Biodiversity

• Biodiversity


  • The variety of life on earth
  • Includes all life forms-from the unicellular fungi, protozoa and bacteria to complex multicellular organisms such as plants, birds, fishes and animals
  • The variety of flora and fauna on this planet earth
• Levels of Biodiversity


  • Different kinds of organisms (species diversity)
  • Genetic information that organisms contain (genetic diversity)
  • Different kinds of places where organisms live and the interconnections that bind these organisms together (ecosystem diversity)
• Classifying and Naming Organisms

  • Organisms which have more similarities would then, be closely related than those which have less similarities
  • Classifications or categories consist of the domain, kingdom, phylum, class, order, family, genus and species

  
• With the information available about organisms from the early studies to the present, scientists came up with the three-domain system of classification

  
• Binomial system of classification


  Scientific names are in the Latin language and are italicized
• Six-kingdom classification


  • Archaebacteria
  • Eubacteria
  • Protist
  • Fungi
  • Plant
  • Animal
• Autotrophic organism


  • Live in freshwater habitat are mostly photosynthetic
  • Blue-green algae
  • Reproduce by binary fission, others by fragmentation or budding
• Archaea Domain: Kingdom Archaebacteria


  • There are two phyla with about 217 species
  • Cannot make their own food: heterotrophs
  • Saprotrophs- they obtain their nutrients from decaying organic matter
  • Parasitic and can cause many diseases
  • Microscopic organisms
  • Reproduce by binary fission of a single cell into two cells
• Bacteria Domain: Kingdom Eubacteria


  • Cannot make their own food: heterotrophs
  • Saprotrophs- they obtain their nutrients from decaying organic matter
  • Parasitic and can cause many diseases
  • Microscopic organisms
  • Reproduce by binary fission of a single cell into two cells
• Plant kingdom


  • Multicellular eukaryotes
  • Photosynthetic and have cell wall
  • Non-vascular plants- lack vascular tissues; their bodies are described as thallus
  • Vascular plants- complex and consists of network of vascular tissues that run throughout the entire plant body
• Bryophytes


  • Terrestrial plants
  • Live in a very damp and shady places
  • Do not have vascular tissues
  • Examples: liverwort, hornwort, mosses

  
• Vascular plants


  • Classified as: vascular seed plants and vascular seedless plants
  • Xylem- carries water
  • Phloem – food transport
• Vascular Seed Plants


  • Plants produce seeds
  • Classified as: gymnosperm and angiosperm
  • Gymnosperm- plants whose seeds are not part of the fruit; cone-bearing plants
  • Angiosperm – plants which seeds are part of the fruits; also known as fruit-bearing plants; classified into monocot or dicot

  
• Poriferans


  • The simplest animals, belong to Phylum Porifera
  • Live in shallow and deep oceans
  • Body supported by a "skeleton" called spicules, made of either glasslike silica or calcium carbonate
• Cnidarians


  • Members of Phylum Cnidaria
  • Consist of animals whose tentacles contain stinging cells called nematocysts
  • Used for defense and to capture prey or food
  • A coral reef is where fishes and other marine organisms breed
• Platyhelminthes


  • Flatworm group belongs to Phylum Platyheminthes
  • Flat and ribbonlike organisms
  • Found in freshwater, in wet places and marine waters
  • Planaria is an example of a free-living flatworm
  • Flukes are parasites that live in other animals including humans
  • Tapeworms are also parasitic flatworms like flukes without a digestive system
• Nematodes


  • Roundworms are members of Phylum Nematoda
  • Long, cylindrical and slender bodies
  • Some are free-living while others are parasites of animals and plants
  • Heartworms can infect dogs and cats
• Annelids


  • Also known as annelids, these animals are characterized by a segmented or repeated body parts
  • Found crawling in moist soil or swimming in sea and freshwaters
  • Examples: earthworms, polychaetes and leeches
  • Have complex respiratory, reproductive, circulatory, digestive and excretory systems functioning together for their survival
• Mollusks


  • Soft-bodied invertebrates with most of them covered by a shell
  • Body has three parts: a muscular foot for locomotion, a mantle that produces the shell, and the visceral mass that contains their internal organs
  • Consist of three classes: the Gastropods, Bivalves and Cephalopods
• Echinoderms


  • All found in a marine environment
  • Parts of most radiate from the center of the body
  • Have spines which are extensions made of hard calcium, forming an internal skeleton called the endoskeleton
  • Examples: sea lily, sea cucumber
• Arthropods


  • Considered the most successful of all animal phyla as they are present in almost all types of habitats
  • Have an exoskeleton
  • Crustaceans: water fleas, crabs, shrimps, lobsters and barnacles; have hard exoskeletons and have mandible to bite and grind food; most live in water
  • Arachnids: have two body sections, most with four pairs of legs and mouthparts called chelicerae and pedipalps; use book lungs to respire; spiders are the largest members
  • Myriapods: close relatives of insects have long, wormlike segmented bodies; have a pair of antenna and each segment bear a pair or two legs; live in the soil, under rocks or rotting logs and leaves
  • Insects: the largest group among arthropods; have three body sections, three pairs of legs, a pair of antenna and one to two pairs of wings; reproduce rapidly
• Rainforest has the highest biodiversity
• The North Pole and certain deserts are examples of ecosystems with low biodiversity
• Factors that destroy or endanger biodiversity

  • Habitat destruction
  • Invasion of introduced species
  • Population increase
  • Pollution
  • Overcollection/overharvesting of resources