2.4.1 Cell Structure and Function (Structured Question 1 & 2)

Question 1:Diagram below shows a plant cell as seen under an electron microscope.(a)(i) On the diagram, label the structures A, B, C and D. (2 marks)(a)(ii) State the function of structure A and structure D. (2 marks)(b) Explain the role of C to maintain cell turgidity. (2 marks)(c) Every somatic cell which contains structure B … Read more

2.2.2e Involvement of Systems in Maintaining an Optimal Internal Environment

Internal Environment of Multicellular OrganismThe internal environment of a multicellular cell is referring to the medium surrounding the cell.It consists of blood plasma and interstitial fluid. (also called the extracellular fluid)HomeostasisHomeostasis is the property of a system, especially a living organism, that regulates its internal environment so as to maintain a stable, constant condition.Factors Affecting … Read more

2.2.2d Organ System

Different organ work together form an organ system.The human body has eleven different organ system, namely theCirculatory SystemDigestive SystemReproductive SystemEndocrine SystemNervous SystemRespiratory SystemMuscular SystemSkeletal SystemExcretory SystemLymphatic System (Immune System)Integumentary SystemCirculatory SystemOrgan: Heart, Blood VesselFunction: Transport nutrients, gases and wastes to and from cells, helps fight diseases and helps stabilize body temperature and pH to maintain … Read more

2.2.2a Cell

Cell specialisationCell specialisation means division of labour among cells. Each type of cell specialises in a specific function.Importance of Cell SpecialisationCells can perform specific task with greater efficiency.Enable multicellular organisms adapt to various environment.Cell Specialisation in Animal Cell Function Red blood cells Transport oxygen White blood cells Destroy microorganisms. Engulf foreign substance in the blood … Read more

2.2.2 Multicellular Organism

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

2.2.1a Unicellular Organism – Amoeba sp

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

2.2.1 Unicellular Organism

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. 

2.2 Cell Organisation

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

2.1.3 Relation between the Density of Organelles and the Function of Cells

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

2.1.2 Comparison between the Animal Cell and Plant Cell

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