sexual reproduction
Meiosis can be divided in to nine stages. These are divided between the first time cell divided (melosisi)( i) and the second time it divided (meiosis ii)
Meiosis (i):- Interphase, prophase, metaphase, Anaphase, Telophase & Cytokinesis
Melosis (ii):- prophase, metaphase (ii), anaphase (ii), tolophase (ii) and cytokinesis.
Telophase (ii) & cytokinesis
Phase i: prophase: - this is when the genetic fibers with in the cell nucleus, known as chromatin, begins to condense and become tightly compacted together.
(Chromosomes line up along metaphase plate)
Metaphase
Phase 2:- One all the kinetochore microtubules get attached to the sister chromatids centromeres during prometaphase.
(Chromosome break at centromeres and move to opposite end of the cell)
Phase 3:- Anaphase; the centromeres at the clatter of the sister chromatids are severed.
{(Nuclear membrane reforms, nuclei reappear, chromosomes unwind in to chromatin)}
Phase 4: Telophase: When the newly separated daughter chromosomes get their own individual nuclear membranes and identical sets of chromosomes.
MITOSIS
Mitosis Is a process where a single cell divides once in to two bidentical daughter cell. During mitosis one cell divides once to from two identical cell. The major purpose of mitosis is for gmoth and to replace worn out cells.
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