Friday, 20 February 2015



CONSERVATION AND POLLUTION (3 UNITS)
This course is centred on two sections viz
(A). Natural Resources of the world with emphasis on Nigeria, the values, utilization, destruction and principles of management.
(B). Concept of pollution, pollutants, and their biological effects, environmental Impact Assessment, control and future prospects.

CONSERVATION OF NATURAL RESOURCES
This aspect deals with section A above ie Natural Resources of the world with emphasis on Nigeria, the values, utilization, destruction and principles of management.

NATURAL RESOURCES
What is a resource?
A resource is anything that is valuable to man. It could be a living thing or non-living thing. It could be gaseous, liquid or solid.

Occurrence of Natural Resources
Natural resources are not man-made. They occur in nature within environments that exist relatively undisturbed by man. A natural resource is can be viewed jn terms of biodiversity and extant geodiversity in various ecosystems. Biodiversity refers to the totality of various forms of living organisms in a given locality. It refers to various genotypic and phenotypically expressed traits in animals, plants, bacteria, viruses, and fungi in a locality. The foregoing shows that biodiversity is a measure of the variety of organisms in different ecosystems. By extension this refers to genetic variation, ecosystem variation, or species variation (number of species) within an area, a biome or planet.
Geodiversity is the variety of earth materials, forms and processes that constitute the planet Earth and shape it. Relevant materials include minerals, rocks, sediments, fossil, soils, and water. Forms may comprise folds, forms, faults and landforms as well as other expressions of morphology or relations between units of earth material.
An ecosystem is a community of living organisms including plants, animals and microbes in conjunction with the non-living components of their environment including the air, water and mineral soil, interacting with one another as a system. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Ecosystems can be of any size but usually encompass specific, limited spaces.
Natural resources are derived from the environment. Some of them are essential for our survival while most are used for satisfying our needs. Natural resources may be further classified in different ways.
Natural resources are materials and components (something that can be used) that can be found within the environment. Every man-made product is composed of natural resources (at its fundamental level). A natural resource may exist as a separate entity such as fresh water, and air, as well as a living organism such as a fish, or it may exist in an alternate form which must be processed to obtain the resource such as metal ores, oil, and most forms of energy.
Some natural resources such as sunlight and air can be found everywhere, and are known as ubiquitous resources. However, most resources only occur in small sporadic areas, and are referred to as localized resources. There are very few resources that are considered inexhaustible; these are solar radiation, geothermal energy, and air. The vast majority of resources are exhaustible, which means they have a finite quantity, and can be depleted if not well managed.



Classification of Natural Resources
Natural Resources can be classified using the following criteria:
1.      Origin
2.      Stage of Development
3.      Renewability
On the basis of origin, natural resources can be divided into:
A.      Biotic – Biotic resources are obtained from the biosphere (ie living and organic materials), such as forests and animals, and the materials or products that can be obtained from them. Please note that fossil fuels such as coal and crude oil belong to this category  since they are formed from decayed organic matter.
  1. Abiotic – Abiotic resources are those from non-living, non-organic material. Examples include land, fresh water, air and heavy metals including ores such as gold, iron, copper, silver etc.
On the basis of their stage of development, natural resources can be divided as follows:
A.      Potential resources – Potential resources are those that exist in a region and may be used in the future. For example crude oil (petroleum) occurs with sedimentary rocks in various regions, but until the time comes when it is actually drilled out and put into use, it remains a potential resource.
  1. Actual resources – Actual resources are those that have been surveyed, their quantity and quality determined, and are being used in presently. The development of an actual resource, such as wood depends upon the technology available and the cost involved.
  2. Reserve resources – The part of an actual resource which can be developed profitably in the future is known as a reserve resource.
  3. Stock resources – Stock resources are those that have been surveyed but cannot be used by organisms due to lack of technology.
On the basis of Renewability natural resources can be grouped as either renewable or non-renewable:
A.      Renewable resources: Renewable resources are those that can be replenished through natural processes. Some of these resources, like sunlight, air, wind, etc., are available continually and their quantity is not noticeably affected by human consumption or exploitation. Viewed from a human use perspective resources are classified as renewable if  the rate of replenishment or recovery exceeds that of consumption.
Non-renewable resources:  These are resources that either form slowly or do not naturally form in the environment. Minerals are the most common resource included in this category. From the human use perspective, these resources are non-renewable when their rate of consumption exceeds the rate of replenishment or recovery; a good example of this are fossil fuels, which are in this category because their rate of formation is extremely slow, running to millions of years hence, they are considered non-renewable. 


To be updated soon.

Tuesday, 3 February 2015

BASIC PRINCIPLES OF BIOLOGY



THE HIERARCHY OF LIFE

Life has a hierarchy!
Every living entity does not occur as a whole without its pieces or component parts or portions (see Figure 1). These portions aggregate or complicate to become higher levels of  biological organization also referred to as the hierarchy of life. The hierarchy of life is the orderly arrangement of complex biological structures and systems that define life. Understanding this basis of entities helps in understanding and solving problems and predicaments as they arise in living systems. For example, when studying an elephant with a disease, you can break the animal down into different parts and study the disease at these different levels.There is no hard and fast rule as the number of this organization that is existing, but asically, there are 11 levels of biological organization. Each of these describes a hierarchy of organisation.


Figure 1: Levels of Biological Organization
  Biosphere -This includes all ecosystems. An ecosystem is a short form of ecological system.
Ecosystem
- consists of all organisms living in a particular area, as well as the nonliving, physical components of the environment

Community
- consists of various populations of organisms living together in a given area

Population
- a group of organisms of the same species in any given area. Organisms are of the same species if they are actually or potentially interbreeding and producing viable offspring. Two horses are therefore of the same species but a horse and a donkey are not the same species even though they look alike. A donkey crossed with a horse results in a mule. But a mule is not a viable offspring as it cannot reproduce itself. Similarly a lion is not the same species as a tiger. But a cross between a Lion and a tiger results in a Liger which also is not viable.

Organism
- within a population there are organisms, just one of those organisms is called an organism. For example, within a population lions, there is a lion.

Organ system
- consists of different organs that work together for a specific function.

Organ
- consists of different tissues that function together to do a certain job

Tissue
- consists of similar cells that work together

Cell
- the smallest unit of life that is able to carry out all the functions of living things

Molecule
- consists of different atoms. For example, DNA, within DNA there are oxygen atoms and different proteins.

Atom
- the smallest unit of matter that has the chemical properties of a particular element.

Take note that thes levels are all related to one another. For example, a biosphere contains all of the mentioned levels above. So, each level contains the level before it and they all fit into each other just as it has been earlier indicated. Knowing the difference between the levels is helpful because it makes it easier when comparing different things.


The biological organization of life is a fundamental premise for numerous areas of scientific research, particularly in the medical sciences. Without this necessary degree of organization, it would be much more difficult—and likely impossible—to apply the study of the effects of various physical and chemical phenomena to diseases and body function.

Consider the following examples:
  1. The fields such as cognitive and behavioral neuroscience could not exist if the brain was not composed of specific types of cells.
  2. The basic concepts of pharcology could not exist if it was not known that a change at the cellular level can affect an entire organism.
  3. The direct effect of the notorious chenical named DichloroDiphenyle Trichloroethane but popularly known as DDT occurs at the subcellular level, but it affects higher levels up to and including multiple ecosystems.
  4. Also a change in one atom could change the entire biosphere.