TOPIC ONE: INTRODUCTION TO BIOLOGY

INTRODUCTION TO BIOLOGY

Basic Concepts and Terminologies of Biology

Biology

Biology is derived from two Greek words, that is, bios which means life and logos or logia which means study or knowledge.

So biology can be defined as a branch of science which deals with the study of life. The term biology can also be defined as a branch of science which deals with the study of living things or organisms.

Biologist

A person specialized in the study of biology

Life

Life means being alive or existing. Something is alive or existing if it possesses life processes. The life processes are growth, movement or locomotion, respiration, excretion, reproduction, sensitivity and nutrition.

Organism

Organism is anything which has life. It is the other name of a living thing. Organisms are made up of cells.

Cell

A cell is a basic unit of living things. The cell has three main parts, cell membrane, cytoplasm and nucleus. Cells which make up plants are called plant cells and those which make up animals are called animal cells.

Some organisms are made up of one cell. They are called unicellular or single-celled organisms e.g. amoeba, euglena and yeast. Some organisms are made up of many cells, they are called multi cellular organisms e.g. animals, plants, and most fungi.

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	Physical 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

It helps a man to understand himself/herself better
Knowledge of biology enables human being to conserve the environment.
It helps man to evaluate environment uses such as pollution, global warming and environmental degradations.
Biology help to understand cause, symptoms, method of transmission, prevention, and treatment of diseases this improve the standard of living.
It provides answer to fundamental questions.
It helps us to enter in careers such as medicine, agriculture, reproductive, health and genetic Engineering.
Biology helps us appreciate nature

THE RELATIONSHIP BETWEEN BIOLOGY AND OTHER SUBJECT FIELD

Biology related to many other field of study such as agriculture, medicine, pharmacy such as veterinary, medicine and nutrition.

AGRICULTURE

Biology research finding on crops and livestock have led to improve agriculture production.

MEDICINE AND PHARMACY

Medicine is the study of prevention and treatment and cure of disease.

NUTRITION

Biology is used by dieticians to determine the kind of diets suitable for people with different health problems.

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;

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.

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.

SENSITIVITY/ IRRITABILITY

It is the ability of an organism to detect and respond to a change in its environment

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 involve 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.

REPRODUCTION

Is the process where by living things give 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;

The eyes for seeing
The nose for smelling
The ears for hearing
The tongue for tasting
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	Second (s)
Length	Ruler	Meter (m)
Temperature	Thermometer	Kelvin (K) - Degrees Celsius -Degree Fahrenheit

In biological investigation like in any other scientific research, methods are listed. The scientific method is a set of steps that scientist use 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 today 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 experiment 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

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Observation and data collection

The scientists observe 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 analyses 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 taste 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, 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;

Do not go into the laboratory in the absence of a teacher or laboratory technician.
Do not handle or use apparatus, chemicals or specimens in the absence of a teacher.
Do not taste/ eat substances during experiment
Know the location of all exits
Do not leave experiment unattended
Turn off gas and water taps when not in use
Do not burn substances towards other people in the laboratory
Do not take laboratory equipments, chemicals or specimens out of the laboratory
Do not play or run in the laboratory
Read the labels or containers before using the contents. Do not interchange label.
Dispose all waste materials after all experiment.
After each experiment clean all the equipments you have used
Avoid touching yourself while performing experiment, clean your hands with soap and water after Experiment.
Do not touch electrical equipment with wet hands.
If you don’t understand something ask your teacher.
Know the location and operation procedure of all safety equipment e.g. First aid and fire extinguishers.
Dress properly for laboratory activities, tie back long hairs. Do not wear dangling Jewelers, Sandals. Shoe must cover a leg completely.
Report all accidents immediately to your teacher or technician
Never use dirty, chipped or cracked equipment.
Handle live spacemen carefully. if an animal bites or insect stings you, report the accident to your teacher

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 a 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.

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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.

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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

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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.

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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.

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FLAMMABLE
These are substances which can catch fire easily. The substances should never be brought near open flammable
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BIOLOGY APPARATUS

Biology apparatus are the tools and equipments 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 a source of heat
10.	Dropper	Used to add liquid during experiment
11.	Spatula	Used for taking some substance from the container
12.	Test tube holder	Used to hold test tube
13.	Test tube	Used to hold and heat chemicals
14.	Test tube rack	Storing test tube
15.	White tiles	Used to put specimen during experiment that involve colour changes
16.	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) Electron microscope

Light microscope can magnify object up to 2000 times. This is the type of microscope that is commonly used in school laboratory.

Electron microscope can magnify a specimen up to 50000 times.

PARTS OF A LIGHT MICROSCOPE AND THEIR FUNCTION

1)	Eye piece	Has a lens which magnify specimen
2)	Body tube	Support the objective revolving nose piece
3)	Rotating nose piece	Support the objective lens
4)	Objective lens	Magnify the specimen under observation.It has three lenses, lower power, medium power and high power
5)	Course adjustment knob	Raises or lowers the body tube in order to bring the image into focus
6)	Arm	Support the body tube, knobs, stage diaphragm and mirror. It’s one of the part which is held when moving the microscope
7)	Fine adjustment	Raises or lowers the body tube in order to bring the image into sharp focus
8)	Ocular tube	The tube allow light to pass straight from the objective lens to the eye piece lens

THE STRUCTURE OF THE LIGHT MICROSCOPE

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How to use light Microscope

Place the microscopes on the laboratory bench or table make sure it’s not near the edge.
Mount the specimen on a microscope slide, cover it with the cover slip.
Make sure that the low power objective lens is on line with the eyepiece lens.
Place the slide with the specimen on the stage.
While looking through the eyepiece, use your hand to adjust the stage so the light is directed at the specimen on the stage.
Adjust the course adjustment knob to bring the specimen focus.
Adjust the fine adjustment knob to bring the specimen into sharp focus.
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

Turn the adjustment knobs slowly, always start with course adjustment knob.
Always lift microscope using both hands, one hand holding the arm and other holding the base.
When not in use cover the microscope with clean cloth and store it in a dry, dust free space
Clean dirty lenses using lens tissue or soft cloth.
Don’t place the microscope at the edge of the table or bench as it could be knocked over.
When not in use for a long time remove the lenses and put them in desiccators.
Don’t touch the microscope with wet hands
Don’t touch the surface of the mirror of the lens with your fingers.
Lubricate moving parts regularly.
Always use a cover slip in order to protect the lens of the microscope from the substances in the specimen.
Remove the slides from the stage immediately after use.