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Is a scientific study which deals with living things or organisms. Living things or organisms mean:
Biology is derived from two Greek words:
Note:All living things are made up of cells. Unicellular organisms -> Single celled e.g. Amoeba are multicellular organisms with many cells.
A cell: Is a single unit of life.
Cell -> tissue -> organ -> system -> organism.
Characteristics of living things.
Note the following:
Simple structure of animal and plant cell.
Functions of cell parts.
|Plant cell||Animal cell|
|1. Has definite shape.||Has no shape (irregular)|
|2. Has a cell wall made up of cellulite.||Has no cell wall.|
|3. Has a large permanent vacuole.||Has a small and temporary vacuole.|
|4. Has chlorophyll.||No chlorophyll.|
The importance of studying biology.
The relationship between Biology and other related science subjects.
Biology tells us about living things and Chemistry tells us about the composition of living things.
2. Biology and Physics.
In Biology we learn names and shapes of different organisms and in physics we describe the quantity of matter in organisms.
3. Biology and Mathematics.
An organism can be measured to check body temperature, blood sugar, obesity, blood pressure etc. All these are done due to mathematical skills.
4. Biology and Geography.
Geography provides the information about the home of living things.
The following are the methods of studying Biology.
1.Observation (Identification of a problem.)
This process involves the following sense organs: eyes, ear, nose, skin and tongue. But the tongue is rarely used because some of the chemicals are poisonous.
Involves a guess work so it can be regarded as a biological acceptable explanation of what has been observed unless more proof takes place.
Is designed to prove or disprove formulate of hypothesis. This work is done in the laboratory.
4.Observation and data recording.
At this level, we observe and record important events which appear to be important or meaningful.
5.Interpretation of data.
At this level obtained are clearly explained in relation to the purpose of the experiment.
At this level, the researcher is either confirming or rejecting the hypothesis formulated.
Measurements:During experiments in order to observe clearly an instrument called microscope is used.
Microscope: Is an instrument used to magnify images of near objects to a large size.
Parts of a microscope.
The power is indicated on the objectives as X5, X10, X40 etc.
Note- X means multiply.
Laboratory is a room or a building specially designed for biological experiments.
Types of laboratories.
A good lab must have:
Safety in Biology lab.
When an experiment is done, it should never be assumed to be completely harmless. Even the apparently simple experiments should be regarded as a potential source of danger.
Toxic- It can poison you.
Common tools used in studying Biology.
Common chemicals used in Biology.
Specimens used in Biology.
Models used in studying Biology.
It is an immediate and temporary care or help or treatment given to an injured person before taking him to the hospital.
Importance of First aid.
A First Aid kit.
Is a small box or instrument in which all medical facilities for conducting First aid are kept.
Components of first aid kit.
First aid given to victims of:
Safety in our environment.
Environment is the surroundings in which living things live. It includes natural world such as land, air and water in which people, animals and plants live. Humans have invented methods to protect themselves against the diseases in their environment.
Personal hygiene and good manners.
-Personal hygiene is defined as the measures each individual employs to keep in good physical precautions.
-Good manner is a way of behaving that is considered acceptable in your family.
Principles of personal hygiene and good manners.
It integrates the following:
a.) Hand hygiene.
Hands should be washed especially after contact with an animal, after using a towel, before eating or after touching a person likely to be infected. A good routine for washing hands should include:
A dirty body is a hotbed for developing germs. Dust, warmth, sweat and other secretions are all factors which encourage germs to multiply. It is recommended to bath at least twice a day, and oil properly. Keep your hair short and comb to maintain its cleanliness.
c.) Oral hygiene.
Attention should be paid to eliminate food particles. To avoid dental plague, ensure daily gum care as well as visiting the dentist regularly. Adhere the following to maintain oral hygiene:
d.) Nasal hygiene.
Nasal secretions are highly contaminated and a running nose or sneezing is a important source of germs disseminations. Frequent nose blowing to clear the nostrils using paper tissues is done as follows:
e.) Cleaning clothes and shoes.
Clean clothes, underwear and shoes should be worn and changed daily.
f.) Doing physical exercise.
How does physical exercise help us live longer and better?
g.) Environmental cleanliness.
Proper cleaning of the house or room is very important to keep you healthy. It includes:
In summary, the following are eight personal hygiene practices:
What is the behavior of an individual with good manners?
Good manners should be acceptable in one’s culture.
Tanzanian culture, good manners include:
Importance of personal hygiene and good manners.
It is very important to maintain personal hygiene and good manners because:
-They maintain health.
-All individuals will be respected and loved.
-All individuals will attain development.
-Avoid risk behavior.
Safety at home and school.
Safety is freedom, danger or injury.
Accident is an unexpected event.
Common accidents at home and school.
-Snake or insect bites.
-Getting hurt by sharp objects.
-Bone fractures and dislocation.
Poison is a substance that causes injury or death when swallowed. It causes from different sources such as:
-Taking the wrong dosage of the prescribed medicine.
-Eating contaminated food or water.
-Rat poison, bleach, detergents etc.
It is the destruction or damage caused by fire or heat. Burning can be caused by:
-Chemicals which are flammable.
c.) Insect or snake bites.
There are poisonous snakes and insects that are harmful. The poisons from black mamba, cobra, scorpions, bees and wasps are harmful to human health.
d.) Broken or dislocated bones and cuts.
The following can cause these:
-Getting hit by objects such as stones, bricks, wood, trees etc.
Ways of preventing accidents (Home and school.)
-Children must be protected from falls, burns, poisoning and electric shocks.
-People should learn road rules and traffic signs.
-Things which may cause accidents e.g. Such as kerosene, fuel, medicine, chemicals etc. should be locked.
-Extinguish all glowing residues before disposal.
-Use the right fuel for the right burners e.g. Do not use petrol for a kerosene burner.
-Cool a burner completely before you refill it with a liquid fuel.
-Electric circuits should be used as per instructions.
-Avoid spraying insecticides near flames as they are flammable.
-Wastes should be well and properly handled.
-Never keep kerosene, petrol or other poisonous substances in a soft drink bottle.
How to keep peace and safety at home.
-Toxic materials should be kept at a safe place.
-Smoking, drinking alcohol and other risky behaviors should be avoided.
-Furniture and cooking utensils should be well arranged.
-Food has to be well prepared.
-Decision making should involve the majority.
-Assertive behavior is essential.
Waste is any material without use, rejected, worthless or unwanted.
Waste comes from various activities such as:
-Construction wastes: Wood, metal, bricks, plaster, glass etc.
-Agricultural wastes such as pesticides, herbicides, empty containers.
-Industrial wastes – waste water, sludge, metals etc.
Types of waste.
Contain less than 70% of water.
They include household garbage, residual solids, mining wastes and oilfield cuttings.
Contain less than 1% of solids.
They include: wine, waste water, used chemicals and liquid industrial waste. They may contain a high concentration of dissolved salts and metals.
This is a class of water between liquid and solid. They usually contain between 3% and 25% solids while the rest of the material is water-dissolved material.
They include: Carbon dioxide, sulphur oxide, carbon monoxides, fluoride gas and nitrogen dioxide.
Waste should not be disposed in such a manner that the public interest is not impaired.
What is waste disposal?
It can be defined in different ways.
Principles of waste disposal.
Principles of disposing hazardous and non hazardous waste differ. Hazardous waste is of two types:
Non hazardous wastes are those that pose no immediate threat to human health (and the environment.) (Household garbage.)
General principles of waste disposal.
Why not burn waste?
-May cause air pollution
-Some waste may burn to ash.
Why not bury waste?
-It may contaminate soil or water.
Proper ways of waste disposal.
Recovery-Turn materials into other categories e.g. cow dung -> biogas.
Recycling-Brings items to a stage where they will turn to other items.
Reduction of use-This is the basic principle of sound waste management.
Safe waste disposal-Waste should be disposed in a safe area.
Classification of waste based on recycling.
Waste falls into two main groups:
a.) Recycled waste:
Can be used to manufacture new products.
b.) Non recycled waste:
Cannot be used to manufacture new products.
Importance of proper waste disposal.
Waste should not be disposed in such a way that:
Thus proper waste disposal is important because:
Effects of poor waste disposal.
Is a physical, mental and emotional well being of a person. Including freedom from hunger and anxiety.
Importance of good health.
Is the ability of the body to fight against diseases.
Types of immunity.
Is an immunity which an individual is born with.
Types of immunity:
Is an immunity which develops as a result of exposure to pathogens e.g. when a person recovers from chicken pox or red eyes e.t.c.
Occurs when antibodies are transferred from one person to another. This occurs naturally between the mother to an infant in breast feeding. This ends when the baby’s own immune system has matured.
Is a process of introducing vaccine into the body of an organism in order to increase the ability of the body to produce antibodies which fight diseases.
Is an antigen which triggers the body to produce antibodies.
Vaccine can be made of:
Examples of diseases which can be vaccinated:
The cells and tissues involved in make up of the immune system includes:
Factors which affect body immunity:
Infections and diseases.
Infection:Is a disease caused by an organism.
Pathogen:Is an organism which can cause a disease e.g. Virus.
Vector:Is an organism that transmits diseases causing micro organisms.
Host:Is an organism in which a pathogen lives e.g.. Human beings.
Parasite:Is an organism which lives in the body of another organism.
Disease:Is the body condition other than injury that interferes with the normal functioning in the body.
Are diseases that are transmitted from one organism to another, e.g. Cholera, T.B e.t.c.
Causes of diseases.
Types of diseases:
Other communicable disease require isolation (Quarantine) yellow fever, cholera, small pox, plague, SARS e.t.c.
Is a disease which spreads quickly and affect a large number of people in an area over a short period of time. E.g, measles, cholera, meningitis e.t.c.
Is a disease that affects the large area like several countries at a time, even a whole continent e.g. HIV/AIDS.
Is a disease that is always found in a certain area continuously. E.g, Bilharzia, malaria e.t.c.
They are non-infectious diseases that cannot be spread from one person to another.
They are caused by:
It includes kwashiorkor, marasmus, scurvy e.t.c.
It includes sickle cell anemia, color blindness, albinism e.t.c.
It includes goiter, diabetes mellitus e.t.c.
It includes asthma, cancer, allergy e.t.c.
Common human diseases
It is caused by a bacterium called Vibrio cholerae. The bacterium affects the alimentary canal. It strikes areas where they are poor sanitary conditions and the water is poorly treated. It is epidemic during wars and famine.
When bacterium is ingested, it multiplies in the small intestines and invades the epithelial cells. When the bacteria die, they release toxins that irritate the intestine lining and leads to the secretion of large amounts of water and salts with the following symptoms:
-Diarrhoea and eventual vomiting.
-Body temperature drops.
-Loss of weight.
-Fast and shallow breathing.
Hygienic waste disposal and keeping food and water supplies clean are the control methods of this disease. Food should be well cooked and water must be boiled. Using toilets and washing hands frequently. One going to an infected area must be vaccinated.
Antibiotics will kill vibrios but it is more important to restore the salt and water balance of the body by drinking a solution made by dissolving one teaspoon of sugar and a pinch of salt in water. A vaccine made from the killed bacteria will give immunity for 3-6 months.
It is the infection of the membrane. There are three types of meningitis:
Symptoms:Bacterial meningitis is the most common associated with nausea, vomiting, headache etc.
Prevention:People carrying diseases should not mix with others.
Treatment:Early treatment is necessary for bacterial meningitis. Penicillin treats meningitis.
It is a bacterial disease called by bacillus bacterium called Pesturella pestis.
Symptoms:The person develops fever, swelling and inflammation of lymph nodes. Often the patient bleeds severely in many parts of body.
Transmission: Bubonic plague is caused by a bacterium and transmitted from infected rats to man by bite of fleas that feed on both.
Treatment: It can be treated using antibiotics such as tetracycline and streptomycin.
Caused by a bacterium known as Salmonella typhi. It is expelled from body by urine and stool.
Transmission:It spreads through contaminated food and water.
Symptoms:Body aches, fatigue, abdominal pains, diarrhoea, vomiting and constipation.
Since infection can occur only by ingesting the bacterium derived from the faeces or contaminated water, the long-term ways of control are to dispose human waste safely, ensure water is treated and keeping food safely. The hands should be washed frequently after using the toilet and before eating food so that intenstinal bacteria cannot be taken in with the food. Fruits should be wash using clean water.
Treatment:It is treated using an antibiotic called chloroamphenical.
It is also called schistosomiasis. 200 million people around the world are infected with this disease. It is characterized by irritation in the rectum or urinary bladder. These parts become inflamed leading to a discharge of blood in faeces or urine. Damage and inflammation are caused by the escape of eggs from the infected organ to the outside world.
It is caused by schistosomes or blood flukes.
In Tanzania there are two types of schistosomes:
-Spleen becomes very large.
-Irritation in rectum and urinary bladder.
Transmission and life cycle.
Bilharzia worms have two hosts.
Control and prevention.
-Destroy breeding places of snails.
-Keep ducks in water bodies to eat snails.
-Educate people on the importance of using toilets.
The drug niridazole kills one species of Schistosoma but may produce side effects.
Praziquantel seems to be effective against all species and has a few side effects.
Malaria is one of the major killers in the tropics.
Cause:It is caused by a protozoa called plasmodium.
There are four species of the plasmodium that affect humans:
Plasmodium lives in the blood stream of humans but unlike the trypanosomes, maralial parasites enter RBC and feed on their cytoplasm.
-Chills and high fever.
-Nausea and vomiting.
-Loss of appetite.
-General body weakness.
-Headache and joint pains.
Fever occurs every 48 to 72 hours according to which species has been injected.
-Malaria parasites destroy RBC, causing anemia.
-Fatality is possible in several attacks.
-Draining away unwanted ponds, pools and swamps.
-Where draining is difficult, kerosene and insecticides should be used.
-Vegetation should be trimmed.
-Sleep under mosquito nets use insecticides.
-Take preventive medicines regularly.
-Screen windows with mosquito proof were mesh.
Some forms can be treated with drugs such as Quinine, chloroquine or proguanil. New drugs such as Fansidar and Metakelfin have been established to kill malarial parasites.
STI’s are sexually transmitted diseases. They are caused by disease causing organisms. Virus, bacteria and fungi can cause them. STI’s causes STD’s such as gonnorhea, Syphilis, genital herpes and Chlamydia. These are also endemic diseases.
Secondary effects of most STD’s.
-Premature births, still births and abortions.
-Blindness of the foetus.
-Sepsis causing death.
-Infertility and sterility.
Control and prevention.
-By not having sexual intercourse.
-By not sharing clothes.
-By maintaining cleanliness in toilet.
Groups of people likely to be infected by STD’s.
-Prostitutes who have intercourse for money.
-Other people who have had intercourse with other people.
-Casual acquaintances whose sexual activities are unknown.
Mostly young people are infected by STD’s.
It is a contagious infection of the mucus membrane of the genital tract.
It is caused by a bacterium called Neisseria gonnorrhoeae or more often known as gonococcus. It affects the urethra in males and vaginal tract in females.
-A discharge of mucus and pus from urethra or vagina.
-Men experience pain and itching in urethra during urination.
-Women feel pain in lower abdomen.
-If not well treated, both sexes may become sterile.
-If it finds a way into the vas deferens, the testes swell and pain.
It is usually through sexual intercourse, and sometimes by birth.
Control and treatment:
It can be avoided by not having sexual intercourse.
It can be treated by kanamycin, streptomycin and penicillin.
It is caused by an organism called Treponema pallidum. It is more dangerous than gonnorhoea.
-They may affect any part of the body.
-A hard swelling and ulcer may develop on sexual organs.
-If bacteria has invaded the body, it may cause skin rash and swollen lymph nodes.
-If not treated early, the spirochaetes form pockets of permanent infection in the body, causing inflammation, persistent ulcers and obstruction of the arteries.
-If bacteria invades heart or brain, they cause death.
-In pregnant women, Treponema bacteria can get across the placenta and infect the foetus. The infected foetus becomes mentally retarded and dies at an early age.
It can be transmitted mainly through sexual intercourse.
It can also be transmitted from mother to child through placenta.
Prevention and treatment:
-Avoiding irresponsible sexual behaviour.
-Antibiotics such as benzathine, penicillin and tetracycline are used to treat syphilis.
A virus called Herpes simplex causes it.
-Symptoms usually show up 21 days after exposure.
-Small painful blisters appear on sex organs.
-Blisters like drops of water on the skin burst and form open sores.
-The open sores dry up and become scabs.
-They can also result in the mouth as result of oral sex.
-Fever, nausea and genital pain often occur during the first episode.
It is spread through sexual intercourse.
It can be treated by Acyclovir.
It is the most widespread STD today. It is very common in teenagers and young adults. It is caused by a bacterium called Clamydia trachomatis.
-White spots on mouth.
-White and grey vaginal discharge.
-Lower abdominal pain.
-Bleeding between menstrual periods.
-Low grade fever occurs.
-Burning when urinating.
-Itching around penis.
-Pain and swelling in testicles.
-Low grade fever occurs.
-It can be transmitted through sexual intercourse.
-It can be avoided by not engaging in irresponsible sexual behaviour.
Antibiotics such as azithromycin, doxycycline and ofloxacin can treat it.
Kaposis sarcoma is a cancer of the skin and blood vessels, and of pneumonia caused by Pneumocytis carinii protozoa. It came to be known as Acquired Immune deficiency syndrome or AIDS.
What is HIV?
It is Human Immune deficiency virus. It is mainly found in body fluids such as semen, blood and vaginal secretions. Low amount have also been found in sweat, saliva and tears.
Signs and symptoms:
-Loss of weight.
-Fever and diarrhoea for more than one month.
-Severe cough for more than one month.
-Abnormal inflammation of lymph nodes.
-Abnormal mental condition signs.
Effects of HIV/AIDS.
-Infections e.g. TB, Skin cancer, pneumonia and diarrhoea.
Prevention and control:
-Through health and sex education.
-We can protect ourselves by avoiding unsafe sexual intercourse.
By following ABC rule:
-Avoid blood transfusion.
-Pregnant women with HIV/AIDS should go to clinic.
Care and support for people living with HIV/AIDS – (PLWHA.)
-Keep wounds covered.
-Do not share sharp things.
-Keep patients bed sheet clean.
-Keep patients clean by disposing his faeces, urine etc.
-Give patient extra fluid to drink.
-Don’t let the person smoke or use alcohol.
-Offer patient plenty of rest.
-Offer patient words of wisdom, hope and success.
-Never discriminate or stigmatize the patient.
GUIDANCE AND COUNSELING FOR PLWHA.
Guidance means the process of helping an individual to gain self understanding and self direction.
Counseling is the process of helping a person to accept and use information or advice so he can solve his problem.
Aims of HIV/AIDS counseling.
-To reduce rate of HIV/AIDS transmission.
-To help those people already infected with the virus.
Stages of guidance and counseling.
It is a counseling that is given to the client before the blood is taken for testing to ascertain HIV/AIDS infection.
-Helping the client know what HIV/AIDS is.
-Means of transmission.
-Meaning of HIV test.
-Meaning of a positive or negative test result.
-Need for a confirmatory test.
-Need to practice safe sex.
-Need for informing sexual partners.
-Spiritual and material support.
-Possible treatment program.
-Safe sexual practices.
-How to avoid infections.
Is a counseling given to a victim after confirming him to have positive results of HIV.
It is the system of sorting out and placing organisms into different groups on the basis of their similarities and differences.
Types of classification:
There are two types of classification:
In this system only one or a small number of features are considered e.g. birds and bats all have the ability to fly. So by using this system, one can place the birds and bats in one group. Just by considering one feature that is the ability to fly. But in reality, birds and bats are classified into different groups.
Birds -> Aves.
Bats -> Mammals.
In this system, organisms are placed in their natural groups by:
Homology- Similarity of origin.
Analogy- Similarity of use.
Example of Homology:
The arms of a man, forelimbs of whales and wings of birds or bats are homologous because they have same order and pattern of bones. So these show that they have the same origin.
Example of Analogy:
The wings of birds and grasshoppers are analogous, because birds have internal skeleton (endoskeleton) and grasshoppers have external skeleton (exoskeleton). So these wings perform the same function but have different origins.
Importance of classification:
Advantages of Artificial classification.
Disadvantages of Artificial classification.
Advantages of Natural classification.
-Unrelated organisms can’t be placed in the same group.
-Closely related organisms with common characteristics features are placed in the same related group.
-Because it uses same system of naming organisms.
Disadvantages of Natural classification.
It is not based on easy and simple characteristics but on evolutionary relationships.
Is a scientific system of naming living organisms whereby each organism is assigned two names. The first name being the Genus and the second name is the species.
Note- Bi means two, Nomino means name.
So Binominal means two names.
Rules of binominal nomenclature:
Eg: Homo sapiens (Romanic)
Homo sapiens (Italic)
Examples of scientific names:
Man – Romanic:Homo sapiens.
Elephant – Romanic:Loxodorita africane.
Maize – Romanic:Zea mays.
Dog – Romanic:Canis familiasis.
Lion – Romanic:Panthea leo.
Ranks of classification (Toxonomic.)
Ranks are the groups into which organisms are placed as the matter of convenience based on easily observable features, that are shared in common for group identification.
These are seven major ranks of classification, they are:
Genus:Is a group of organisms with a large number of similarities but unable to interbreed successfully.
Species:Is a group of organisms which are capable of interbreeding together and produce fertile offsprings.
THE MAJOR KINGDOMS.
There are five major kingdoms of living things. These major kingdoms exclude a virus. Because the virus is between living and non-living things. The major kingdoms are:
Is a chemical between living and non-living things.
Characteristics of a virus:
Economic importance of virus.
Kingdom Monera (Bacteria)
Forms of bacteria.
Coccus:It causes sore throat.
Streptococcus:Causes sore throat.
Bacterium:Bacillus anthrax:Causes anthrax.
Economic importance of bacteria:
1. Production of antibiotics.
Members of these kingdom resembles the ancestors of plants, animals and fungi. These are the algae, protozoa etc. In protozoa we have amoeba and paramecium etc. other members of this kingdom are euglena and trypanosome. Algae contains red, brown and green algae.
General characteristics of Kingdom Protoctista:
Economic importance of Kingdom protoctista.
There are of 4 species:
The function of the Golgi complex (apparatus) is to collect and pack all molecules synthesized within the cell.