CLASSIFICATION OF LIVING THINGS- TAXONOMY, KINGDOM MONERA, PROTISTA AND FUNGI. KINGDOM PLANTAE- GYMNOSPERMAE AND ANGIOSPERMMAE

On the Earth today, there are many and various types of living things existing. This great variety of life is called biological diversity or biodiversity.

Image from pixabay by abstract

To help us understand properly the great diversity of living things, we put them into groups. This grouping of similar living things is known as classification. This classification gives us a simple and proper understanding of the various types of the living things and makes it easy for us to study them detailed involving their structure, way of living and so on.

This actually lead to the Biologist to classify living things for the following reasons;

(1). To simplify their study. Like I said earlier, it helps us to make a detailed study of each living things and also to try to point the various distinguishing characteristics existing or that can be found in them.

(2). To bring order out of chaos or confusion. Imagine studying or knowing about all the living things without no grouping, it will be difficult to be able to specifically point out the differences between each or various types of living things thereby leading to confusion when studying them.

(3). To try to understand how life orginated. Dating back to classification, it gives us proper clue and information about the orgination of life including the various stages and levels involved in it.

HOW ARE LIVING THINGS CLASSIFIED

Living things are classified according to how similar they are, on or inside their bodies. They are classified if by one way or the other they exist similar physical characteristics, way of living and reaction behaviour to things as this can aid proper grouping and classification.

To give a proper illustration, animals can be out in a group together because their limbs are built on the same basic plan. That limbs has show the physical characteristics present in them which aid in grouping.

The limbs of a bat, a horse, a horse, a human and a whale all have the same basic pattern though they are used in different ways.

Originally, scientist only examined the outer(and sometimes inner) appearance or morphology of the organism. Classification was based on the degree of difference or similarity in the way they looked.

Different features- for example, the number of hairs on the leg of an insect and the arrangement of fins and scales on a fish were used to classify them. Also in this case, their similar physical characteristics (hairs, fins and scales) aid the classification

With this classification in place, In many cases, you can tell just by looking at an organism what it is- you would never mistake a lion for a cheetah, as physically they are different and even the way they behave, react also are different.

Notwithstanding, the appearance of an organism can be affected by many different things or factors and there can be a huge amount of variation within a group of closely related organisms.

Today there are more sophisticated ways of comparing organisms. As as day goes by, certain factors are rising up causing a huge variation even though they are closely grouped or classified.

The fundamentals chemicals of life- such as DNA, RNA and proteins are found in almost all organisms.

However while these chemicals are broadly similar across all species, we can find differences when the molecules are broken down into their constituent parts.

Sometimes, scientist use these differences to decide which species an organism belongs to.

WHAT IS A SPECIES

The most important unit of classification is the species. Species are defined in many different ways but the most common and widely used definition of a species is: A group of organisms that can breed successfully with one another to produce fertile offspring.

To give an illustration as I always love doing it, if we are to study it carefully, horses and donkey's look similar but the offspring produced from a horse and a donkey is a mule which is sterild.

Therefore horses and donkey's are not the same species though they might look similar.

Once a system of classification has been established, it is easy to add a new species in the right place. In classification, certain attributes and factors are put in place for proper classification and once this is established firmly, it gives and easy and simpler addition of new species in the right group depending on the attributes and factors considered.

TAXONOMY

Taxonomy is the science of classifying living organisms. Modern taxonomy is a natural classification. This means that it is based on what scientist think our evolutionary relationships.

This is important to biologist. The alternative is to use an artificial classification, which is based on similarities that are not due to the evolution of organisms.

Image from pixabay by nature

To give an illustration, we could put a plant with red flowers in one group and all animals that have wings in another group.

However this would produce groups containing very different organisms: flying animals will contain birds, bats and insects which are not very closely related at all causing confusion when studying or to distinguish them.

THE MAIN TAXONOMIC GROUPS

In the natural classification, there is a hierarchy of groups where each major group is subdivided into smaller groups.
The main groups are kingdom, phylum, class, order, family, genus, and species.

Every living organism that has been discovered and identified is classified scientifically in this way.

TAXA BACTERIUM

(1). Kingdom Prokaryotae
(2). Phylum Gracilicutes
(3). Class Proteobacteria
(4). Order (gamma subdivision)
(5). Family Entero-bacteriaceae
(6). Genus Escherichia
(7). Species Coli

SEAWEED MUSHROOM

(1). Protoctista Fungi
(2). Phaeophyta Basidiomycota
(3). Phyophyceae Hymeno-mycetes
(4). Fucales Agaricales
(5). Fucaceae Agaricaceae
(6). Fucus Agaricus
(7). Serratus Campestris

**STINGING NETTLE TIGER

(1). Plantae Animalia
(2). Angio-spermophyta Chordata
(3). Dicotyledoneae Mammalia
(4). Urticales Carnivora
(5). Urticaceae Felidae
(6). Urtica Felis
(7). Dioica Tigris

The basic unit of the system is the species. Related species are grouped together into a genus. Related genera (plural of genus) at least into larger groups and so on and so forth.

The group's former series of subdivisions or TAXONOMIC rank and each group is referred to as taxon(plural taxa).

THE GENERAL CHARACTERISTICS OF THE FIVE KINGDOMS OF LIVING ORGANISMS

A kingdom is the largest taxon and consist of all the other taxa. As every taxon comes together to form a kingdom. In the modern classification there are five kingdoms which I will been talking about below;

(1). Kingdom Prokaryotae/Monera
(2). Kingdom Protoctista
(3). Kingdom Fungi
(4). Kingdom Plantae
(5). Kingdom Animalia.

This system of classification is known as the five kingdom system. At times, we tend to confuse ourselves whether Viruses are classified in any of the above kingdoms, but Viruses are not classified in any of the above kingdoms. They are grouped separately.

This is because viruses do not have all the seven characteristics of life although most scientists now classify them as living organisms.

I'll be discuss about the main characteristics of the organisms found in each of the five kingdoms below:

(1). KINGDOM MONERA

The monera include all the bacteria as well as the blue green algae. The members of the kingdom are all single-celled organisms which can also be called the unicellular ; they do not have a separate nucleus (they are prokaryotic).

They are microscopic and they reproduce by splitting in two. Some can make their own food without not depending on others by photosynthesis, but many of them are heterotrophic meaning that they cannot make their own food as they depend on others for their food.

As we have bacteria that are harmful so also we have bacteria that are useful.
Some bacteria act as pathogens and cause diseases. However many other bacteria are useful, such as those in the soil and in our gut.

Monera are involved in the carbon cycle and the nitrogen cycle and in all the processes of decay.

(2). KINGDOM PROTISTA(PROTISTA)

All the protista are microscopic single-celled organisms that do not have a nucleus-they are eukaryotic cells. They can be quite complex in shape.

The protista include plant-like organisms that photosynthesize and animal-like organisms that feed on other organisms. Some protista can move around(they are mobile), but others cannot.

Protista make up much of the plankton found in the oceans which is the basis of the food supply for all the organisms in the sea. Some protista cause serious disease in humans and animals. For example, plasmodium falciparum, which causes malaria, Entamoeba histolyca which causes amoebic dysentery and trypanosoma, the blood parasite which causes sleeping sickness.

(3). KINGDOM FUNGI

For many years now, the fungi were classified as a sort of plants. However, fungi cannot make food by photosynthesis, however as one of the major characteristics of plant is that they make their own food by photosynthesis, so they do not really fit in the plant kingdom. Biologists now understand the differences between fungi and true plants, idea for the founder of a kingdom of their own.

The fungi are a large and very successful group. There are around 80, 000 species. They vary in size from single-celled yeast to enormous puffballs.

Fungi are eukaryotic and usually multicellular. They are heterotrophic (Feed on other organisms), either absorbing nutrient directly from their food or secreting enzymes to digest their food outside of the fungus and then absorbing the nutrients.

Many fungi are saprotrophs, which means they feed off dead material.

Saprophytic fungi usually produce large numbers of spores, which float on the wind to other dead material. They play a vital role within ecosystems as decomposers.

Examples are rhizopus, mucor and penicillium (the fungus that produces the antibiotic penicillin).

RHIZOPUS

Rhizopus is a saprophytic fungus (mould) that grows on food particularly food and old bread. This gives it the common name bread mould.

It consist of a mass of branching filaments called hyphae. Together, the mass of hyphae are called a mycelium.

Individual hypae are very thin and are barely visible to the naked eye.

they go over the surface of the food and some penetrate into the food to gain nutrients. These are known as rhizoids or feeding hypae.

They will use enzymes that break down the food, which is then absorbed into the body of the fungus.

Rhizopus only becomes obvious once it starts to reproduce. It can reproduce sexually and asexually. Most commonly, the fungus a producers asexually.

The mycelium produces sporangiophores that contain a spore case or sporangium at the top.

These spores cases become darker as they mature and eventually appeared as black spot on the food.

Spores form inside and, when they are dispersed, each spore can start a new mycelium.

Sometimes, two hypae torch and fuse in sexual reproduction to form a zygospore, which contains genetic information that is a mixture from both parents. This sexual reproduction usually takes place where conditions are difficult, because they can survive two periods of drought and start going again when conditions improve.

it is important to have a system of classification of organisms to allow accurate communication between scientist. classification is based upon evolutionary relationship which can be called a natural classification.

Classification involves a hierarchy of groups, the largest group is known as the kingdom. organisms are placed within each kingdom by observation of features common to that kingdom.

PLANTAE

The kingdom plantae comprises the plants. This ranges from the tiny Mosses to the giant trees. Botanist are scientist who study plants.

They have identified around 300,000 living plant species. More than 80% of these are flowering plants.

plant are very important they are the source of the fossil fuel coal and through photosynthesis, they provide food and oxygen for all other living organisms.

We use plants to provide us with food, building materials, clothing, medicines, and many other things.

CHARACTERISTICS OF PLANTS

The main characteristics of all plants are below;

(1). They have eukaryotic cells
(2). They are multicellular organisms
(3). They contain chlorophyll and carry out photosynthesis
(4). They are predominantly land-dwelling
(5). Most have a waxy cuticle which helps prevent drying out
(6). they are non mobile they don't move their whole bodies around.

The kingdom plantae consist of non-flowering plants and flowering plants. They include the mosses, the ferns, the conifers(for example pines) and the true flowering plants(for example oil plants, yam plants).

MOSSES AND LIVERWORTE(BRYOPHYTA)

These are the simplest land plants. They do not have a true root system, so they cannot reach water under the soil or anchor themselves very firmly to the ground.

They are non vascular (do not have veins) and so I cannot transport food or water around the body of the plant. they are small the largest specie is less than 60 cm tall and are found in damp places. A large percentage of them live in tropical rainforests.

Most plant have simple slender stems. they also have thin, simple leaves which are only one cell thick(and are therefore useful for looking at under a microscope).

Mosses also have simple rootlike structures called rhizoids that have slender filaments and attached the Mosses to the soil, but without any strength.

The other example is the liverworts, which only grow in very wet places. Mosses are commonly found in rainforest and at high altitude on mountains.

Liverworts are also members of the Bryophta and are only found in very wet places

**FERNS(PTERIDOPHYTA)

Ferns have true leaves, stems and roots. The two generation exist as separate plant but the sporoohyte is large and dominant.

Fern steps have rhizomes that grow horizontally just below the surface of the soil. Their stems contain vascular tissue similar to that found in flowering plants, and so do their roots. They produce spore-forming bodies on the underside of the fronds.

The spores are dispersed by wind. However, they still rely on water for reproduction which limit where they can live.

Most ferns live in damp, shady places. They are very common in tropical rainforest where conditions are ideal for their Growth. However, some ferns, such as pteridium spp(commonly known as bracken), are an exception because they can grow in full sunlight.

Another example of a pteridophyte is the fern Dryopteris spp. There are a number of different Dryopteris ferns in Nigeria in the mountainous area.

The seed bearing plant or spermatophyte are the most successful and common of all land plants for the following reasons;

(1). They have well-developed root stem and leaves.
(2). They have well-developed vascular tissues
(3). The male gametes are contained within polygons and their female gamete is contained within the embryo sac.
(4). The product of fertilization in sexual reproduction is a seed that may or may not be enclosed in a fruit.

Thee spermatophyte are divided into two divisions namely Gymnospermae and Angiospermmae

CONIFERS(GYMNOSPERMAE)

These are the conifers or naked seed plant. Pine trees, spruces and cedars are just some of the more common conifers. They go around the world about one-third of the world Forest are coniferous.

Image from pixabay by Cornwall

They are often cultivated for timber are some of them are relatively fast growing. They are usually the dominant vegetation in cold and mountainous regions. Some conifers have developed relatively fleshy tissue around their fruit(for example juniper and yew), but the majority produce bare cones.

The main characteristics of the gymnospermae I am going to be listing below;

(1). Their seeds are not enclosed in fruits
(2). They have small needle-shaped leaves with a thick waxy cuticle which reduce water loss and minimise damage by excess heat or cold.
(3). They are evergreen so they can photosynthesis all year round
(4). The reproductive structures/flowers are found in cones.

The main cone form huge of numbers of pollen grains that areblown by wind to a female cone. Fertilization result in a small, winged seed.

The genus Pinus(for example, Pinus sylvestris Pinus resinosa, Pinus radiata) is a good example of a conifer. Members of this genius grow all around the world. They are evergreen they maintain their leaves throughout the year even in temperate climate.

This means the shed and replace a few leaves all the time, rather than spending part of the year leafless and dormant.

Conifers have been ported and planted in West Africa because of the importance as a source of timber and for ornamental purposes. look for some conifers around homes schools and hotel compounds and check it out and try to access their characteristics.

TRUE FLOWERING PLANTS (ANGIOSPERMMAE)

The flowering plants are the biggest group of land plants on the Earth. They have their reproductive structures carried in flowers. The biggest flowers in the world belong to Rafflesia arnoldii and they can be as much as a metre across.

The smallest belong to Wolffia globosa and they are less than 2 mm across. Whatever size the flowers are, they carry the reproductive part of the plant.

The main characteristics of the angiosperms are listed below;

(1). They have flowers as reproductive organs.
(2). They have their seeds enclosed in a fruit
(3). They have well-developed xyle. and phloem tissue.

SUB-DIVISIONS OF THE FLOWERING PLANTS

Flowering plants are subdivided into two main classes according to the number of cotyledons they have in their seeds. These classes are monocotyledons and dicotyledons.

MONOCOTYLEDONS(MONOCOTS)

The monocotyledons(MONOCOTS) are a group of enormous importance because they include cereal plants that form the staple diet of most of the world population. So are the grasses, which feed the domestic herbivores that supply so many cultures with meat and milk. The grasses also feed many of the wild herbivore, such as buffalo and different types of antelope that live in Nigeria and beyond.

Palms including the oil palm are also MONOCOTS.

The main characteristics of the monocotyledons are listed below;

(1). The embryo as a single seed leaf (cotyledon)
(2). Leaves are generally long and thin with parallel veins.
(3). The stem contains scattered vascular bundles
(4). In general, monocots do not reach great sizes(palms are the exception to this).
(5). They are often wind pollinated. Common examples of monocot plants including grasses orchids and maize.

Maize(Zea Mays) Ihas been used for food and animal fodder by people for centuries. Oil palms are also monocots. They are very important economically around the world including in Nigeria.

Yams are another important example of monocots, which are used for food. yams are true monocots, but their leaves look more like dicot leaves.

Some monocots can become pests. For example, the duckweeds, lemna, are very small water plants which grow and reproduce extremely fast. They can cover large areas of water and caused the death of many other aquatic organisms.

However they can also be farmed to provide fodder for animals.

The plant reproduce so fast that they can be harvested every day. Another Monocot water plant that can grow very fast and choke waterways is pistia, the water lettuce or water cabbage.

DICOTYLEDONS(DICOTS)

Most of the trees vegetables and colourful flowering plant that will know are dicotyledons (dicots). the main characteristics of the dicotyledonous are listed below;

CHARACTERISTICS OF DICOTYLEDONS

(1). The embryo has two seed leaves (cotyledons)
(2). Their lives are often relatively broad and have a network of veins.
(3). The stem contains a ring of vascular tissue
(4). Some dicot reach great sizes.
(5). They are often insect-pollinated.

Some common examples of dicot include bird of paradise flowers, peas and beans.
Most twins such as Jacaranda, mahogany, iroko and oranges are dicotyledons. Dicot shrubs include Hibiscus, Costus spectabilis and neem plants.

CONCLUSION

I will be stopping here for today and in my next post, I will be talking about the animal kingdom. I hope you enjoy this article.

Feel free to drop your comment below

REFERENCES..

. https://www.softschools.com/science/biology/classification_of_living_things/

. https://www.britannica.com/science/taxonomy/A-classification-of-living-organisms

. https://byjus.com/biology/protista/

. https://byjus.com/biology/monera/

.https://byjus.com/biology/kingdom-fungi/

. http://www.biology4kids.com/files/plants_moss.html

. https://www.toppr.com/guides/biology/biological-classification/kingdom-plantae/

. https://en.m.wikipedia.org/wiki/Fern

. https://simple.m.wikipedia.org/wiki/Conifer

. https://encyclopedia2.thefreedictionary.com/Angiospermae

. https://www.britannica.com/plant/monocotyledon

. https://www.britannica.com/plant/dicotyledon