CHAPTER 2 : CHAPTER 2 CELL AS THE BASIC UNIT OF LIVE Intro : Intro Cell is the basic unit of all living things. Microscope : Microscope Historians credit the invention of the compound microscope to the Dutch spectacle maker, Zacharias Janssen, around the year 1590.
Eyepiece Lens: the lens at the top that you look through. They are usually 10X or 15X power.
Arm: Supports the tube and connects it to the base
Base: The bottom of the microscope, used for support
Stage: The flat platform where you place your slides. Objective Lenses: Usually you will find 3 or 4 objective lenses on a microscope. They almost always consist of 4X, 10X, 40X and 100X powers.
How to Focus Your Microscope? Image of cells under microscope : Image of cells under microscope Onion epidemics Human cheek cell Animal Cells : Animal Cells All animals and plants are made up of cells.This diagram represents an animal cell. Most cells have:
A nucleus that controls the activities of the cell
Cytoplasm, where most of the chemical reactions take place. The reactions are controlled by enzymes
A cell membrane that controls what enters and leaves the cell
Mitochondria in the cytoplasm where respiration takes place to release energy Plant Cells : Plant Cells This diagram represents a plant cell. Plant cells also have:
A cell wall made of cellulose, which strengthens the cell and provides support
They often have:
Chloroplasts which contain the green pigment chlorophyll. This absorbs light energy for photosynthesis
A permanent vacuole filled with cell sap, which provides support Specialised Cells : Specialised Cells Different types of cells look different because they are adapted to their function. They are said to be specialised.Similar cells that carry out the same function are grouped together in tissues.
Different tissues work together in organs.
Different organs are combined together to form organ systems.
For example, muscle cells form muscle tissue. The heart contains muscle tissue, nervous tissue and connective tissue. The heart is part of the circulatory system. The Levels of Cell Organization : The Levels of Cell Organization Single Cell- smallest structural unit of an organism that is capable of independent function. Example - White Blood Cell Cell Slide 9: A group of cells that all do the same work Example - Muscle Tissue Organ : Organ A group of tissue that works together for perform a function Examples - Heart, Kidney, Lung System : System A group of organs that do a certian job. Examples - Circulatory System, Digestion System, Lymphatic System (immune System) Microorganisms : Microorganisms Structural Diagram of the Influenza Virus : Structural Diagram of the Influenza Virus Human body : Human body