APPLIED ECOLOGY TERM PAPER

1.       Discuss concept of terrestrial and aquatic ecosystems with respect to their features and importance to Nigeria.

2.       Discuss the features of two named biomes found in Nigeria.

3.       Identify the effects of population increase on Natural Resources with respect to west African countries.

4.       Discuss plant and animal resources in (i) Savannah ecosystem in Nigeria (ii) Rainforest Ecosystem of a named west African country. 

POST YOUR RESPONSE AS COMMENTS BELOW.

GENERAL HISTOLOGY NOTES

MEANING AND SCOPE OF HISTOLOGY

Animal and plant bodies are made up of several cells, known generally as the basic unit of life, which aggregate and coordinate together as tissues. The study of these tissues is referred to as histology. The word Histology is derived from two Greek words (i) “Histos” and (ii) “logia”. The Greek word “Histos” means “Tissues” and “Logia” means “Study of”. These two put together means “Study of Tissues”. Thus Histology is described as the study of tissues. Hickman et al (2001) describes a tissue as “an aggregation of cells and cell products of similar structure and embryonic origin performing common functions”. In a similar manner that cells make tissues, so also organs and organ systems are made up of tissues. The scope of histology therefore consists of the following:

i.                     Cytology – the study of cells.

ii.                   Histology – the study of tissues.

iii.                  Organology – the study of organ and organ systems.

iv.                 Gross Anatomy – the study of the whole or component part of animals.

The study of cells (Cytology) has been dealt with extensively in another course (BIO 201 – Cell Biology). The student is advised to review that course for a good grounding for the basis of histology. These lectures may therefore focus more on tissues and their higher organizations including organs and organ systems especially of the mammalian body. This makes it extremely important for the student of histology to also review courses that have dealt with mammalian body especially ZOO 102 (Organization of Mammalian Body) and ZOO 303 (Comparative Vertebrate Anatomy).

TISSUES

The body of animals consists of different types of tissues. These mainly include the following:

(i)                  Epithelial Tissues.

(ii)                Connective Tissues.

(iii)               Muscle Tissues

(iv)              Nervous Tissues

Epithelial Tissues – Structure, Types and Functions

Epithelial tissue cover the surfaces various structures in the body. They form both internal and external coverings. An epithelial tissue that cover surfaces on the interior of the structure is known as endothelium while the one covering external surface of a structure is called epithelium. Each epithelial Tissue is made up of cells that are arranged in closely packed fashion. They may be arranged as one or more layers. Epithelial cells are packed tightly together, with almost no intercellular spaces and only a small amount of intercellular substance. An epithelial tissue, irrespective of its type, is usually separated from the underlying tissue by a thin sheet of connective tissue called basement membrane. The basement membrane provides structural support for the epithelium and also binds it to adjoining structures.

The types of epithelial tissues are identified on the following bases:

i.                     The shape and function of their cells (Squamous, cuboidal, columnar or transitional)

ii.                   The number of layers they have (Simple if only one layer and Stratified if more than one layer).

Simple epithelium

As stated above, simple epithelia can be subdivided according to the shape and function of their cells. The following can therefore be recognized:

1.       Squamous epithelium.

Squamous cells have the appearance of thin, flat plates. The shape of the nucleus usually corresponds to the cell form and help to identify the type of epithelium. Squamous cells, for example, tend to have horizontal flattened, elliptical nuclei because of the thin flattened form of the cell. They form the lining of cavities such as the mouth, blood vessels, heart and lungs and make up the outer layers of the skin.

2.       Simple Cuboidal Epithelium.

As their name implies, cuboidal cells are roughly cuboidal in shape. Each cell has a spherical nucleus in the centre. Cuboidal epithelium is found in glands and in the lining of the kidney tubules as well as in the ducts of the glands. They also constitute the germinal epithelium which produces the egg cells in the female ovary and the sperm cells in the male testes.

3.       Simple Columnar Epithelium

The cells that form columnar epithelia are elongated and column-shaped since they are taller than they are wide. The nuclei are elongated and are usually located near the base of the cells. Columnar epithelium forms the lining of the stomach and intestines. Some columnar cells are specialised for sensory reception such as in the nose, ears and the taste buds of the tongue. Goblet cells (unicellular glands) are found between the columnar epithelial cells of the duodenum. They secrete mucus or slime, a lubricating substance which keeps the surface smooth.

Some Columnar Epithelia may be ciliated, the presence of cilia being a surface specialization.  Ciliated columnar epithelia cells are usually simple. These cilia are capable of rapid, rhythmic, wavelike beatings in a certain direction. This movement of the cilia in a certain direction causes the mucus, which is secreted by the goblet cells, to move (flow or stream) in that direction. Ciliated epithelium is usually found in the air passages like the nose. It is also found in the uterus and Fallopian tubes of females. The movement of the cilia propels the ovum to the uterus.

Some columnar epithelia may be glandular in function. Columnar epithelium with goblet cells is called glandular epithelium. Some parts of the glandular epithelium consist of such a large number of goblet cells that there are only a few normal epithelial cells left. Columnar and cuboidal epithelial cells often become specialised as gland cells which are capable of synthesising and secreting certain substances such as enzymes, hormones, milk, mucus, sweat, wax and saliva. Most glands are multicellular including salivary glands.

Stratified Epithelia

In places where body linings have to withstand wear and tear, the epithelia are composed of several layers of cells and are therefore called stratified epithelium. The top cells are flat and scaly and it may or may not be keratinized. Keratinzed cells have deposit of a tough, resistant protein called keratin. The mammalian skin is an example of dry, keratinised, stratified epithelium. Conversely, the lining of the mouth cavity is an example of an unkeratinisied, stratified epithelium.

Functions of Epithelial Tissues

1.       Protection – Some epithelial cells such as those from the skin protect underlying tissue from mechanical injury, harmful chemicals and invasion by microorganisms such as bacteria. They also protect the skin from excessive loss of water.

2.       Sensation – Some epithelia function in the perception of stimuli by their possessors. Specialised epithelial tissues containing sensory nerve endings are found in the skin, eyes, ears, nose and on the tongue.

3. Secretion – As already mentioned, some epithelia are specialized to secret specific chemical substances such as enzymes, hormones and lubricating fluids. These epithelia are found in glands.
4. Absorption – Some epithelial cells that line the small intestine, for example, absorb nutrients from the digestion of food.
5. Excretion – Epithelia tissues found the kidney and the skin are examples of those that functions in excretion. The epithelial tissues found in the kidney, for instance excrete waste products from the body and reabsorb needed materials from the urine. Also, sweat is also excreted from the body by epithelial cells in the sweat glands.
6. Diffusion - Simple epithelium are functionally ideal for the diffusion of gases for example those found in the walls of capillaries and lungs. Some epithelia are therefore important in the exchange of respiratory gases. This is because of their characteristic thing nature.
7. Cleaning – Some ciliated epithelia assist in removing dust particles and foreign bodies that found their ways into air passages.
8. Reduction of Friction - Smooth, tightly-interlocking, epithelial cells lining the entire circulatory system of mammals and reduce friction between the blood and the walls of the blood vessels.

References

1. Hickman, C. P., Hickman, F. M., Kats, L. B. (2001). Laboratory Studies in Integrated Principles of Zoology. Tenth Edition. Mc Graw Hill Publishers, New York. 440pp.

NON-GOVERNMENTAL ORGANIZATIONS IN BIODIVERSITY CONSERVATION IN NIGERIA

A number of Non-Governmental Organizations (NGOs) are involved in conservation of biodiversity in Nigeria. Briefs of some of these NGOs are presented below.

1.      FIELD SOCIETY (NFS)

This Society was established in 1930 by Mr. A.F.B. (Frank) Bridges, B.E.M. (1895-1994). The mission was to explore the flora, fauna, culture and environment of Nigeria. The NFS is Nigeria's oldest volunteer group responsible for biodiversity conservation. The NGO carries out its mandate by organizing trips, talks and publications through its membership. The trips relate to traditional and contemporary culture, nature, the environment, sports and science. Recent trips have been to Yankari Game Reserve, Kano and Katsina Durbars, Omo Forest, Argungu and Benin Republic. Membership is drawn from the regions of Nigeria and United Kingdom (UK). Although it is a national association, It has branches in Lagos, Ibadan, Abeokuta, Benin City, Abuja, Ile Ife and UK  In a bid to actualize its set mandate, the NFS publishes a periodical journal named “The Nigeria Field. This publication chronicles activities of the NFS and  is an important source of scientifically recorded field observations on West Africa. The journal also covers culture, history and art of the Nigerian environment.

 

2. MURTALA MOHAMMED (FOUNDATION) MEMMORIAL BOTANICAL GARDENS

Murtala Muhammed Memorial Botanical Gardens (3MBG) is located along the Lekki – Epe Expressway. It was established by Mrs. Ajoke Muhammed, a Dental Therapist and widow of Late General Murtala Muhammed who devotes most of her time to environmental sustainability and preservation issues. Through this and other related efforts, she also co-ordinates the Green Belt Movement of Nigeria which is currently involved in tree planting and poverty alleviation programmes in some parts of Lagos State.

3. NIGERIA ENVIRONMENTAL STUDY/ACTION TEAM (NEST)

As a membership organization, Nigeria Environmental Study/Action Team (NEST) has the overall goal of acting in concert with an active nationwide membership to sensitize and empower Nigerians on issues of the environment and sustainable development, through the dissemination of factual information, training on skills acquisition and promotion of sustainable livelihoods.

4. PANDRILLUS FOUNDATION

Pandrillus was founded in the 1980s by Liza Gadsby The name Pandrillus comes from the genus for the species Mandrillus, and the Latin word for “all”, Pan. The mission of Pandrillus covers all drills both in captivity and the wild. The mission was to face the challenge of preventing the extinction of the highly endangered drill monkey Mandrillus leucophaeus. The mission of the foundation has since been expanded to include chimpanzees, and other wildlife that share the drill’s habitat.

Pandrillus employs a multi-faceted approach which combines in situ and ex situ activities, including: habitat protection, captive care and breeding, research, training, small scale development schemes, education and positive advocacy. The foundation works in collaboration with state and national governments, communities, traditional rulers, other international and local NGOs, zoos, advisory groups, and the private sector to achieve meet its mandate.

Pandrillus works in Nigeria and Cameroon as a Nigerian-registered non-profit trust. It is also registered in the USA as non-profit organization

 

5. CERCOPAN - Centre for Education, Research and Conservation of Primates and Nature

The mission of CERCOPAN is to conserve Nigeria’s primates through sustainable rainforest conservation, community partnerships, education, primate rehabilitation and research. Its two education and primate rehabilitation centres are the focal points for the organization. The education arm is located in Calabar (since 1995) and the rehab is in Rhoko near Iko Esai (since 2003). To fulfill its mandate CERCOPAN recovers primates through donations or by rescueing them from captors. In this wise, over 100 primates have been donated or rescued from hunters or pet keepers, their parents having been felled for illegal bush meat consumption. Iko Esai is actively conserving approximately 12,000 hectares of community rainforest, including 400 hectares of core protected land within the Akamkpa Local Government Area (LGA) adjacent to Cross River National Park in Akampa. The foundation has involved communities in managing their forests to protect wildlife and habitat. This has led to a community-wide ban on hunting of all primates in Iko Esai where community members are employed in patrolling habitat areas to protect animals such as monkeys, pangolins and forest elephants from poachers. CERCOPAN is also involved in student projects at the research centre at Rhoko Camp, including international research projects.

6. NIGERIAN CONSERVATION FOUNDATION (NCF)

Nigerian Conservation Foundation (NCF) is a foremost Non Governmental Organisation (NGO) dedicated to nature conservation and sustainable development in Nigeria. IT was established by Chief S. L Edu in 1980 and registered in 1982 as a Charitable Trust under the Land (Perpetual Succession) Act of 1961 which was replaced by the Company and Allied Matters Act of 1990.

The vision of NCF is to have “a Nigeria where people prosper while living in harmony with nature”. Her mission is tp preserve the full range of Nigeria’s biodiversity which includes species, ecosystems and genetic biodiversity;  promote the sustainable use of natural resources for the benefit of present and future generations; and advocate actions that minimise pollution and wasteful utilisation of renewable resources. Consequent upon this mission, NCF is a veritable frontier for the conservation of biodiversity in Nigeria. This NGO focuses on environmental education, biodiversity conservation, policy advocacy, public sensitization on environmental issues, mitigating environmental pollution and poverty reduction.

To drive her mission, NCF embarks on various projects which include

1.      Lekki Conservation Centre

2.      Paricipatory Forest Management System

3.      Edo Biodiversity Action Plan

4.      Finima Nature Park

5.      Osse River Park

6.      Omo-Oluwa-Shasha Forest Reserve.

Among these NCF projects, Lekki conservation Centre stands out.

Lekki Conservation Centre  (LCC)

Lekki Conservation Centre (LCC) is located on Lekki Peninsula Eti Osa Local Government Area of Lagos State, where it occupies a land area of 78 hectares.. The LCC is a conservation initiative meant to protect wildlife found in southwest coastal environment of Nigeria amidst sprawling urban development. Over the years, LCC has served, as an education and resource centre for several groups. .

The project has promoted environmental protection and worked against poaching by surrounding communities as well as serve as a tourist centre for local and international visitors. Continuous environmental education, awareness creation and research activities are carried out in the Reserve.

In terms of operations, LCC was established to serve as a conservation outpost of Nigeria’s southwest coastal mangrove resources and an information centre for environmental education and public awareness. Over the years, visiting students from various academic cadres have been able to learn through their visit to LCC practical steps to conserving our God given natural resources. LCC is also an environmental education resource centre to non-educated and semi literate visitors.

.LCC 78 hectare land area is divided into two sections: LCC Complex and the nature reserve.  The LCC Complex comprises of an attractive multi-purpose Rotunda surrounded by four office blocks. The office blocks contain project staff offices, gift shop, canteen and the drivers’ office. The facilities of the LCC Complex area were expanded in 1998 with the construction of the National Secretariat at the rear of LCC Complex. The nature reserve cuts across several vegetation types namely: secondary forest, swamp forest and Savanna grassland.

The swamp outlook affords tourists, especially nature lovers’ mouth watering opportunity of sitting back to beyond aquatic and terrestrial ecosystem interaction. On the other hand, there is a bird hide that enables bird watchers to view avifauna that are wading through the pool overlooked by the hide or foraging within the vicinity.  There is also a tree house. The tree house is one of the most fascinating features one can ever come across in an ecotourism zone. The tree house, is located on a stout Dawadawa tree (Pakia biglobossa) that towers above 25m. Enthusiasts climb to the top of the tree using the stout and well protected ladder. The rest stops as the name implies serve as rest points and picnic site for small groups of visitors. After the trail boardwalk is the nature station which is a recreation island in the middle of a forest. The foregoing captures the attraction of Lekki Conservation Centre as a tourist attraction in Lagos, Nigeria. For insect diversity of LCC follow this link http://t.co/etVNG4AOtw