• DRUG ABUSE III
• FAMILY TRAITS
• ENVIROMENTAL HAZARD (SOIL EROSION)
• ENVIRONMENTAL HAZARD (BUSH BURNING)
• FLOODING
• ENVIRONMENTAL HAZARD (DEFORESTATION)
• ENVIRONMENTAL HAZARD (DESERTIFICATION)
• ENVIRONMENTAL HAZARD (DEPLETION OF THE OZONE LAYER)

Drug Abuse III

Basic Science JSS 3 First Term

Week  1 & 2

Topic: Drug Abuse III

Introduction

Drug abuse means taking drugs not according to doctor’s prescription. It could be by either taking overdose or under dose. Some common hard drugs that are easily abused or misused are heroin, cocaine, valium, madras and Indian hemp. People who abuse drugs easily are athletes, prostitutes and criminals.

 Modes of Drug Abuse

1. Self Injection – This involves injecting drugs directly into the blood stream through capillaries, arteries or veins. Injecting drugs is the fastest method for experiencing the high from drug use because it puts the drug directly into the bloodstream. Drugs can be injected into the soft tissue, into the muscle or directly into the vein. Individuals who inject drugs will experience the high within 3 to 5 seconds (immediately).
2. Sniffing/Inhaling/Snorting – Some individuals snort/sniff drugs such as ecstasy, cocaine, heroin and amphetamines. Drugs enter into the bloodstream through the nasal mucus membranes and through the stomach. Individuals snorting/sniffing drugs will experience the drug sensation within about 15 minutes after snorting their drugs.
3. Absorption through the skin – Drugs used in this form are mild body creams. Some are used to maintain the skin while some are used to treat skin diseases.
4. Oral/Swallowing – Ingesting or swallowing drugs is the most common method of drug use. The individual takes the drugs by mouth. The drugs pass to the stomach and then into the bloodstream
5. Rectal – Drugs are delivered into the bloodstream through the rectum’s mucus membrane. This is not a common method of drug abuse, drugs that have been taken using this method are cocaine, speed and ecstasy.
6. Smoking – This method gets the drugs into the body’s system a bit faster than swallowing the drugs because the smoke goes into the lungs where it quickly moves into the bloodstream. The most common drugs that are smoked are marijuana, heroin, crack and opium.

Effects of Drug Abuse

Drug abuse has so many negative effects, which are:

1. Drug abuse hurts the people who take drugs and the people around them, including families, kids, and babies who aren’t yet born.
2. It can lead to damaged nostrils and lungs.
3. It can lead to skin rashes.
4. It can lead to injection abscesses.
5. It can lead to poor academic achievement.
6. It can lead to uncontrollable sexual urge
7. Drug abuse sometimes lead to death
8. They are usually lazy and have wrong attitudes to work
9. Excessive smoking damages the lungs and ruins the health of smokers for life.
10. Regular take of drugs make a person dependent on the drugs and feel cannot do anything else without the drugs.
11. Excessive drug intake can make a person go insane or develop mental problem
12. It can lead to accident
13. It can lead to stomach upset.

Prevention of Drug Abuse

1. Inculcation of Coping Skills: this should involve the determination to stop the abuse of drugs and the need to get rehabilitated.
2. Positive Social Interactions: These should involve avoiding peer partners that are drug abusers as well as not associating with those friends who smoke cigarettes and drink excessively.
3. Healthy Lifestyle:

• Youth should avoid self-medication when they are sick.
• They should avoid smoking and excessive drinking of alcohol.
• They should eat good food (balanced diet) always.
• People should control their desires and appetite.
• There should be open campaign against drug abuse.
• There should be public teaching (enlightenment) through the use of posters and public address system against drug abuse.

Drug Control Agencies

In Nigeria, the drug control agencies are:

National Agency for Food Drug Administration and Control (NAFDAC):

1. The agency ensures that adulterated food is not sold to the public.
2. Ensures that proper quality control of manufacture food is maintained in the industries.
3. Ensures that expired food substances are not sold to Nigerians.
4. Ensures prosecution of offenders to the rules and regulations guiding the manufacturing and sale of processed food materials.
5. Creates enlightenment programme for food manufacturers and vendors.

National Drug Law Enforcement Agency (NDLEA):

1. The agency monitors the movement of hard drugs in and out of the country.
2. Ensure that drug barons are severely punished according to the laws of the country.
3. Organizes orientation and rehabilitation programmes for hard drug users who might wish to give up the habit.

Assessment

• Briefly explain five modes of drug abuse
• List seven negative effects of drug abuse
• Mention five ways to prevent drug abuse

FAMILY TRAITS

Basic Science JSS 3 First Term

Week 3

Topic: Family Traits (Genetics)

Meaning of Genetics, Heredity and Variation

Genetics: is defined as the study of heredity and variation in living things.The study of heredity, or how the characteristics of living things are transmitted from one generation to the next. Every living thing contains the genetic material that makes up DNA molecules. This material is passed on when organisms reproduce. The basic unit of heredity is the gene.

Genetics is the process of a parent passing certain genes to their children. A person’s appearance — height, hair color, skin color, and eye color — is determined by genes. Other characteristics affected by heredity are:

• Likelihood of getting certain diseases
• Mental abilities
• Natural talents

An abnormal trait (anomaly) that is passed down through families (inherited) may:

• Have no effect on your health or well-being — for example, the trait might just cause a white patch of hair or an earlobe that is longer than normal
• Have only a minor effect — for example, color blindness
• Have a major effect on your quality or length of life

Heredity (Inheritance): is defined as the transmission of characters from parents to offspring via genes. It is responsible for the similarity and small differences between parents and offspring. Heredity is the sum of the qualities and potentialities genetically derived from one’s ancestors. It is also defined as the transmission of traits from ancestor to descendant through the molecular mechanism lying primarily in the DNA or RNA of the genes. Heredity is the passing of phenotypic traits from parents to their offspring, either through asexual reproduction or sexual reproduction. This is the process by which an offspring cell or organism acquires or becomes predisposed to the characteristics of its parent cell or organism.

Variation: is defined as the differences which exist between parents and offspring as well as among the offspring.Variation, is any difference between cells, individual organisms, or groups of organisms of any species caused either by genetic differences (genotypic variation) or by the effect of environmental factors on the expression of the genetic potentials (phenotypic variation).

Therefore, family traits are those inherited characters, which show variations among members of a family. The features that you use to recognize the parents of each child are called Family Traits. These traits are transmittable characters which are passed from parents to offspring from one generation to another. Some characters that are genetically transferred from parents to offspring include

1. shape of face, forehead, eyes, nose, mouth and ears 
2. colour of skin, hair and eyes
3. height of the body
4. method of walking
5. quantity of hair, eyebrow and eyelashes and some genetic disease conditions such as albinism, sickle cells anaemia, colour blindness, etc.

Meaning of Dominant and Recessive Traits

Dominant Traits: These are trait that keeps appearing in each successive generation.

Recessive Traits: These are trait present in a living organism, yet they do not appear physically because of the dominant trait in the offspring, but may suddenly appear in successive generation.

For example, a dominant tall man (AA) who married a recessive short woman (aa) may not produce any short child or children. But the children having the recessive traits or genes may produce short child or children by the second generation.

Comparison between Dominant and Recessive Traits

Dominant Traits	Recessive Traits
Traits are manifested outwardly	Traits are not manifested outwardly
Traits are controlled by dominant genes	Traits are controlled by the recessive genes

Importance of Family Traits

a) Intelligence: Intelligent parents usually give birth to intelligent children. This trait (character) seems to be continuous in most family generations.

b) Diseases: The study of family traits has helped in the understanding of some genetic diseases like albinism, sickle cell anaemia, colour blindness, etc. Prospective spouses are counseled to check their genetic make-up before entering into marriage to avoid transmitting genetic diseases.

c)  Resemblance: Family trait also helps to identify a member of a particular family.

d) Family Genealogy: One can easily trace a person’s ancestor (lineage) and predict his present and future characteristics through the family traits.

Assessment

• Briefly describe the following terms; Genetics, Heredity, and variation
• Differentiate between dominant and recessive traits

ENVIROMENTAL HAZARD (SOIL EROSION)

Basic Science JSS 3 First Term

Week 4

Topic: Environmental Hazard (Soil Erosion)

Introduction

Soil is the top layer of the earth crust. Human activities, such as road construction, farming, building of houses, etc., take place on the soil. The top layer of the earth could be washed away as a result of water, wind, volcanic action and rainfall.

Soil erosion is the gradual wearing away of the surface of the earth (topsoil) through the action of wind, rain, etc.

Causes of Soil Erosion

Wind, bush burning and water are the major causes of erosion.

Bush burning: This destroys humus and plant nutrients, which makes the soil loose and the sand can then be washed away by wind or water. Some people burn bushes during game hunting while others burn bushes in order to make new grass grow up for feeding cattle. When the bush is burnt, the surface of the ground is exposed making it possible for rain and wind to remove the top soil, thereby causing erosion.

Farming: Farmers cut the vegetation before tiling the ground on which they intend to plant their crops. Both removal of vegetation and tiling of the ground aid erosion.

Road Construction: The construction of roads involves clearing bushes and the use of heavy equipment such as graders, to work on the ground surfaces. The soil is disturbed by heavy equipment, resulting in the tearing of the soil and thus erosion.

Growth of Towns: As towns grow and houses have to be built, bushes are cut and cleared. This exposes the soil to erosion, Also roofs of houses collect rain water and create heavy downpour onto the soil.

Wind Erosion: Bush clearing exposes the land. Weathering causes a breakdown of the earth’s surface. As the wind blows over open surfaces of the earth, particles of the sand or rock are blown away. Wind erosion is common in the desert environment. The wind blows dry sand particles away from the site.

Water Erosion: This is common in dry sandy areas where the water flow washes away large areas of the land. When rain falls, the rain water moves in small temporary trenches. These trenches are often referred to as rill and leads to rill erosion.

Methods of Controlling Soil Erosion

Wind, chemical weathering and human activities as a result of bush clearing for farming are major causes of erosion.

Erosion can be controlled or prevented by:

1. Preventing bush burning
2. Planting trees or grass – This is done to cover the soil. Planting of trees can help control soil erosion. The trees or grass break the force of the raindrops on the soil. This prevents the wearing away of the top soil by wind or water. Trees that can do this most are bamboo and cashew trees, especially in sandy soil since they have extensive root systems.
3. Trees which help to reduce wind erosion are called wind breaks.
4. Making ridges across the land to prevent the washing off of the soil by rain – If ridges are made on hillside farm land, the flood that runs down the slope will be blocked and erosion reduced.
5. Terracing – Terracing means making of a series of ridges or steps that resemble a staircase on a slope. This makes water-flow down the slope to slow down at every step thus breaking the speed of flow of water.
6. Strip cropping – Crops that provide vegetation cover for soils and those that do not can be planted in alternate strips across a slope so that the effect of the rain or flood in exposed parts is checked by vegetation in covered parts.
7. Mulching – Covering beds, ridges or mound in a farm with dry grass is called Mulching. Mulching helps to reduce the loss of soil moisture, controlling the growth of weeds and keeping the soil cool. Mulching is the control method employed by using dry grass to cover ridges and mounds in the farm. 
8. Cross bars are ridges made in a farm to stop the rushing of floodwater from one part of the farm to another. This reduces the speed of flow of floodwater as a bump reduces the speed of traffic on a road. In this way, crossbars reduce erosion.

Assessment

• Briefly explain the causes of soil erosion
• Mention five methods of controlling soil erosion

ENVIRONMENTAL HAZARD (Bush Burning)

Basic Science JSS 3 First Term

Week 5

Topic: Bush Burning

Introduction

Bush burning is the act of setting forests, weeds and grasses on fire. Farmers clear farmland in preparation for the planting season. The weeds and grasses cleared are often burnt. Forest is a large area of land that is thickly covered with trees. The trees naturally grow on their own or are cultivated by man for different purposes. Mammals, birds and reptiles make the forest their habitat.

Practices that Influence Bush Burning

Some of the practices that influence bush burning include:

1. Bush Clearing: This is the act of removing weeds, grasses and trees so as to plant crops on the farmland.
2. Practice of Crop Rotation: In crop rotation, plants are grown in a particular area and rotated through a period of time (3 or 4 or 5 or 6 years). During this period, the crops grown on a particular area are cleared and burnt.
3. The practice of planting one type of crop on a plot of land at a time. Harvesting same before planting another crop on the same plot of land. After harvesting, the plot of land is cleared.
4. Construction of roads and felling of trees.
5. Building of houses, industries and settlements.
6. Hunting.

Effects of Bush Burning including Economic Consequences

Bush burning has adverse effects on the farmland. It is a practice by farmers to clear an area of bush or forests for planting their crops.

1. It destroys plants community.
2. Humus on the surface of the soil is burnt – loss of soil fertility.
3. Animals that live on the plant community are either killed or forced to move to other suitable surrounding area for their existence.
4. The cleared area is exposed to erosion.
5. Bush burning can make the soil to become powdery and dry over the years. Such a farmland will no longer support plant growth, resulting in a barren land (desert condition).
6. Useful crops, such as oil palm, orange trees, etc may be burnt.
7. Bacteria, earthworm and fungi which bring about decay are also burnt. This causes loss of soil fertility.
8. Low crop yield results from bush burning.

Regulation against Bush Burning

1. There is need for public enlightenment on bush burning.
2. Regulations should be made to prohibit bush burning.

Assessment

• Mention five practices that influence bush burning
• List four effects of bush burning on the economy

FLOODING

Basic Science JSS 3 First Term

Week 6

Topic: Flooding

Introduction

Flood occurs when a large amount of water covers an area that is usually dry. Flooding may occur after a heavy downpour of rainfall. When a river overflows its banks, flooding may also occur.

Drainage Patterns

The drainage pattern in a city or town may be blocked by refuse. When rain falls, water cannot flow freely in a blocked drainage. Hence, the rain water overflows the drain, spreading over adjourning area. Two main types of drainage patterns are observable: the pattern used in rural areas, i.e. villages, and the pattern used in urban and well-planned areas, i.e. towns and cities.

In the rural areas, drainage is not designed and constructed by competent engineers. In some  cases, the villagers dig sloppy and shallow gutters by the sides of the major roads in the village, so the rainwater and waste water poured into them can flow along the roads. 

In the urban areas, on the other hand, surface drainage paths are designed and constructed by competent engineers. The floor of the gutter is made of concrete and is designed to have a slope that allows water to flow away easily.

Causes of Flooding

1. Heavy downpour of rainfall
2. Blocked drainage
3. Indiscriminate dumping of refuse into rivers, streams etc.
4. Release of excess water in dams
5. No gutter s on either side of roads

Flooding can be controlled by the following

1. Removing or cleaning materials from the drainage system.
2. Building of high walls to keep rivers from over flowing their banks.
3. Widening of straightening of rivers.
4. Diversion of streams so that they do not overflow into river.
5. Building of dams to hold back water in river.

Effects of Flooding on Community and Farmland

a) The soil becomes waterlogged and often times muddy

b)  People cannot travel easily on roads

c)  Food crops are damaged

d)  Building s may also become submerged in flooded area

e)  Where flooding occurs annually, people are moved away from the area.

Assessment

• List five causes of flooding
• Mention ways to control flooding effectively

ENVIRONMENTAL HAZARD (DEFORESTATION)

Basic Science JSS 3 First Term

Week 7 & 8 

Topic: Deforestation

Introduction

Deforestation is the act of cutting down of trees in an area.

Forests are of great importance to us and our environment. But the rate at which the trees and forests are cleared is so alarming and could leads to deforestation. Trees are being cut down indiscriminately for timber, firewood, establishment of industries etc. which could pose serious environmental and climatic problems as wildlife is widely affected,  leading to destruction of the animals habitat, wild life extinction and soil erosion.

Reasons for Deforestation

1. The reasons for deforestation include:
2. Production of timber for wood works e.g. furniture.
3. Production of firewood and charcoal for domestic and industrial purposes.
4. Urbanization of towns.
5. Establishment of industries, markets, churches, houses, mosques, etc.
6. Construction of roads and bridges, etc.

Effects of Deforestation on the Environment

The effects of deforestation include:

1. Destruction of windbreaks which gives way for adverse wind attack.
2. Soil erosion which causes destruction to farmland and buildings.
3. Global warming caused by large concentration of CO2
4. Intense evaporation of soil water and soil nutrients due to exposure of the soil.
5. Danger to wildlife and possible extinction of some species of plants and animals.
6. Shortage of food due to drought.
7. Destruction of arboreal habitat.
8. Leads to loss of forest resources.

Regulations of Deforestation

Government has enacted laws and strict regulations to control deforestation. In order to protect the forest from excessive exploitation, government has introduced the following regulations on deforestation.

1. Government has set out large expanse of land and forest as reserved areas.
2. Government has made laws that will guide and preserve forests from human destruction.
3. When trees are felled they should be replanted. This process of replanting trees is known as reafforestation.
4. Anybody who fails to keep any these regulations should be punished or made to pay a heavy fine to deter others from destroying forests.
5. Foresting should be made compulsory in our educational curriculum.

Assessment

• Mention four reasons for deforestation
• List five effects of deforestation or the environment
• Mention four regulations by the government on deforestation

 ENVIRONMENTAL HAZARD (DESERTIFICATION)

Basic Science JSS 3 First Term

Week 9

Topic: Desertification

Introduction

Nowadays, there are high increases in environmental disasters caused by man’s activities. Indiscriminate cutting down of trees, mining, intensive continuous farming, road construction, overgrazing and bush burning are some of man’s activities that contribute to environmental degradation such as exposing the soil to intense and ultraviolent radiation of the sun, leading to excessive evaporation, and loosening of the soil texture, making the soil easily eroded by wind and water. Investigations have shown present and future problems that will result if adequate measures are not taken to curb these activities of man. One of the harmful activities of man is desert encroachment or desertification.

Definition

Desertification is the process by which fertile land becomes desert, typically as a result of drought, deforestation, or inappropriate agriculture. It is also described as the encroachment of desert into habitable land. Desert encroachment is simply the gradual movement of a desert towards an area causing such an area to become a desert. In a nutshell, desertification is a situation in which an entire area becomes a desert in a short span of time

Geographical Area in Nigeria

There are two broad geographical zones in Nigeria. These are the tropical forest zone and the savanna. These geographical zones are further divided into six areas or belts. These include:

1. The mangrove belts around the delta region,
2. The tropical rain forest zone,
3. Derived savanna,
4. Guinea savanna,
5. Sudan savanna,
6. Sahel savanna.

The zones closer to the dry lands (deserts) are more prone to desertification. Therefore, people living around these zones should adopt appropriate environmental measures to control this adverse effect.

Causes of Desertification

These include:

1. Overgrazing
2. Removal of crop residues for feed/construction use
3. Deforestation for fuel wood and construction materials
4. Inappropriate irrigation practices that lead to salinity
5. Drought
6. Climatic shifts
7. Bush burning

Controls Measures on Desertification

Desertification can be controlled by:

1. Avoiding indiscriminate felling of trees.
2. Adopting rotational grazing.
3. Encouraging bush fallowing and shifting cultivation methods.
4. Establishing wind breaks.

Assessment

• List five causes of deforestation and four control measures on desertification

ENVIRONMENTAL HAZARD (DEPLETION OF THE OZONE LAYER)

Basic Science JSS 3 First Term

Week 10

Topic: Depletion of Ozone layer and Its Effects

Introduction

The ozone layer is located in the stratosphere of the atmosphere. The atmosphere is the region of air above the earth surface. There are many gases in the atmosphere. They include carbon (IV) oxide, carbon (II) oxide, ozone and methane. They combine with the chlorofluorocarbons to cause the greenhouse effect. Another layer of the atmosphere is lithosphere. Some water vapour, oxygen and aerosols are found in the stratosphere also.

Importance of the Ozone Layer

The ozone layer contains other gases and materials apart from ozone. Therefore, this layer is important for the following reasons:

1. It brings a cooling effect to the atmosphere and the earth surface.
2. The ozone layer absorbs high energy radiations from the sun. This minimizes the amount of radiation from the sun to the earth surface. These radiations are ultra radiations that cause sunburn to the skin.
3. The presence of the ozone layer prevents the incidence of health hazards like sunburn.

 Effects of Depletion of the Ozone Layer

The depletion of the ozone layer refers to the gradual reduction of the amount of ozone in the layer due to the widening of the opening of the ozone layer. The depletion leads to the following consequences:

1. Global Warming: The atmosphere re-radiates the absorbed energy back to the earth surface, by receiving the re-radiated portion of the energy to the earth, the earth surface become warmer. This leads to global warming.
2. Greenhouse Effect: This is a natural situation that keeps the earth surface warm and suitable for continuous life. This additional warming is called greenhouse effect.
3. Ice Melting and Flooding: Over the years, there is outcry of increased heat intensity. This is due to the widening of the ozone layer that has led to greater radiation from the sun. The heat intensity has caused the polar regions of the world to flood as the ice is now melting. Due to flooding, houses are destroyed and thousands of lives are lost in the tropics.

Control Measures against the Ozone Layer Depletion

The following measures can be used to control the depletion of the ozone layer:

1. Regulation on the use of chlorofluorocarbons (CFCs): The CFCs are used to make the compressors of refrigerators. Used refrigerators should be carefully disposed off.
2. Bush Burning: Bush burning produces huge quantity of carbon (IV) oxide, which causes greenhouse effect. Generally, reducing bush burning is a way of lowering the amount of carbon (IV) oxide in the atmosphere.
3. Regular Servicing of Automobiles: A lot of methane, another compound causing depletion of the ozone layer is produced along smoke from exhaust fumes of cars, especially unserviced automobiles. Owners of vehicles should ensure regular servicing of their vehicles.

The Greenhouse Effect

Carbon dioxide has a green house effect. The atmosphere with high carbon dioxide content has become a blanket round the earth, causing a green house effect. The heat of the sun can pass through the atmosphere into space.  As a result, the temperature of the earth has been increasing progressively. The effects of global warning are many but scientists admit that only some effects are as yet known. These include

1. Increase in atmospheric temperature
2. Progressive melting of polar ice, in the Arctic and Antartic zones as a result of increase in temperature
3. Rising ocean levels
4. Gradual covering of some low dry lands with water from the oceans.
5. Unusual changes in ocean currents
6. Climatic change

Assessment

• State three importance of the ozone layer
• Mention five effects of depletion of the ozone layer