INTRODUCTION TO
BIOLOGY
What is biology?
Biology is study of living things or organism.
Living things include bacteria, fungi, animals, pants etc.
Biology is derived/comes from two Greek words;
Bios –
means “Life”
Logos – means “study”
The people who study biology are called Biologist. Very
small organisms are microorganism. The simplest living things are made up of
one cell these are called unicellular organism e.g. bacteria, protozoan and
amoeba (also called microscope organism). Large organisms are made up of many
cells
These are called multi-cellular organism e.g. fish, trees,
man.
WHAT IS LIFE
Life is the state of living thing which plants, animals, and
other living organisms have before they die.
The basic unit of life is cell. All living things are made
up of cell, cell are so small that they cannot be seen with naked eye.
BRANCHES OF BIOLOGY
There are two main branches of biology
1.
Botany – study of plants
2.
Zoology – study of animals only
However there are many minor branches of biology. That deal
with different aspects of living things
Example;
BRANCHES
|
AREA OF STUDY
|
1.Anatomy
|
Physics structure of organisms
|
2.Cytology
|
Deals with cell
|
3.Ecology
|
Relation between organisms and their environment
|
4.Mycology
|
Deals with fungi
|
5.Taxonomy
|
How organisms are named and groups
|
6.Physiology
|
How organisms body parts function
|
7.Parasitology
|
Deals with parasites
|
8.Immunology
|
The body defense against infections and disease
|
IMPORTANCE OF STUDYING BIOLOGY
1.
It helps a man to understand himself/herself
better
2.
Knowledge of biology enables human being to
conserve the environment.
3.
It helps man to evaluate environment uses such
as pollution, global warming and environment degradation's.
4.
Biology help to understand cause, symptoms,
method of transmission, prevention, and treatment of diseases this improve the
standard of living.
5.
It provides answer to fundamental questions.
6.
It helps us to enter in careers such as
medicine, agriculture, reproductive, health and genetic engineering.
7.
Biology helps us appreciate nature.
THE RELATIONSHIP BETWEEN BIOLOGY AND OTHER SUBJECT FIELD
Biology related to many other field of study such as
medicine, agriculture, pharmacy such as veterinary, medicine and nutrition.
1.
AGRICULTURE
Biology research finding on crops and livestock have led to
improve agriculture production.
2.
MEDICINE AND PHARMACY
Medicine is the study of prevention and treatment and cure
of disease.
3.
NUTRITION
Biology is used by dieticians to determine the kind of diets
suitable for people with different health problems.
4.
FORESTRY
Biologists have developed varieties of trees that grow well
in dry areas, also that mature fast so as to prevent desertification.
CHARACTERISTICS OF
LIVING THINGS
Living things have characteristics which make them different
from non – living thing. These are;
1.
NUTRITION/FEEDING
All living things take in food or make their own food. Food
enables living things to grow, develop and carry out on life process.
2.
RESPIRATION
Respiration is a process by which food substances are broken
down to produce useful energy in a cell.
3.
EXCRETION
Is the process by which excess waste or harmful material
resulting from the chemical reaction occur in body cell are removed out of
body.
4.
SENSITIVITY/IRRITABILITY
It is the ability of an organism to detect and respond to a
change in its environment.
5.
GROWTH
Growth is an increase in size and mass of an organism that
becomes more complicated and more efficient.
6.
MOVEMENT/LOCOMOTION
Is an action of changing posture or position of an organism.
Movement which involves the whole body is called locomotion. E.g. Animals but plants just show movement in term
of growth of their body parts. E.g.
Roots, shoots and leaves.
7.
REPRODUCTION
Is the process whereby living things gives rise to new individuals
of their own kinds. This ensures that there is continued existence of the
species and life forms.
Non – living
things are referred to as inanimate.
Living things
are referred to as animate.
SCIENTIFIC PROCESS IN BIOLOGY
Biology is a practical science that involves carrying out
experiment, observation, measuring and experimentation are skills that we need
when studying Biology, and we use our sense organs to make observation.
These organs are;
1.
The eyes for seeing
2.
The nose
for smelling
3.
The ears for hearing
4.
The tongue for tasting
5.
The skin for feeling
Scientific measurements are taken using specific instrument
and units.
Some basic biological
measures are
MEASURE
|
INSTRUMENT
|
SI UNIT
|
Mass
|
Beam balance/Digital balance
|
Kilogram(kg)
|
Time
|
Watch
|
Seconds(s)
|
Length
|
Ruler
|
Meter(m)
|
Temperature
|
Thermometer
|
Kelvin(k) – Degree Celsius or Degree
Fahrenheit
|
In biological investigation like in any other scientific
research, methods are listed. The scientific method is a set of steps that
scientific used to study things.
Those methods are;
1.
Problem identification.
2.
Formulation of hypothesis.
3.
Experimentation.
4.
Observation and data collection.
5.
Interpretation of data.
6.
Conclusion.
Problem identification
In day to day life one time comes across question which
require explanation or problem which needs solution or something to prove e.g.
it is observed that buffaloes in Serengeti park are dying at great rate what
would be the cause of death or there is poor harvesting or Earth warms are
mostly found in the soil wells handed are as why?
Formulation of hypothesis
A hypothesis is a suggestion of the answer to the question
asked. It is an intelligent guess that tries to explain as an observation for
example Earth worms prefer shaded areas because in the soil shaded there is
more moist. A hypothesis can’t be termed as a biological acceptable to explain
action. Therefore experiment should be designed, proved or disapproved. If
hypothesis is correct we say it is accepted, if disapproved we say rejected.
Experimentation
An experimentation is a test that is carried out under
controlled conditions to determine whether a hypothesis is correct or not. In
any experiment there is control experiment and experiment test. Example of
experiment; Earth worms prefer moist or dry condition.
Observation and data collection
The scientist observes what happens from the time the
experiment was set up to the time it ends. It is important to note all the changes
made from the beginning to the end of the experiment and recording.
Interpretation of data
At the end of experiment the scientist analysis the
observations and data recorded. The
scientist may look for pattern or in the data.
Conclusion
A conclusion is a statement that summarizes what a scientist
has learnt from an experiment. When scientist read conclusion, they test
whether the data or information collected support the hypothesis (accepted) or
not support the hypothesis (reject), if so another hypothesis must be
formulated and repeat the whole experiment.
BIOLOGY LABORATORY
A laboratory is a special room designed for carrying out
scientific experiment. A biology laboratory is a special building designed for
carrying out biological experiments. A laboratory should have adequate space
for carrying out experiment, proper lighting, good ventilation, source of
water, and means of heating and adequate space for storing apparatus, chemicals
and specimens.
LABORATORY RULES
In biology laboratory we use hazardous chemical, fragile
equipment or dangerous specimens. For this reason, it’s important to follow a
certain rules and regulation for our safety and safety for others.
These rules are;
1. No food or drink is allowed
in any biology lab. No gum chewing. No putting on of makeup. Lunches,
thermoses, and water bottles can be stored inside backpacks or purses. They are
not allowed on lab benches, the floor, near computers, or in sinks. Coffee cups
are not allowed in the teaching and research labs
2. Be polite- no pushing,
shoving, fighting or horseplay.
3. Always wear goggles when you
work with chemicals, hot liquids, or other materials that could harm you. Use
caution when working with organic solvents if you wear contact lenses
(especially soft lenses) – if you’re in doubt about what chemicals you’re
working with ask the instructor.
4. Wear gloves while working in
the laboratory – gloves are not provided- you must purchase examination
gloves yourself. Gloves are available for purchase at the campus bookstore.
Please let us know if you have an allergy to latex.
5. If you have allergies or asthma or
think you might be pregnant please inform the instructor.
6. Always wear closed toed
shoes and long pants or a long skirt during labs to protect your legs and feet
from spills.
7. Always alert your teacher to
any spills on your skin or clothing.
8. Never taste or smell ANY
chemicals unless your teacher tells you it is safe to do so.
9. Tie or pin long hair,
scarves and headwear out of the way to avoid contact with flames or chemicals.
10. Be sure you know how to use
equipment before beginning an experiment. If you are unsure - ask!
11. Children are not allowed in
the laboratory. There are too many hidden dangers for young people.
12. Mouth pipe ting or drinking of
solutions is strictly prohibited.
13. Broken glassware or sharp
metal pieces should be placed in “sharps” boxes (also labeled “broken glass”)
unless it is contaminated with body fluids or microorganisms. Contaminated
sharps should be placed in an appropriate labeled metal or glass container for
sterilizing.
14. Organic fluids (e.g.,
ether, acetone, chloroform) or other volatile liquids should be used inside
a fume hood.
15. Chemical wastes should
never be placed in a sink drain without permission. Please consult your
instructor in all cases.
16. Media with microorganisms (liquid
or solid) should be placed in a Biohazard bag or labeled autoclavable beakers
for sterilizing and disposal.
17. All glassware should be
rinsed after use and test tubes placed upside down in the racks provided.
Slides and covers lips should be discarded.
18. Students and instructors should
know the locations and operation of all safety equipment. This includes
fire extinguishers, eye washes, body showers, first aid kits, and the
nearest exit from their room.
Distinguishing the biology laboratory
from other facilities
The biology laboratory is different
from other school facilities such as classroom, library or physics and
chemistry laboratory.
A class room has desk and chairs,
students are taught in a class room.
A library has variety of reading
materials some libraries have tables and chairs where we can sit and read.
A biology laboratory has models,
specimens, cage, aquaria and chart which may not be in physics or chemistry laboratory.
Some of unique things found in
biological laboratory are preserved specimens of organisms such as insect,
micro organism and plants.
WARNING
SIGNS/SAFETY SYMBOLS
These are warning signs that are found
on apparatus and chemical containers in the laboratory. Some may be found in or
on the boxes used to hold either chemicals or apparatus. These signs must be
obeyed in order to ensure safety in the laboratory before one uses a chemical, one
should know whether that chemical is Toxic, Corrosive, Flammable, Oxidant,
Explosive, Harmful or Irritant.
TOXIC
Toxic substances are dangerous and may cause death
immediately or after few days. When handling toxic substances one should be
very careful. In case a chemical gets into contact with your skin it should be
washed out with a lot of water.
CORROSIVE
Corrosive substances can burn one’s skin. They can cause
blindness in case they come into contact with the eyes. Example of corrosive
are sulphuric acid, hydrochloric acid, nitric acid, and concentrated alkalis
e.g. Sodium hydroxide, potassium hydroxide, ammonium hydroxide.
FLAMMABLE
These are substances which can catch fire easily. The substances
should never be brought near open flammable.
OXIDANT
These are chemical that can accelerate burning in the presence
of an oxidizing agent; a small fire can be made bigger. Example in the heating
of potassium permanganate mixed with saw dust.
EXPLOSIVE
An explosion is a forceful rapid reaction, which involves
throwing off of particles at high speed. Chemicals carrying the sign of
explosive may cause explosion if not handled carefully and according to the
instruction.
HARMFUL/IRRITANT
These are chemicals which can make you sick but it does not
kill you, it can cause illness. This substance may not kill immediately, but
may have effects after long exposure.
BIOLOGY APPARATUS
Biology apparatus are the tools and equipment's needed in
order to study biological experiments effectively.
APPARATUS
|
USES
|
Hand lens
|
Used to magnify specimen/object
|
Sweep nets
|
Used to catch small flying organisms e.g. butter flies, housefly
|
Fishing nets
|
For catching fish and aquatic animals
|
Petri – dish
|
Is a shallow glass where specimen are put for close observation
|
Mortar and pestle
|
Is small hard bowl used for crashing or grinding substances
|
Crucible
|
Is a container in which substances are heated to very high
temperature
|
Thermometer
|
Used to measure temperature
|
Dissecting Kit
|
Is a kit that contain all tools for making dissection of specimen
|
Spirit – burner
Bunsen - burner
|
Used as source of heat
|
Dropper
|
Used to add liquid during experiment
|
Spatula
|
Used for taking some substance from the container
|
Test tube holder
|
Used to hold test tube
|
Test tube
|
Used to hold and heat chemicals
|
Test tube rack
|
Storing test tube
|
White tiles
|
Used to put specimen during experiment that involve colour changes
|
Watch glass
|
Is a shallow dish that used as evaporating surface or cover for
beaker
|
THE MICROSCOPE
The microscope is an instrument used to magnify very small
specimen so that can be seen clearly.
THERE ARE TWO TYPES
OF MICROSCOPE
1.
Light microscope
2.
Electronic microscope
Light microscope can magnify object up to 2000 times. This is
the type of microscope that commonly used in school laboratory.
Electronic microscope can magnify a specimen up to 50000
times.
PARTS OF A LIGHT MICROSCOPE AND THEIR FUNCTION
Eye piece
|
Has a lens which magnify specimen
|
Body tube
|
Support the objective revolving nose piece
|
Rotating nose piece
|
Support the objective lens
|
Objective lens
|
Magnify specimen under observation. It has three lenses, lower power,
medium power and high power
|
Course adjustment knob
|
Raises or lower the body tube in order to the image into focus
|
Arm
|
Support the body tube, knobs, stage diaphragm and mirror. It’s one of
the part which is held when moving the microscope
|
Fine adjustment
|
Raises or lowers the body tube in order to bring the image into sharp
focus
|
Ocular tube
|
The tube allow light to pas straight from the objective lens to the
eye piece lens.
|
THE STRUCTURE OF THE LIGHT MICROSCOPE
How to use light Microscope
1.
Place the microscope on the laboratory bench or
table makes sure it’s not near the edge.
2.
Mount the specimen on a microscope slide, cover
it with cover slip.
3.
Make sure the low piece objective lens is on
line with the eye piece lens.
4.
Place the slide with the specimen on the stage.
5.
While looking through the eye piece, use your
hand to adjust the stage so the light is directed at the specimen on the stage.
6.
Adjust the course adjustment knob to bring the
specimen focus.
7.
Adjust the fine adjustment knob to bring the
specimen into sharp focus.
8.
Rotate the nose piece to a lighter power
objective lens if you want to observe more details on the specimen.
How to care for light Microscope
1.
Turn the adjustment knobs slowly, always start
with course adjustment knob.
2.
Always lift microscope using both hands, one
hand holding the arm and other holding the base.
3.
When not in use cover the microscope with clean cloth
and store it in a dry, dust free space.
4.
Clean dirty lenses using lens tissue or soft
cloth.
5.
Don’t place the microscope at the edge of the
table or bench as it could be knocked over.
6.
When not in use for a long time remove the
lenses and put them in desiccators.
7.
Don’t touch the microscope with wet hands.
8.
Don’t touch the surface of the mirror of the
mirror of the lens with your fingers.
9.
Lubricate moving parts regularly.
10.
Always use a cover slip in order to protect the
lens of the microscope from the substances in the specimen.
11.
Remove the slides from the stage immediately
after use.
