Cell type: prokaryotic Cell structure: Cell walls with peptidoglycan Number of cells: UNIcellular Nutrition: heterotrophic or autotrophic Examples: Streptococcus P., E. Coli Cell type: prokaryotes Cell Structures: cell walls without peptidoglycan Number of cells: UNIcellular Nutrition: mostly chemoautotrophic Examples: Methanogens; Halophiles Cell type: eukaryotes Cell structure: plant like, animal like, or fungus like Number: most unicellular; some colonial (work together in a colony) Nutrition: heterotrophic (animal and fungi like) or autotrophic (plant like) Examples: amoeba, paramecium, slime molds, algae Cell type: eukaryotes Cell structures: cell walls made of chitin Number: mostly multicellular (yeasts unicellular) Nutrition: Absorptive heterotrophs Examples: mushrooms, morels, yeasts Cell type: eukaryotic Cell structures: Cell wall of cellulose; chloroplasts; large vacuole Number: multicellular Nutrition: Photoautotrophic Examples: mosses, ferns, evergreens, flowers Cell type: eukaryotic Cell structures: no cell walls; centrioles Number: multicellular Nutrition: heterotrophic Examples: invertebrates; fish; amphibians; reptiles; birds; mammals Unicellular – organisms that consist of only a single cell ( uni- means one) Multicellular – organism that contain hundreds, thousands, or even trillions of cells (multi – means many) Colonial – organisms that work and live together in a colony. Example: Volvox *Colonial organisms are different from multicellular because individual cells will still live if they are separated from the colony. *Colonial organisms were probably the 1st step towards multicellular organisms via natural selection Taxonomy – the study of classifying organisms and assigning organisms a universally accepted name. the Greek philosopher (384-322 BC) developed the first system for classifying organisms. He divided organisms into 2 groups: Plants and Animals (1707-1778) a Swedish botanist, whose classification was based on the physical and structural appearances of organisms. He developed Binomial Nomenclature a two word naming system that uses the Genus and the Species as the scientific name. Scientific names are usually in Latin or Greek (because it was the common language) Scientific names are italicized or underlined The Genus is always capitalized, the species is lowercased Ex: Homo sapiens, Lynx rufus (bobcat) There are 8 taxa (levels) of classification based on physical characteristics and evolutionary relationships. Kingdom Phylum Class Order Family Genus Species Most inclusive (biggest) Most specific (smallest) Taxon Bobcat Lynx Domain Eukarya Eukarya Kingdom Phylum Class Order Family Genus Animalia Chordata Mammalia Carnivora Felidae Lynx Animalia Chordata Mammalia Carnivora Felidae Lynx Species Rufus Canadensis Dumb – Kings – Play – Chess – On – Flat – Green – Squares – Domain Kingdom Phylum Class Order Family Genus Species 1. Internal/external structures Fur, feathers, scales, etc. Vertebrate (backbone) or Invertebrate? Shape, size, color 2. Phylogeny The study of evolutionary relationships among organisms Chromosomal comparisons Geographical distributions How close the amino acid sequences are in proteins Method of grouping organisms together according to their evolutionary history. Biologists now group organisms into categories that represent lines of evolutionary descent, or phylogeny, not just physical similarities. is a branch of evolutionary classification that uses derived characters to classify organisms. Derived characters – characteristic that appears in recent parts of a lineage, but not in older species. A cladogram is a diagram that shows the evolutionary relationships among organisms, using derived characters. Biotic (living) Size – bigger than viruses, smaller than eukaryotes; unicellular Kingdoms – Archaebacteria, Eubacteria Nutritional requirements Archaebacteria – chemoautotrophic (use chemical reactions to get energy) Eubacteria – autotrophic (cyanobacteria) and heterotrophic (decomposers or pathogens – disease causing parasites) Reproduce asexually by binary fission Binary fission occurs when the bacteria replicate their DNA and divide into 2 identical cells. Conjugation occurs when two bacteria cells form bridges (called pili) between one another and exchange genetic material. Endospores occur when growth conditions are unfavorable. The bacterium forms a thick wall that protects its DNA. Spores can remain dormant for months or even years. Structure Prokaryotes Cell membrane and cell wall of peptidoglycan (eubacteria) Cytoplasm DNA and RNA Ribosomes Obligate aerobes – organisms that require a constant supply of oxygen to live (Ex: Mycobacterium tuberculosis the bacteria that causes tuberculosis) Obligate anaerobes – organisms that must live in the absence of oxygen (Ex: Clostridium botulinum can grow in canned food that isn’t properly sterilized) Facultative anaerobes – a group of bacteria that can survive with or without oxygen (can switch between cellular respiration and fermentation (Ex. E. Coli lives anaerobically in the large intestine and aerobically in sewage or contaminated water). Abiotic (not living) Size – much smaller than bacteria (not made of cells!) Kingdom – none (not a living organism) Nutritional requirements – no food required Reproduces in a host cell through lytic or lysogenic infection Structure Particles of nucleic acid, protein, and sometimes lipids Core made of DNA (RNA in retroviruses) Protein coat called a capsid surrounds the core Most viruses are highly specific to the cell that they infect. Plant viruses infect plant cells; animal viruses infect only certain related species of animals; and bacteria viruses infect only certain types of bacteria. Bacteriaphages – viruses that infect bacteria. Lytic infection – a virus enters a cell, makes copies of itself, and causes the cell to burst. The host cannot tell the difference between its own DNA and the viral DNA. The infected cell lyses (bursts) and releases hundreds of virus particles that can go on to infect other cells. The host cell is destroyed. Lysogenic infection – a virus integrates its DNA into the DNA of the host cell, and the viral genetic information replicates along with the host cell’s DNA. Lysogenic viruses do not lyse the host cell right away. The virus remains inactive for a period of time. The viral DNA that is embedded into the host’s DNA is called a prophage. Retroviruses – viruses that contain RNA as their genetic material. When retroviruses infect a cell, they produce a DNA copy of their RNA, which is then inserted into the host’s DNA. Retroviruses can remain dormant for long periods of time. Ex: Acquired Immune Deficiency Syndrome (AIDS) is a retrovirus. Pathogen HIV/AIDS Influenza (Flu) Smallpox Streptococcus pyogenes (Strep) Bacteria/Virus Retrovirus Effect on Body Helper T cells, which are needed for normal immune system function, are destroyed Pathogen HIV/AIDS Bacteria/Virus Retrovirus Influenza (Flu) Virus Smallpox Streptococcus pyogenes (Strep) Effect on Body Helper T cells, which are needed for normal immune system function, are destroyed Body aches, fever, sore throat, nasal congestion, headache, cough, fatigue Pathogen HIV/AIDS Bacteria/Virus Retrovirus Influenza (Flu) Virus Smallpox Virus Streptococcus pyogenes (Strep) Effect on Body Helper T cells, which are needed for normal immune system function, are destroyed Body aches, fever, sore throat, nasal congestion, headache, cough, fatigue Fever, fatigue, rash, head and back aches Pathogen HIV/AIDS Bacteria/Virus Retrovirus Influenza (Flu) Virus Smallpox Virus Streptococcus pyogenes (Strep) Bacteria Effect on Body Helper T cells, which are needed for normal immune system function, are destroyed Body aches, fever, sore throat, nasal congestion, headache, cough, fatigue Fever, fatigue, rash, head and back aches Fever, sore throat, swollen glands Biotic (living) Size – bigger than bacteria; most unicellular, some multicellular or colonial. Kingdom – Protista Nutritional requirements – autotrophic (algae) or heterotrophic Have alternating two part life cycle: diploid, spore forming sporophytes and haploid, gamete forming gametophytes. Structure – 3 groups: animal like (protozoans), plant like (algae), and fungus like. Your immune system protects you against DISEASE Disease ▪ any change, other than injury, that disrupts the normal functions of the body Germ Theory ▪ States infectious diseases are caused by pathogens (infectious agents) ▪ Ex. Viruses, bacteria, protists, worms, and fungi 2 Types of Immunity 1.Passive -Get from outside source -Ex: mother gives to fetus -Ex: mother gives to baby during breast feeding 2. Active - When your immune system works -Ex. You get sick and your body fights it off OR after you get sick you don’t get it again (like chicken pox) -VACCINES!! 1. Nonspecific - 1st line of defense - Starts with skin and mucus to trap any pathogens - Inflammatory Response - Injury causes swelling and blood rushing to a wound - Blood brings White blood cells (WBC) that “engulf” or “eat” any foreign substance - WBC actually roll along blood vessels until they get to a wound, stop and start their jobs! All antibodies look the same, Except for the top of the “Y” AKA Immune Response Triggered by Antigens: foreign substance Humoral Response B-cells produce antibodies Antibodies then remove and disrupt the antigen through various mechanisms Cell Mediated Response Used against the body’s own cells (Ex. Viral infected cells or cancer) T-cells target “bad” cells and kill them T-CELL INFECTED CELL VACCINE ALLERGIES Weakened form of a pathogen (disease) Your body then mounts a similar response Once you develop antibodies your body “remembers” that antigen and can quickly respond a second time An “overreaction” of the immune system to an antigen Allergy causing agents attach to special cells, called Mast cells, and cause the inflammatory response Mast cells release histamines which increase blood flow in that area (in addition to mucus production, sneezing and other irritations) Antihistamines are drugs that counteract the histamine produced by mast cells histamine, releasing antigen Mast cell