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 LIFELife 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 BIOLOGYThere 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;
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....................... 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 head-wear 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 SYMBOLSThese 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 ............................
THE MICROSCOPE
The microscope is an instrument used to magnify very small specimen so that can be seen clearly.
THERE ARE TWO TYPES OF MICROSCOPE1. 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.
