chelsea

• what are the two common characteristics of protist

  Most of them are abundant in moist environments

  
  

  Most of them are microscopic in size
• What are the three major ecological groups

  Algae,Protozoa ,Fungus
• Algae


  generally photoautotrophic
• Protozoa


  heterotrophic protists
• Fungus-like


  resemble fungi in body form and absorptive nutrition
• Plankton


  swimmming or floating protist,bacteria,viruses
• Periphyton


  communities of microorganisms that produce multicellular bodies
• Flagellates


  protists that move with a long whip-like structure called a flagella
• Ciliates


  A group of protozoans that move by waving tiny, hair-like organelles called cilia.
• Amoebae


  move by means of pseudopodia
• What is a protist?


  eukaryote that is not an animal, plant, or fungus
• CHARACTERISTICS OF PROTISTS


  A membrane-bound nucleus, with multiple, linear chromosomes

  
  

  Microtubules and microfilaments, in addition to cytoplasmic organelles, including mitochondria and chloroplasts

  
  

  Transcription and translation characteristics similar to other eukaryotes
• Classification of protist


  Extreme diversity

  
  

  "Kingdom" Protista is NOT monophyletic

  
  

  Paraphyletic (perhaps > 30 kingdoms)

  
  

  
  

  "catchall" taxonomy category) ¡ Protists are not prokaryotes, fungi, plants, or animals
• PROTIST HABITAT AND STRUCTURE

  Aqueous,¡ Oceans, freshwater lakes, ponds, streams, and moist soil and within host organisms,

  
  

  Unicellular or colonial with little differentiation
• diatoms


  Single-celled, covered by silica shells (diatomaceous earth) Photoautotrophs Carbon-fixing marine plankton

  Asexual and sexual reproduction Daughter cells receive different sized shell

  Zygotes secrete new shells
• brown algae


  One of a group of marine, multicellular, photoautotrophic protists, the most common type of seaweed. Brown algae include the kelps.
• Choanoflagellates


  protists that are the closest living relatives of animals
• Charaphycean


  Charophyceae is a class of charophyte green algae.
• ANCESTRY AND DIVERSITY OF MODERN PLANTS

  Kingdom Plantae •

  
  

  Multicellular eukaryotic organisms composed of cells having plastids •

  
  

  Primarily live on land

  
  

  Evolved from green algal ancestors that lived in aquatic habitats •

  
  

  Distinguished from modern algal relatives by adaptations to terrestrial life
• ANCESTRY of plantae


  originated from a photosynthetic protist ancestor that, if present today, would be classified among the streptophyte algae
• DISTINCTIVE FEATURES OF LAND PLANTS

  • Bodies composed of three-dimensional tissues

  Tissues arise from apical meristems at growing tips

  • Able to produce thick, robust bodies

  
  

  • Tissues and organs with specialized functions
• DISTINCTIVE REPRODUCTIVE FEATURES


  • Aid in survival in terrestrial habitats

  Alternation of generations: Plants exhibit a life cycle where two multicellular stages alternate: the sporophyte (2n) and the gametophyte (1n).

  Sporophyte: The diploid sporophyte produces haploid spores through meiosis.

  Gametophyte: The haploid gametophyte produces gametes (sperm and egg cells) through mitosis.

  • The sporophyte embryo is nourished and protected by maternal tissues

  Land plant sporophytes produces tough-walled nonflagellate spores that survive dispersal through dry air
• SPOROPHYTES AND GAMETOPHYTES


  The diploid generation produces spores(haploid) and is called a sporophyte.(meoisis reduction in ploidy level)

  
  

  • The haploid generation produces gametes by mitosis and is called a gametophyte(mitosis retains ploidy level)
• BRYOPHYTES


  Include liverworts, hornworts, and mosses that share common structural, reproductive, and ecological features

  
  

  • Lack vascular tissue

  
  

  Are poikilohydric (have little control over internal water content)

  
  

  • Produce flagellated sperm

  
  

  • No true roots (have rhizoids), stems, and leaves

  • Possess a cuticle and stomata

  
  

  • Gametophyte larger than attached sporophyte
• Gametangia


  produce gametes in shelter
• Archegonia


  produce eggs
• Antheridia


  produce sperm
• • Phylum Hepatophyta (liverworts)


  Leafy or simple flattened thallus (gametophyte) • No true stomata • Some have gemmae (cuplike asexual reproductive structure on thallus)
• • Phylum Anthocerophyta


  • Plantlike and algalike features • Simple flattened thallus • Long and pointed sporangium of sporophyte phase, like a horn
• Gametophytes role is


  to produce haploid gametes
• Gametophytes is produced by

  mitosis
• Gametangia


  multicellular organs that produce gametes
• Antheridia


  spherical or elongate gametangia producing sperm
• • Archegonia


  - flask-shaped gametangia enclosing an egg
• Sperm swim to egg and fuse to form a

  diploid zygote
• Zygotes grow into


  sporophytes
• SEEDLESS VASCULAR PLANTS


  lycophytes and pteridophytes
• • Lycophytes and Pteridophytes possess

  •vascular tissue(• internal water and nutrient conducting tissues that also provide structural support)
• Together, lycophytes, pteridophytes, and seed-producing plants are known


  tracheophytes(name is taken from tracheids, a type of specialized cell that conducts water and dissolved minerals and provides structural support)
• Stems


  • Produce leaves and sporangia • Contain phloem and xylem (contains tracheids and lignin)