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BIOLOGY 1 FIRST SEMESTER: FIRST QUARTER REVIEWER LESSON 1: MICROSCOPY AND The part through which an observer looks to view a specime...

BIOLOGY 1 FIRST SEMESTER: FIRST QUARTER REVIEWER LESSON 1: MICROSCOPY AND The part through which an observer looks to view a specimen. It usually has a magnification of 10x, though THE DISCOVERY OF CELL eyepieces with 5x to 30x magnification are also available. b. Objectives Parts of a Light Microscope The main lenses that magnify the specimen being The parts of a light microscope can generally be grouped observed. Usually, microscopes have three objectives, but into three: mechanical parts, illuminating parts, and more modern ones house four or even five objectives. magnifying parts. Typical objectives have magnifying powers of 4x, 10x, 40x, I. Mechanical parts and even 100x. Parts of the microscope that are involved in giving support or strength to the instrument. These are also the parts that TIMELINE are movable and can be adjusted. YEAR IMPORTANT EVENTS a. Body tube Hans Janssen and his son, Zacharias A hollow tube through which light passes from the objective Janssen, placed multiple lenses in a tube to the eyepiece 1590 and found out that objects seen through the b. Revolving nosepiece tube appeared greatly enlarged. Holds the objectives. It can be rotated to select the Galileo Galilei invented a compound appropriate objective. The lenses must be “clicked” into 1590 microscope using convex and concave place to successfully view a specimen. lenses. c. Arm This was the first time the term Connects the base and the body tube. It serves as a handle 1625 “microscope” was used by Giovanni for carrying the microscope. Faber to refer to the compound d. Stage microscope of Galilei. The platform where the slide or specimen to be examined is Robert Hooke, an English physicist, placed. It has an opening at the center that allows light to coined the term “cell” in his publication, pass from below to the specimen. 1665 Micrographia. e. Stage clips He was the first to see a plant cell under a Holds the slide in place single-lens microscope. f. Base The part where the microscope is firmly anchored. It gives Antonie van Leeuwenhoek was the first to support to the whole microscope and is the part where the see living cells using his own single-lens 1676 microscope. illuminators are attached. g. Inclination joint He examined blood cells, yeast, and A joint found in some microscopes at which the arm is insects. attached to the pillar of the microscope. It is used for tilting Robert Brown, a botanist, who first the microscope. observed the spherical structure in plant 1827- cells. II. Illuminating Parts 1833 Noticed that pollen grains in water jiggled Parts of the microscope that provide and capture light for around called “Brownian Motion” illumination He called this structure the “nucleus” of a. Mirror the cell. Reflects light from the surroundings to the specimen on the 1839 Theodore Schwann, a zoologist, stage. The concave side of the mirror is used for natural discovered the presence of cells in animal light, while the flat side is used for artificial light. It is tissues. supported by the mirror rack. It is already replaced with a Matthias Schleiden, the botanist who light source or a bulb that provides light. 1838 concluded that all plant tissues are b. Condenser composed of cells. Concentrates the light from the light source or mirror onto Formally established Cell Theory by the object of the specimen being studied. It is located 1839 Theodor Schwann and Matthias below the stage, and it is held in place by a rack. Schleiden. c. Iris diaphragm Regulates the amount of light that reaches the specimen. It Rudolf Virchow, a physician by profession, is attached beneath the condenser. studied the growth and development of cells. III. Magnifying Parts 1855 Did a research on cancer cells and Parts of the microscope that are involved in magnifying the concluded “Omnis cellula e cellula” (All image of the specimens, including the resolution. cells are from pre-existing cells). a. Eyepiece or Ocular 1 LOVELY JUMUAD  BIOLOGY 1 FIRST SEMESTER: FIRST QUARTER REVIEWER Discovered that all cells arise from Microscopes have parts that perform specific preexisting cells. functions. The cell theory is one of the earliest Electron microscopes can magnify an object by more foundations or doctrines in the study of life. than 200,000 times its original size. Improved microscopic techniques and microscopes THE CELL THEORY helped scientists develop the cell theory. Formally established by Theodor Schwann and Cell theory is the basic unifying foundation of biology. Matthias Schleiden in 1839. Cell theory was formulated by Matthias Schleiden, The most basic tenet underlying the field of biology. Theodor Schwann, and Rudolf Virchow. One of the basic principles of biology. Cells vary in size, shape, and function. Formulated by the 3 German scientists Theodor Most cells are microscopic, and only a few are Schwann, Matthias Schleiden, and Rudolph macroscopic. Virchow. A cell’s shape is related to its function. CELL THEORY STATES: CELL NUMBER a. Cells are the smallest unit of life. All living things UNICELLULAR are composed of one or more cells. - Are made of single cell ❖ Living things are organisms that have the Example: amoeba, bacteria, chlamydomonas, ability to reproduce and grow. yeast, euglena b. Cells are the basic unit of organization of all MULTICELLULAR organisms. - Are made of million cells ❖ It has organelles that will support the cell Example: Plants and animals itself and it comes or performs vital CELL SIZE functions that are necessary for living. − Cells are extremely small therefore they can be c. Cells come only from preexisting cells. observed under a microscope. ❖ Spontaneous Generation Theory − Cells are measured in micrometers or microns. Living things come from non-living MYCOPLASMA things. - The smallest cell ❖ First Cell Organic matter or Biomolecule. MODERN CELL THEORY Modern cell theory adds two additional key points: a. Cells carry and pass on to the offspring hereditary units during cell division. ❖ Concept of Cell Division: NERVE CELL To multiply is to divide - The longest cell b. All cells are relatively the same regarding chemical composition and metabolic activity. Cell theory marked a major turning point for cell biology. By focusing on cells, biologists can answer specific questions on how life operates and discover some profound answers to these questions. OSTRICH EGG LESSON SUMMARY - The largest cell The microscope was invented in the 16th century. The earliest microscope was only capable of providing a magnification that is 10 times the original size of a specimen’s image. In 1597, Hans Janssen and Zacharias Janssen made their version of the microscope by combining two CELL SHAPE lenses in a tube. -The shape of the cell varies in different organisms. Robert Hooke is widely considered the “English The shape of a plant cell is different from that of an Father of Microscopy.” He also coined the term “cell.” animal cell. Antonie van Leeuwenhoek came up with a They may be: microscope capable of magnifying objects up to 270 Spherical times. Polygonal 2 LOVELY JUMUAD  BIOLOGY 1 FIRST SEMESTER: FIRST QUARTER REVIEWER Oval Flagellum (plural, flagella) Columnar - A long, threadlike structure that facilitates Elliptical movement in bacteria Spindle-shaped Fimbriae Cuboidal - Bristle-like fibers that are shorter than pili. It is primarily used for bacterial attachment to tissue Types of Cells surfaces. When scientists started using microscopes, two basic Eukaryotic Cells cellular architectures were discovered: prokaryotic and Eukaryotic cells are more complex than eukaryotic. prokaryotic cells. Prokaryotic Cells A typical eukaryotic cell measures 10 to 100 µm They are mostly microscopic, measuring from 1 to (MICRONS) in diameter. 10 μm (MICRONS) in diameter, and exist in They are bigger than prokaryotic cells. unicellular form (Single-celled organism). Consist of Nucleus It lacks nucleus. It can be produced sexually and asexually This term describes cells that already existed The eukaryotic cells in your body and other before the evolution of the cell nucleus. multicellular organisms vary in many aspects. It Has a nucleoid where the genetic materials are may vary in terms of size, shape, internal suspended. organization, and function. There are two groups of bacteria in terms of Animals, Plants, Protists, and Fungi. evolution—the archaebacteria and the Cell Structures and Their Functions eubacteria. EXAMPLES: Cells vary in many aspects. They vary in size, shape, and : Archaea, Cyanobacteria and Bacteria complexity. However, they are alike in a few basic EXAMPLES Parts of a Prokaryotic Cell characteristics. Every cell, except for bacteria, has three Glycocalyx main parts: the nucleus, the cytoplasm, and the cell - It helps bacteria hold onto surfaces and protects membrane. them from being engulfed by macrophages. It may CELL ORGANELLES exist as a rigid capsule or a more unstructured Cell Wall slime layer. Cell Membrane Cell wall Nucleus - A structure that confers rigidity and shape to the Ribosome cell. It is found outside of the plasma membrane Endoplasmic Reticulum (RER and SER) and is composed of peptidoglycan. Cytoplasm Plasma membrane Golgi Apparatus - A structure that prevents the loss of water and Chloroplast electrolytes inside the cell. It also prevents the Lysosomes entry of unwanted substances into the cell. Mitochondria Plasmid Cell Wall (School Gate) - A small, circular, extrachromosomal DNA molecule is found in the cytoplasm. It is separate Made of different materials (cellulose or from chromosomal DNA. peptidoglycan) depending on the type of cell Nucleoid The external or outermost layer of a plant cell - The region where DNA is concentrated Cell Membrane (School Guard) Cytoplasm Made up of a layer of fats and proteins that helps - The whole inside region of the cell where control the movement of things in and out of the chromosomes, ribosomes, and other cellular cell. inclusions are suspended Nucleus (Principal) Ribosome The nucleus is where the genetic materials (DNA) - The site where proteins are synthesized or created is located Pilus (plural, pili) The brain of the cell - It helps bacteria adhere to the surfaces of host Ribosomes (Teachers) cells. It can also be used to transfer genetic Ribosomes are micromachines that produce proteins. material from one bacterium to another, in which It reads translates genetic codes from the nucleus. case it is called sex pilus. Endoplasmic Reticulum (Hallways) 3 LOVELY JUMUAD  BIOLOGY 1 FIRST SEMESTER: FIRST QUARTER REVIEWER Is an enclosed passageway to produce and cell include ribosomes, centrioles, microtubules, transport materials such as protein. microfilaments, glycogen granules, and pigments. Rough Endoplasmic Reticulum Most eukaryotic cells have a nucleus. It houses an o Looks rough due to the presence of organism’s genetic material. ribosomes on its membrane surface. A cell Plant cells have cell walls and plastids. They also with more RER produces a large number of have larger water vacuoles than animal cells. proteins to be inserted into the Cell specialization or modification refers to the membranes or exported to the outside. process by which an ordinary or typical cell is Smooth Endoplasmic Reticulum converted into a specialized cell to do a different o SER is more tubular and nongranular due task for the body. to the absence of ribosomes. Involved in the synthesis of steroids in gland cells. Cytoplasm (Grounds and Floors) A thick, jelly-like substance inside the membrane. Most of the chemical reactions within a cell take place in the cytoplasm. Golgi Apparatus (Teacher’s Office) Moves, sorts, and package material for delivery. Chloroplast (Canteen) Contains the photosynthetic pigment chlorophyll that captures sunlight and converts it into useful energy, thereby, releasing oxygen from water. Lysosomes (Janitors) Contains enzymes that can break down substances. Responsible for cellular waste degradation and recycling. Mitochondria (Electrical Room) It is the powerhouse of the cell. Produces ATP molecules during cellular respiration. LESSON SUMMARY Cellular diversity is reflected in the different shapes and sizes of cells found in tissues. Cells are small to maximize cellular processes. Prokaryotic cells and eukaryotic cells differ greatly in terms of internal organization and parts. Prokaryotic cells lack a nuclear envelope and membrane-bound organelles. Eukaryotic cells are generally larger and have a very distinct nucleus that is surrounded by a nuclear envelope. The cell membrane, sometimes called the plasma membrane, is the outermost covering of animal cells. The materials in the cell that surround the nucleus make up the cytoplasm. Organelles are tiny structures in the cytoplasm that are surrounded by a membrane. Some organelles found in the cytoplasm include the endoplasmic reticulum, the Golgi apparatus, the mitochondrion, lysosomes, secretory granules, and lipid droplets. Cytoplasmic inclusions are non-membranous substances and structures suspended in the 4 cytoplasm. Some cytoplasmic inclusions in the LOVELY JUMUAD