Cell Biology and Organisation

Multicellular organisms are organisms that consist of multiple cells (more than one cell).Multicellular organisms are more complex than unicellular organisms and hence  need many different types of cell to carry out their life processes.This can be achieved through cell specialisation and cell organisation.Examples of multicellular organisms are hydra, spirogyra, weeds, flowering plants, vertebrate and invertebrate animals.(Hydra)(Image … Read more

General CharacteristicAmoeba sp. have no fixed shape.Their shape changes as they move.They have protrusions called pseudopodium used for movement and capturing victims.(Image by Pearson Scott Foresman shared under Creative Commons Attribution-Share Alike 3.0 Unported license.)HabitatAmoeba sp. live in water.MovementAmoebas have protrusions called pseudopodium used for movement and capturing victims.Pseudopodium is an extension of cytoplasmVideo below … Read more

Unicellular organisms are simple organisms consisting of only one cell.Each cell is a complete unit of life that is able to carry out all the living processes.The main groups of unicellular organisms are bacteria, archaea, protozoa, unicellular algae and unicellular fungi.Two important unicellular organisms that you need to know in SPM biology are the Amoeba sp. and Paramecium sp. 

Unicellular and Multicellular OrganismIn general, organisms are divided into two types: unicellular organismsmulti-cellular organisms.Unicellular organisms are the organism with just 1 cell.Each cell is able to carry out all the functions of life independently.Examples of unicellular organismParameciumAmoebaYeastChlamydomonasMulticellular organisms are the organism made up of more than 1 cellThey are larger organisms that contain many different types of cell … Read more

Density of OrganelleDensity of organelle is refering to the abundance of certain organelles found in a cell.The density of an organelle in a cell is related to the specific function of the cell.Below are examples of high density of certain organelle and their reason.Cell with high density of chloroplast.Palisade mesophyll cellReason:To trap sunlight to synthesise … Read more

Similarities of Animal Cell and Plant CellBoth animal cells and plant cells haveplasma membranenucleus with nucleic bounded by nuclear membranecytoplasmribosomemitochondriagolgi apparatusendoplasmic recticulumDifferences between Animal Cells and Plant Cells Animal Cells Plant Cells Cell Wall Absent Present Cytoplasm Present throughout the cell. Present, but usually confined to a thin layer at the edge of the cell. Chloroplast Absent Present Vacuole … Read more

Each cell consists of a plasma membrane and protoplasmThe protoplasm consist of cytoplasm and nucleus.Cytoplasm contains many types of organelles.The following is the illustration of the animal cell and plant cell.(Animal Cell)(Plant Cell)Non-OrganellePlasma MembraneThe plasma membrane separates the content of the cell from its external environment.It regulates the movement of substances entering and leaving the … Read more

Theory of CellThe cell is the basic unit or building block for all living organisms.All organisms are made up of one or more cells .Cells are the fundamental and structural unit of life.A cell is made up of a plasma membrane which contains protoplasm.Protoplasm is made up of cytoplasm and a nucleus.A cell consist of … Read more

Question 1:State arrangement of sequence in the organisation of cells in a multicellular organism. Answer:Cell –> Tissue –> Organ –> System –> Multicellular organism Question 2:The skin is the largest organ in the body. Why is skin classified as an organ? Answer:Skin is classified as an organ because skin is made up of epithelial tissues, … Read more

Question 1:State the components of cells found in high density in cells that secrete protein products. Answer:Rough endoplasmic reticulum, ribosomes and Golgi apparatus. Question 2:Briefly describe the structure and function of the nerve tissue. Answer:A nerve tissue is made of cell body and nerve fibres that are called dendrites and axons. Nerve tissues coordinate and … Read more