Classification of living things

Classification is defined as the arrangement of living things into groups based on structural genetic and cellular organization.  This is called TAXANOMY.The system of classification of living things  used today is based on that introduced by Swedish naturalist named Carl Von Linne(1707-1778).His name was better known in Latin as Carolus Linnaeus.He published the classification of plant 1753 and that of animal in 1758.

Living things are first separated into large group called KINGDOM. The division of kingdom smaller group called PHYLA (PHYLUM). The term division rather than phylum is usually used for plant. Phyla are divided into smaller groups called CLASSES. Each class is further divided into ORDER. Orders are further divided into smaller unit called FAMILIES. Families are again divided into GENERA (genius). A genius is broken into SPECIES. A species is a population of related organism that can interbreed within themselves to produce a fertile offspring. Genius is a group of closely related species. A family is a group of genera. An Order is a group of related families. A class is a group of related order. A phylum is a group of related classes. A kingdom is a group of related phyla.

Living things according to modern classification system which is based on physiology, biochemistry and embryology are classified into five kingdoms; MONERA, PROTOCTISTA, FUNGI, PLANTAE AND ANIMALIA.

MONERA (Characteristics.    They lack organized DNA i.e. the Deoxyribonucleic acid (DNA) is scattered in the cytoplasm an not in nucleus hence they are called prokaryotes.

1. They have no mitochondrion in their cytoplasm

iii.        Their cell wall lack cellulose, their cell wall is made up of protein and fatty materials

1. They are microscopic single called organism
2. Some are motile while some are non-motile
3. They feed both auto tropically and heterotrophic ally. Blue green bacterium & blue green algae

vii.       The reproduce only by asexual mean.

KINGDOM PROTOCYISTA (Characteristics)

1. They have well organized DNA in the nucleus bounded by nuclear membrane hence they are called eukaryotes
2. They are single called organism or unicellular organism

iii.        Some are motile while some are non-motile

1. They live in water, damp soil, leaf litter and other terrestrial habitats that have sufficient moist.
2. All protists use mitochondrion for cellular respiration
3. They form cyst to survive adverse condition

vii.       They all reproduce both sexually and asexually Examples are Amoeba, Euglena, Chlamydomonas, Plasmodium.

Example of Monera are:  bacteria and photosynthetic blue green bacterium also known as blue green algae.

KINGDOM FUNGI (Characteristics)

1. They all feed heterotrophic ally because they lack chlorophyll therefore cannot photosynthesize.
2. They are simple multicellular organism that grow like plant but are not plant because they are not green in colour.

iii.        Their bodies are not divided into true root, stem and leaves

1. They are mostly non-motile organisms composed of thread-like multinucleate hyphae collectively known as mycelium
2. They reproduce by means of spores. Spores are unicellular microscopic structure that is capable of germinating to a new organism.
3. The fungi stores carbohydrate as glycogen just like animal not as starch as done by plant

vii.       Their cell wall is made up of chitin and not cellulose like plant

Examples are Mucor, Rhizopus, Mushroom and Slime mould.

KINGDOM PLANTAE (Characteristic)

1. They are multicellular and non-motile organisms
2. Their cells are bounded by rigid cellulose cell walls external to cell membrane

iii.        They contain chlorophyll that enables them to manufacture their own food by photosynthesis

1. Most plants store carbohydrates as starch or sucrose.