CLASSIFICATION OF LIVING THINGS

Classification of living things is the sorting or grouping of living things according to their common or similar characteristics. The scientist who developed the first system of classification is called Carolus Linnaeus. All organisms cannot be classified as either plants or animals based on Carolus Linnaeus classification. Therefore, five kingdoms have been generally accepted for all living organisms, these include: Monera, Protista, Fungi, Plantae, and Animalia.

KINGDOM MONERA (PROKARYOTES)

  • They are microscopic single-celled.
  • Their cell wall does not contain cellulose.
  • They have no definite nucleus.
  • They lack most cell organelles except the ribosome.
  • Reproduction is asexual by binary fission.

KINGDOM PROTISTA

  • They are unicellular organisms.
  • They are all eukaryotes i.e. cells have a definite nucleus.
  • Most are aquatic organisms.
  • They move either by cilia, flagella or pseudopodia.
  • Some are free-living while few are parasitic.

KINGDOM FUNGI

  • They are non-green organisms
  • They lack chlorophyll so they do not photosynthesize.
  • They are non-motile except moulds.
  • They have a rigid cell wall made up of chitin and polysaccharides.
  • They reproduce asexually and sexually.
  • Most of them are saprophytes while some are parasites.
  • They lack true roots, stem and leaves.
  • Few are unicellular (yeast) while most are multicellular (rhizopus, mushroom)

KINGDOM PLANTAE

This consists of organisms with cellulose cell wall and chlorophyll for manufacturing their food. It consists of three major phyla i. e Thallophyta, Bryophyta and Tracheophyta

  1. Thallophyta (algae):Examples include spirogyra, volvox, sargassum.
  • These are simple aquatic photosynthetic plants
  • They are non-vascular plants
  • They lack true roots, stems and leaves.
  • They are either unicellular or multicellular and may be green, brown or red.
  • They reproduce asexually (by cell division, fragmentation, spore) or sexually.
  1. Bryophyta: These include hornworts, liverworts and mosses
  • They are multicellular, non-vascular plants.
  • They also lack true roots, stems and leaves.
  • They have chlorophyll as the only
  • They are multicellular, non-vascular plants.
  • They also lack true roots, stems and leaves.
  • They have chlorophyll as the only photosynthetic pigment.
  • They are terrestrial but live in moist places.
  • They produce spores asexually and also reproduce sexually.
  1. Tracheophyta:
  • They are green multicellular, terrestrial vascular plants.
  • They have tissues for conducting water and food.
  • They have true roots, stem, and leaves. They are subdivided into two i.e. pteridophytes and spermatophytes.

KINGDOM ANIMALIA

Kingdom Animalia is composed of all animals. It is the largest kingdom among the five kingdoms. The different phylum of the animal kingdom are as follows:

  • Porifera: They are commonly known as Sponges. They are non-motile multicellular organisms • They have a hard outer skeleton and porous body.
  • Coelenterata (Cnidaria): they have a hollow body cavity that is differentiated into two ends. They live in colonies (corals) as well as solitary (Sea anemone) e.g. Hydra, Jellyfish, etc.
  • Platyhelminthes: commonly known as flatworms. They have flattened body with three layers of cells. They are either free-living (Planaria) or parasitic (liver flukes).
  • Nematoda:  This Phylum consists of roundworms.  They have a cylindrical body. They are Parasitic and cause diseases such as elephantiasis, ascariasis, etc. Eg. ascaris
  • Annelida: They have a segmented cylindrical body differentiated into head and tail. Eg. Earthworm
  • Arthropoda: This phylum consists of animals with jointed appendages They have an exoskeleton and a segmented body. They have well-differentiated organ and organ systems. They have an open circulatory system, but no blood vessels. Eg grasshopper, etc.
  • Mollusca: • They are bilaterally symmetrical and triploblastic. • They have a less segmented body. They have a well-developed organ and system. They have an open circulatory system. Limbs are present. Eg snails, octopus.
  • Echinodermata: are radially symmetrical and triploblastic. They have hard skeletal structure. They are free-living marine animals. E.g starfish
  • Chordata: They are at an organ-system level of classification.They possess a notochord and a nerve cord. Examples are the vertebrates.

Lessons

HA’YHWH 🛐 YESHUA 🛐 HAMASCHIAC 🛐 SCHOOL SS3 HA’YHWH 🛐 YESHUA HAMASCHIAC 🛐 BIRTHDAY 🛐 – FIRST TERM, Biology, Lesson 2. WAEC

Length: 0 minutesAuthor: Hassan Salami

HOMEOSTASIS Homeostasis is the process by which a fairly constant internal environment is maintained in an organism. An organism’s internal environment comprises the body fluid such as blood, lymph, and tissue fluid. For efficient functions of body cells and healthy growth, a living organism must be able to adjust to any change in the physical ….  Read More

HA’YHWH 🛐 YESHUA 🛐 HAMASCHIAC 🛐 SCHOOL SS3 HA’YHWH 🛐 YESHUA HAMASCHIAC 🛐 BIRTHDAY 🛐 – FIRST TERM, Biology (Homeostasis; Liver and Skin), Lesson 3. WAEC

Length: 0 minutesAuthor: Hassan Salami

THE LIVER STRUCTURE OF THE LIVER The liver is the largest organ in the body of a mammal with a weight of about 1.25kg. It is reddish brown, soft with two lobes, and located below the diaphragm on the right side of the abdomen. It partly overlaps the stomach and has a bile duct connecting ….  Read More

HA’YHWH 🛐 YESHUA 🛐 HAMASCHIAC 🛐 SCHOOL SS3 HA’YHWH 🛐 YESHUA HAMASCHIAC 🛐 BIRTHDAY 🛐 – FIRST TERM, Biology, Lesson 4 (Hormones). WAEC

Length: 0 minutesAuthor: Hassan Salami

HORMONES AND ENDOCRINE GLANDS Hormones are chemical substances produced or secreted by endocrine glands (ductless glands) in response to various stimuli. Hormones are secreted into the bloodstream and circulated to exert their effect on their target organs. This effect could be to speed up or slow down biological reactions. Hormones are active in homeostasis, growth, ….  Read More