First Two Topics (Prelim) PDF - Natural Sciences Department

General Zoology August 2024 Natural Sciences Department Introduction to General Zoology Presented by Jae Rosie Anne Banuag General Zoology Natural Sciences Department Content...

General Zoology August 2024 Natural Sciences Department Introduction to General Zoology Presented by Jae Rosie Anne Banuag General Zoology Natural Sciences Department Content Evolutionary Perspective Ecological Perspective Specialization of Zoology System of Classification Fundamental Properties of Life August 2024 The Microscope General Zoology Natural Sciences Department General Zoology Zoology : Study of Animals Broad field that requires zoologists to specialize in one or more subdisciplines General Zoology Natural Sciences Department Zoology: An Evolutionary Perspective All animals share a shared evolutionary history and have been shaped by similar evolutionary forces. Evolutionary Processes are simple in nature but have led to a vast diversity of life. Approximately 4 to 10 million animal species exist today; over 1 million have been described. Around 90% of animal species that ever existed are now extinct. To understand animals and their origins, zoologists need to study evolutionary processes. General Zoology Natural Sciences Department Zoology: An Evolutionary Perspective Organic Evolution: Change in the genetic makeup of populations over time, explaining animal diversity and family relationships. Darwin's Contribution: Published evidence of evolution in 1859 and proposed a mechanism that is now central to understanding evolutionary change. Evolution explains why animals look and function as they do and clarifies their family relationships within the animal kingdom. General Zoology Natural Sciences Department Zoology: An Ecological Perspective Principles help us understand how animals interact within those environments. Human overpopulation is at the root of virtually all other environmental problems. It stresses world resources and results in pollution, climate change, deforestation, and the extinction of many plant and animal species. General Zoology Natural Sciences Department Specialization of Zoology Sub disciplineDescription Anatomy Study of the structure of entire organisms and their parts. Cytology Study of the structure and function of the cells. Ecology Study of the interaction of organisms with their environment. Embryology Study of the development of an animal from the fertilized egg to birth or hatching. Genetics Study of the mechanisms of transmition of traits from parents to offspring. General Zoology Natural Sciences Department Specialization of Zoology Histology Study of tissues. Molecular Biology Study of sub cellular details of animals structure and function. Parasitology Study of animals that livein or other organisms at the expense of the host. Physiology Study of the function of organisms and their parts. Systematics Study of the classification, and the evolutionary inter relationships among, animal groups. General Zoology Natural Sciences Department Specialization of Zoology Histology Study of tissues. Molecular Biology Study of sub cellular details of animals structure and function. Parasitology Study of animals that livein or other organisms at the expense of the host. Physiology Study of the function of organisms and their parts. Systematics Study of the classification, and the evolutionary inter relationships among, animal groups. General Zoology Natural Sciences Department Specialization of Zoology Ethology Study of behavioural science Entomology Study of insects Herpetology Study of amphibian and reptiles Ichthyology Study of fishes General Zoology Natural Sciences Department Specialization of Zoology Mammology Study of mammals. Ornithology Study of birds Protozoology Study of protozoa General Zoology Natural Sciences Department System of Classification Binomial nomenclature: Two-part scientific names (e.g., Perissodus microlepis) Hierarchical classification: Domain > Kingdom > Phylum > Class > Order > Family > Genus > Species. General Zoology Natural Sciences Department Fundamental Properties of Life Each organism possesses chemical uniquenes Four Major Categories biological macromlecules: Proteins Carbohydrates Lipids Nucleic Acids General Zoology Natural Sciences Department Fundamental Properties of Life Organisms are made up of one or more cells. All living things are made up of cells. Some are unicellular, like amoeba, while others, like your body, are multicellular. General Zoology Natural Sciences Department Fundamental Properties of Life Organisms react and respond. react to stimuli, whether they are external or internal. General Zoology Natural Sciences Department Fundamental Properties of Life Organisms grow and develop. Growth is simply define as the increase in mass. It is made possible by process that involve the intake of substances from the external environment and their eventual incorporation into inner structure of the organism. General Zoology Natural Sciences Department Fundamental Properties of Life Organisms need nourishment. All living organisms require nourishment to survive, grow, and thrive. This nourishment comes in various forms—such as food, sunlight, or nutrients—and is essential for maintaining vital biological processes, supporting energy production, and enabling overall development. Without proper nourishment, organisms cannot sustain life or reproduce effectively. General Zoology Natural Sciences Department Fundamental Properties of Life Organisms reproduce. Reproduction involves the reproduction of genetic materials which shall be passed to the next generation. Reproduction is a must for a species to continue to exists. General Zoology Natural Sciences Department Fundamental Properties of Life Organisms expend energy. Organisms constantly expend energy to perform essential life processes, such as movement, growth, reproduction, and maintaining homeostasis. This energy, derived from nutrients or sunlight, powers cellular activities and enables organisms to respond to their environment, repair damage, and sustain their existence. Without energy expenditure, life functions would cease, leading to the organism's decline. General Zoology Natural Sciences Department Fundamental Properties of Life Organisms excrete wastes and toxic materials. General Zoology Natural Sciences Department Fundamental Properties of Life Organisms evolve. Organisms evolve over time, adapting to their environment through genetic changes that enhance survival and reproduction. General Zoology Natural Sciences Department History of the Microscope General Zoology Natural Sciences Department Robert Hooke (1665): Improved the compound microscope. Observed cork cells and named them "cells" in his book Micrographia. Antonie van Leeuwenhoek: Perfected the simple microscope with single lens. Discovered bacteria and protozoa, calling them "animalcules." Observed spermatozoa and dental plaque. General Zoology Natural Sciences Department Robert Brown ( 1831) observed cells with a central part nucleus Felix Dujardin (1835) observed that cells are not hollow but filled with thick fluid or “juices” within the cell Johannes Purkinjie (1839) gave the term protoplasm to designate the “juices” inside the cell. This is actually the living substance of the cell which contain essential elements General Zoology Natural Sciences Department 19th Century Advances: Theodore Schwann and Mattias Schleiden advanced cell theory for animals and plants. Schwann and Schleiden initially misunderstood cell growth. Rudolf Virchow (1855) confirmed that all cells come from existing cells. observed how cells grow and divide General Zoology Natural Sciences Department The Microscope A microscope is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy. Microscopic means invisible to the eye unless aided by a microscope. General Zoology Natural Sciences Department Light Microscope SIMPLE COMPOUND Provides a three- Uses multiple lenses dimensional view of and visible light to larger or opaque magnify specimens. specimens using reflected light. General Zoology Natural Sciences Department Types of Microscope Electron Microscope Transmission Electron Microscope (TEM): Uses electron beams transmitted through a specimen to achieve high- resolution images of internal structures. Scanning Electron Microscope (SEM): Uses electron beams scanned over a specimen's surface to create detailed three- dimensional images of external features. General Zoology Natural Sciences Department Types of Microscope Confocal Microscope: Utilizes laser light and a pinhole to create high-resolution, three- dimensional images of specimens by focusing on thin layers. Fluorescence Microscope: Uses fluorescence to visualize specimens that are labeled with fluorescent dyes, highlighting specific structures or molecules within cells. General Zoology Natural Sciences Department Types of Microscope Confocal Microscope: Utilizes laser light and a pinhole to create high-resolution, three- dimensional images of specimens by focusing on thin layers. Fluorescence Microscope: Uses fluorescence to visualize specimens that are labeled with fluorescent dyes, highlighting specific structures or molecules within cells. General Zoology Natural Sciences Department Types of Microscope Phase Contrast Microscope: Enhances contrast in transparent specimens without staining by converting phase shifts in light passing through the specimen into changes in brightness. Dark Field Microscope: Uses a special condenser to produce a dark background with brightly illuminated specimens, useful for viewing live, unstained samples. General Zoology Natural Sciences Department Types of Microscope Phase Contrast Microscope: Enhances contrast in transparent specimens without staining by converting phase shifts in light passing through the specimen into changes in brightness. Dark Field Microscope: Uses a special condenser to produce a dark background with brightly illuminated specimens, useful for viewing live, unstained samples. General Zoology Natural Sciences Department Types of Microscope Polarizing Microscope: Utilizes polarized light to view specimens that are birefringent, such as minerals or certain biological tissues, enhancing contrast and detail. Atomic Force Microscope (AFM): Uses a probe to scan the surface of a specimen and measure interactions at the atomic level, providing high-resolution topographical images. Super-Resolution Microscope: Employs advanced techniques (such as STED or SIM) to surpass the diffraction limit of light, allowing for higher resolution imaging of cellular structures General Zoology Natural Sciences Department Cell as a Unit of Life General Zoology Natural Sciences Department What are Cells? Functional units of life. Site for all chemical reactions necessary for life. Smallest independent units of life. General Zoology Natural Sciences Department Three Theories of the Cell: 1. All living things are made up of cells 2. The cell is the smallest unit of life 3. Cells come from the division of pre-existing cells General Zoology Natural Sciences Department Cells Exhibit different shapes: E.coli – rod shape Paramecium- slipper like shape Amoeba – irregular form that changes shape as it moves General Zoology Natural Sciences Department Cells Exhibit different shapes: General Zoology Natural Sciences Department Types of Cells: Prokaryotic Cells: Lack nuclei and membrane-bound organelles. Classified into two domains: Archaea and Eubacteria. Simpler structure; "before nucleus." General Zoology Natural Sciences Department Types of Cells: Eukaryotic Cells: Have a membrane-bound nucleus containing DNA. Contain various organelles that perform specific functions. Larger and more complex than prokaryotic cells. Include animals and protists. Have a cytoskeleton made of microfilaments and microtubules for shape and intracellular movement. General Zoology Natural Sciences Department 3 Basic parts of Eukaryotic Cells: 1. Plasma Membrane: a. Outer boundary of the cell b. Separates internal metabolic events from the environment c. Contains receptors for external molecules General Zoology Natural Sciences Department 3 Basic parts of Eukaryotic Cells: 2. Nucleus: pl., nuclei a. Cell's control center b. Contains chromosomes c. Separated from cytoplasm by nuclear envelope d. Filled with semifluid nucleoplasm General Zoology Natural Sciences Department 3 Basic parts of Eukaryotic Cells: 3. Cytoplasm a. Gr. kytos, hollow vessel + plasm, fluid b. Portion of the cell outside the nucleus c. Semifluid portion of the cytoplasm is called the cytosol. d. Suspended within the cytosol are the organelles. General Zoology Natural Sciences Department Cell Membranes: Structure 1. Phospholipid Bilayer: a. Phospholipids have polar (hydrophilic) heads and nonpolar (hydrophobic) tails. b. Polar heads face the cell exterior and cytoplasm; nonpolar tails face inward, avoiding water. General Zoology Natural Sciences Department Cell Membranes: Structure 2. Cholesterol: a. Embedded in the membrane, making it less permeable to water-soluble substances. b. Stabilizes the membrane with its rigid structure.  General Zoology Natural Sciences Department Cell Membranes: Structure Membrane Proteins: a. Peripheral proteins are attached to the membrane surface. b. Intrinsic proteins are embedded within the membrane.  General Zoology Natural Sciences Department Cell Membranes: Structure Membrane Proteins: c. Functions include linking to sugar-protein markers, transporting ions/molecules, and connecting the membrane to the cytoskeleton or external molecules. General Zoology Natural Sciences Department Cell Membranes: Structure Glycocalyx: a. Formed by glycoproteins and glycolipids on the membrane surface. b. Acts as a molecular "fingerprint" for cell recognition and behavior. c. Essential for cell-to-cell interaction and coordination in animals. General Zoology Natural Sciences Department Cell Membranes: Function Cell membranes functions: Regulate movement of materials in and out of the cell and within the cell. Separate the cell's interior from the exterior environment. Divide different organelles within the cell. Provide a large surface area for specific chemical reactions. Distinguish cells from one another. Act as a site for receptors with cell identification markers. General Zoology Natural Sciences Department Movement across membranes Passive Transport Simple Diffusion: Molecules move from high concentration areas to low concentration areas. Movement continues until molecules are evenly distributed (dynamic equilibrium). This process is called simple diffusion (L. diffundere, "to spread"). Simple diffusion is key for short- distance transport in and out of cells. General Zoology Natural Sciences Department Movement across membranes Facilitated Diffusion: Polar molecules diffuse through protein channels in the lipid bilayer. Channels provide a pathway for these molecules to cross the membrane without interacting with the hydrophobic layer. Large molecules like glucose and amino acids use facilitated diffusion, needing no energy. In facilitated diffusion, molecules temporarily bind to a carrier protein and move from high to low concentration. General Zoology Natural Sciences Department Movement across membranes Osmosis Special type of diffusion diffusion of water across a selectively permeable membrane from an area of higher concentration to an area of lower concentration Water Flow: Water can cross cell membranes despite its polarity, but the flow is limited. Aquaporins: Specialized water channels that facilitate water flow in living cells. General Zoology Natural Sciences Department Types of Solution: Isotonic solution- there is no net movement of water; the solute concentration is the same on both sides of the membrane; there is no net gain or loss of water (iso-means the same) water moves across the plasma membrane ate the same rate in both directions. General Zoology Natural Sciences Department Types of Solution: Hypertonic solution Solute concentration is higher outside the cell rather than it is inside Water moves out of the cell and make the cell shrinks. General Zoology Natural Sciences Department Types of Solution: Hypotonic solution the solute concentration is lower outside the red blood cell than it is inside. the concentration of water molecules is higher outside the cell than it is inside. As a result, water moves into the cell, which swells and may burst General Zoology Natural Sciences Department Active Transport: requires a protein carrier and the use of cellular energy (ATP). Proteins involve which often called pumps. The movement of molecules is from lesser to greater concentration General Zoology Natural Sciences Department Bulk Transport: Endocytosis Plasma membrane envelopes large particles and molecules and moves them in bulk across the membrane. General Zoology Natural Sciences Department Bulk Transport: Phagocytosis (solid particles) the engulfing and ingesting of foreign particles by phagocytes (cell eating) Pinocytosis (fluid) the ingestion of fluid into a cell by turning a portion of the cell membrane inward to form a sheath that is then pinched off to form an internal vesicle (cell drinking) General Zoology Natural Sciences Department Bulk Transport: Exocytosis the secretory vesicles fuse with the plasma membrane and release their contents into the extracellular environment General Zoology Natural Sciences Department Cytoplasm, organelles, and cellular components Cytoplasm Content inside the cell membrane gelatinous consists of different molecules dissolved in water refers to the content inside the cell membrane including organelles and outside the nucleus The content of the nucleus is called as nucleoplasm Both cytoplasm and nucleoplasm are collectively called as protoplasm General Zoology Natural Sciences Department Cytoplasm, organelles, and cellular components Nucleus Controller of Cells the largest organelle in most cells with a membrane (nuclear envelope) that keeps the content of the nucleus (nucleoplasm) and separate from the cytoplasm. the membrane connected to nuclear envelope is the endoplasmic reticulum with pores in the nuclear envelope that allow large molecules to pass into and out of the nucleoplasm. General Zoology Natural Sciences Department Cytoplasm, organelles, and cellular components Nucleus with chromatin (thread like materials) that condenses into rod like structure (chromosomes) at the time the cell divides. The DNA and histones are packaged into chromosomes Nucleus contains DNA which carry genetic materials. DNA directs protein synthesis and it is this function that makes the nucleus the control center of the cell in which the proteins help determine its structure and General Zoology Natural Sciences Department Cytoplasm, organelles, and cellular components Ribosomes non-membrane bound structures site for protein synthesis contains almost equal amounts of protein and a special kind of ribonucleic acid called rRNA Some attach to the ER and some float freely in cytoplasm General Zoology Natural Sciences Department Cytoplasm, organelles, and cellular components Endoplasmic Reticulum (Transporter of Molecules) Complex, membrane-bound structure with sheets, sacs, and tubules. Extends from the nuclear envelope to the plasma membrane. Functions as a network for material circulation in the cytoplasm. Storage site for enzymes and proteins. General Zoology Natural Sciences Department Cytoplasm, organelles, and cellular components Rough ER: Has attached ribosomes. Involved in protein synthesis. Smooth ER: Lacks ribosomes. Functions in lipid production, detoxification, and calcium ion storage. Most cells contain both rough and smooth ER, with proportions varying by cell type. General Zoology Natural Sciences Department Cytoplasm, organelles, and cellular components Golgi Apparatus (Processor and Packager) Discovered by Camillo Golgi in 1898. Consists of flattened, membrane-bound cisternae (fluid-filled spaces). Works closely with the ER. Functions: Sorts, packages, and secretes proteins and lipids. Receives proteins in transfer vesicles from the ER. Concentrates and chemically modifies proteins. Marks and sorts proteins for different destinations. Packages modified proteins into secretory vesicles. Vesicles release contents outside the cell via exocytosis. General Zoology Natural Sciences Department Cytoplasm, organelles, and cellular components Lysosome (digestion and degradation) Membrane-bound, spherical organelles. Contain enzymes called acid hydrolases. Digest organic molecules (lipids, proteins, nucleic acids, polysaccharides) in acidic conditions. Enzymes are synthesized in the ER. Processed in the Golgi apparatus. Secreted as lysosomes or vesicles that fuse with lysosomes. Fuse with phagocytic vesicles to digest their contents. General Zoology Natural Sciences Department Cytoplasm, organelles, and cellular components Mitochondria Double-membrane-bound organelles. Shape: Spherical to elongated. Outer Membrane: Covers the entire organelle. Inner Membrane: Folds to form cristae (partitions) that increase surface area for reactions. Matrix: Space between cristae, containing ribosomes, circular DNA, and other materials. Function: Convert energy to a usable form ( cellular respiration), known as the cell's "power generators." Multiply when cells need more energy. General Zoology Natural Sciences Department Cytoplasm, organelles, and cellular components Vacuoles (storer of molecules) Both plants and animals have vacuoles, but they are much prominent in plant cells. Water storage – contractile vacuole Food storage and waste products- food vacuole Filled with water, sugar and salts, pigments and toxic substances. It maintains internal hydrostatic pressure (turgor) within the cell and maintain acidic internal pH General Zoology Natural Sciences Department Cytoplasm, organelles, and cellular components Centrosome organizer of microtubules of the animal cell as well as a regulator of cell cycle absent in the plant cell contain pair centriole that forms the spindle fibers during cell division which guide the movement of chromosomes General Zoology Natural Sciences Department Cytoplasm, organelles, and cellular components Cytoskeleton (shape and motion) helps maintain the cell’s shape, anchors the organelles and allows the cell and its organelles to move Cilia and Flagella : Movers of the Cell Hairlike extensions of cells Ex. Paramecia move by means of cilia Sperm and euglena move by means of flagella