GENERAL BIOLOGY - STEM 1ST SEM

• Biology


  The study of life or the study of living things what they are, how they function, how they interact with each other and with their environment, and how they change or evolve
• 2 Major divisions of biology

  • Botany - the study of plants
  • Zoology - The study of animals
• Fields of specialization in the study of plant and animal life

  • Morphology - the study of structures and forms of organisms
  • Anatomy - study of the internal structure of living organisms and how tissues are arranged
  • Physiology - functions and bodily processes in organisms
  • Cytology - structure and functions of cells
  • Histology - tissues
  • Embryology - growth and development of new organisms
  • Ecology - environment and the interrelationship of organisms in it
  • Taxonomy - identification, classification and naming of plants and animals
  • Genetics - heredity and variation, or how an organism's characteristics are transmitted from parents to offspring
  • Evolution - origin and differentiation of different kinds of organisms
  • Paleontology - fossils of living things and their distribution in time
  • Microbiology - microorganism
  • Bacteriology - bacteria
  • Virology - viruses
  • Protozoology - protozoans or one-celled animals
  • Biochemistry - study of chemical processes involved in living organisms
  • Biogeography - distribution of plants and animals on earth
• Related Studies in Zoology

  • Helminthology - worms
  • Ichthyology - fishes
  • Ornithology - birds
  • Mammalogy - mammals
  • Conchology - shells
  • Anthropology - man
  • Mycology - fungi
  • Phycology - algae
  • Parasitology - organisms that live and subsist on or in other living organisms
  • Pathology - nature of diseases and the structural and functional changes produced by them
  • Conservation biology - study of the preservation and protection of the natural environment and the existing living organism
  • Biophysics - study of biological processes using Physics Principles
  • Systematics - study of the diversity of and the relationship among organisms
  • Molecular biology - the study of biomolecules Provides basic information for biotechnology (genetic engineering, cloning and gene therapy
• Levels of Organization


  • Atoms - smallest unit matter that cannot be broken down into anything simpler by chemical means.
  • Molecules - the smallest unit of most compounds formed by the chemical bonding of atoms.
  • Organelles - specialized structures that perform important cellular functions within cells.
  • Cells - the smallest unit of life collections of living matter enclosed by a barrier that separates them from their surroundings.
  • Tissues - groups of similar cells that perform at particular function.
  • Organs - groups of tissues that work together to perform closely related functions.
• Microscopes


  Allowed the discovery of the tiny building blocks of life called cells
• Types of microscopes


  • Simple microscope
  • Compound microscope
  • Electron microscope
  • Stereomicroscope
  • Scanning probe microscope
• Robert Hooke first coined the term "cell" after he cut a piece of bark from an oak tree in 1665
• Contributions of Robert Hooke

  • He observed pieces of cork from the bark of a cork tree under the microscope
  • His observations led him to coin the word "cell"
  • "Cell" - means little rooms in Latin
  • He compared the small boxes to the small rooms that monks lived in
• In Filipino, the translation for the word cells is sihay, meaning "silid ng buhay"
• Anton van Leeuwenhoek


  Father of Microscopy, saw tiny living things in pond water, through his improved simple microscope he was able to discover the tiny animals (bacteria, protozoan) which he called the animalcules
• Robert Brown discovered the presence of nucleus within the cells
• Felix Dujardin said that cells contain a gelatinous fluid, a life substance called sarcode
• Johannes Purkinje


  Coined the term "protoplasm" which pertains to the living materials inside the cells
• Rudolf Albert von Kolliker


  Coined the term "cytoplasm" from protoplasm, cytoplasm is a semisolid, semiliquid substance inside the cell that holds other cellular parts (except nucleus), protoplasm includes nucleus, cytoplasm doesn't
• Theodor Schwann discovered that animals are composed of cells
• Matthias Schleiden discovered that plants are composed of cells
• Rudolf Virchow coined the statement omnis cellula e cellula, which means, "cells divide and form new cells"
• The cell theory


  • All organisms are made of cells
  • The cell is the basic unit of life
  • Cell arise from pre-existing cells
• The modern cell theory

  • The energy of organisms is formed in the cells
  • Hereditary information (DNA) is passed on from cells to cell
  • All cells have the basic chemical composition
• Unicellular Organisms


  An organism that is only made up of only one cell
• Multicellular Organisms


  An organism that is made up of more than one cell
• Eukaryotic cell


  A cell or organism that possesses a clearly defined nucleus with a nuclear membrane that surrounds the nucleus, in which the well-defined chromosomes (bodies containing the hereditary material) are located
• Prokaryotic cell


  An organism that lacks a distinct nucleus and other organelles due to the absence of internal membranes
• Types of Cells


  • Bacterial Cell
  • Animal Cell
  • Plant Cell
• Cell Membrane (Plasma Membrane)


  • Extremely delicate, thin, elastic, living and semi-permeable membrane, made up of two layers of lipid molecules in which protein molecules are floating, can be observed under an electron microscope only
• Functions of Cell Membrane

  • Maintains shape and size of the cell
  • The boundary between the cell and its external environment; and as a structure that controls the movement of substances in and out of the cell
  • It is a semipermeable membrane, that allows the entry of some substances, such as water and prevents the entry of others
• Protoplasm


  The jellylike material that encloses the cell, composed of 20% carbon, 10% hydrogen, 62% oxygen, 3% nitrogen, and 5% trace elements, capable of flowing and changing state from a semisolid gel to a semiliquid solution
• Cytoplasm


  The protoplasm lying outside the nucleus, a jelly-like material formed by 80% of water, present between the plasma membrane and the nucleus, contains a clear liquid portion called cytosol and various particles like proteins, carbohydrates, nucleic acids, lipids and inorganic ions, also contains many organelles with distinct structure and function
• Karyoplasm (Nucleoplasm)


  The protoplasm inside the nucleus
• Mitochondria


  • Small, rod shaped organelles bounded by two membranes - inner and outer, outer membrane is smooth and encloses the contents of mitochondria, inner membrane is folded in the form of shelf like inward projections called cristae, inner cavity is filled with matrix which contains many enzymes, contain their own DNA which are responsible for many enzymatic actions
• Mitochondria


  The powerhouse of the cell, synthesize energy rich compound ATP which provide energy for the vital activities of living cells
• Ribosomes


  Small granular structures made up of RNA and proteins, involved in the production of proteins in a process called protein synthesis
• Endoplasmic Reticulum


  • Network of tubular and vesicular structures which are interconnected with one another, some parts are connected to the nuclear membrane, while others are connected to the cell membrane, two types: smooth (lack ribosomes) and rough (studded with ribosomes)
• Functions of Endoplasmic Reticulum

  • Gives internal support to the cytoplasm
  • RER synthesize secretory proteins and membrane proteins
  • SER synthesize lipids for cell membrane
  • In liver cells SER detoxify drugs and poisons
  • In muscle cells SER store calcium ions
• Golgi Body


  • Discovered by Camillo Golgi, formed by stacks of 5-8 membranous sacs called cisternae, has two ends: cis face situated near the endoplasmic reticulum and trans face situated near the cell membrane
• Functions of Golgi Body

  • Modifies, sorts and packs materials synthesized in the cell
  • Delivers synthesized materials to various targets inside the cell and outside the cell
  • Produces vacuoles and secretory vesicles
  • Forms plasma membrane and lysosomes
• Vacuoles


  • Single membrane sac filled with liquid or sap (water, sugar and ions), in animal cells are temporary, small in size and few in number, in plant cells are large and more in number, may be contractile or non-contractile
• Functions of Vacuoles


  • Store various substances including waste products
  • Maintain osmotic pressure of the cell
  • Store food particles in amoeba cells
  • Provide turgidity and rigidity to plant cells
• Lysosomes


  • Small, spherical, single membrane sac filled with hydrolytic enzymes, found throughout the cytoplasm, occur in most animal cells and in few type of plant cells