Diversity of living things quiz 1

• Species


  All organisms capable of breeding freely with each other under natural conditions
• Hybridization


  The cross-breeding of two different species
• Morphology


  The physical appearance and characteristics of an organism; also the science of the study of these physical characteristics
• Evolutionary changes


  A change that occurs in an entire population; usually occurs over a long period of time
• Genetic diversity


  The genetic variability among organisms; usually referring to individuals of the same species
• Heterotroph


  An organism that obtains energy rich nutrients by consuming living or dead organisms
• Autotrophs


  An organism that uses sources of energy to produce nutrients from water, gases and/or minerals
• Species diversity


  A measure of diversity that takes into account the quantity of each species present, as well as the variety of different species present
• Structural diversity


  The range of physical shapes and sizes within a habitat or ecosystem
• Loss of biodiversity threatens our food supply, eliminates sources of natural medicines and potential new medicines, has a significant economic impact on tourism and forestry when accompanied by habitat destruction, and has the potential to cause serious disruptions in biogeochemical cycles
• Taxonomy


  The science of systematics, the science of classifying organisms
• Taxonomy was developed by Carl Linnaeus (1707-1778)
• Taxonomy is based on anatomical & physiological characteristics, and the more features organisms have in common, the closer their relationship
• Biological classification


  The systematic grouping of organisms into biological categories based on physical and evolutionary relationships
• 7 Main Taxa


  • Kingdom
  • Phylum
  • Class
  • Order
  • Family
  • Genus
  • Species
• Acronym to help remember the 7 Main Taxa: (kids prefer cookies over fried green spinach?)
• Taxon


  A category used to classify organisms
• Rules for Binomial Nomenclature: Name consists of two words - Genus and species, both words are underlined or italicized, Genus is always capitalized, species is always lower case, Both names are always in latin or latinized, Two different organisms cannot have the same name, The species name has to be different within the same Genus
• Prokaryotes


  A single celled organism that does not contain a membrane bound organelle
• Eukaryotes


  Any organism whose cells contain organelles; some eukaryotic organisms are single celled, while others are multicellular
• Domains of Life


  Carl Woese identified 3 domains (highest taxonomic level) of life: Eubacteria, Eukaryota & Archaea
• Human Taxa


  • Domain- Eukaryotic
  • Kingdom - Animalia
  • Phylum- Chordata
  • Class- Mammalia
  • Order- Primates
  • Family- Hominidae
  • Genus - Homo
  • Species - Homo sapiens
• Phylogeny


  The history of evolution of organisms, often shown in a phylogenetic tree with branching that leads to descendants from the most ancestral form
• Clade


  A taxonomic group that includes a single ancestor species and all its descendants
• Dichotomous key

  A classification manual that gives two choices in each step to identify an organism
• In constructing dichotomous keys, the first step should divide the organisms in roughly half, choices should be positive, both choices of a pair should be about the same attribute, each pair of choices should be about a different attribute, each attribute should only be used once, measurements should be used instead of terms like large/small, and there should be one less step than there are total organisms to classify
• Bacteria are present everywhere - on surfaces, in air, in soil, on and in living organisms, and may have been the first living cells (3.5 billion years ago)
• Archaebacteria


  Primitive bacteria that often live in environments where most other organisms cannot survive
• 3 major subgroups of Archaebacteria

  • Methanogens (methane-producing organisms)
  • Extreme Thermophiles (organisms that thrive in temperatures up to 110°C)
  • Extreme Halophiles (organisms that live in very salty water)
  • Psychrophiles (cold-loving organisms)
• Most Archaebacteria live in anaerobic conditions
• Many bacteria have one or more plasmids (small loop of DNA) in their cytoplasm, and some are also surrounded by a sticky capsule (reduces water loss, resists high temps and helps to keep out antibiotics/viruses)
• Eubacteria can be classified by appearance

  • Spherical (cocci)
  • Rod-Shaped (bacilli)
  • Spiral (spirilla)
• Obligate Aerobes


  Bacteria that require oxygen for respiration
• Obligate anaerobes


  Bacteria that conduct respiration processes in the absence of oxygen
• Facultative anaerobes


  Bacteria that prefer environments with oxygen, but can live without oxygen
• Many bacteria can get energy from inorganic chemicals such as H, S and Fe compounds
• Binary fission


  The asexual reproduction of bacteria where the single strand of bacterial DNA replicates and the identical genetic material is transferred to each new cell
• Conjugation


  The sexual reproduction of bacteria where two cells connect and pieces of DNA (plasmids) are transferred from donor to recipient, resulting in recombination and altered characteristics
• Endospores


  Resting cells formed by some bacteria to survive unfavourable conditions, with a thickened wall around the genetic material and cytoplasm
• Bacteria are essential decomposers, produce vitamins, and inhibit the growth of other microorganisms, but can also cause disease by destroying cells and tissues and producing toxins