Download Bio21 Diversity Lab

DIVERSITY IN LIVING THINGS
Classification and General Characteristics
Life on this planet includes a diverse array of representatives. It is difficult to learn much about living
things in general by studying organisms one at a time, but if we group them together according to their
similarities, general information about them becomes apparent. Humans have used these generalities
to develop a classification scheme that is intended to represent the historical degree of relatedness
among the organisms. Because data about organisms (especially, lately, genetic data) is continually
collected, this human-deduced scheme is subject to change.
In this exercise, we will study representative samples from most of the broad classification categories
in use today. Our goals are to be able to recognize representatives by their group characteristics, and to
connect significant group characteristics with their place in evolution. To help you organize your study
of these organisms, a checklist of questions to ask about each organism is provided. Please take
time and work with your classmates to answer all the questions list below. Accompanying slides are in
the ppt file Diversity Lab.ppt.
1. Common name or description
2. Sketch or description (so you can remember it. Include size.)
3. Ecological niche (e.g.: aquatic or marine, moist land, desert, etc. This is usually related to
structures of the organism.)
4. Nutritional habit (e.g. heterotrophism by ingestion, saprophytic heterotroph, autotrophic by
photosynthesis. In multicellular Eukaryotes, this is related to Kingdom.)
5. Domain and Kingdom
6. Phylum or Division or other descriptor.
7. Additional levels of classification for: Arthropods, Chordates, Flowering plants
8. Eukaryotic or Prokaryotic (should match Domain)
9. Single or multi-cellular (also connect to size)
10. Do its cells have a nucleus and other organelles? (connect to Domain)
11. Can the cell respire? (connect to Domain – there are two for this one)
12. Does the cell contain mitochondria? (answer by Domain – just one qualifies)
13. Can the cell photosynthesize? (answer by color and kingdom/Domain)
14. Does the cell contain chloroplasts? (three Kingdoms in one domain qualify)
15. Does the cell have a cell wall? (answer by Kingdom)
16. What is the cell wall made of? (Kingdom)
17. Can the organism form cilia or flagella? (only part of one Domain is included.)
Developing General Concepts:
1. Write a sentence for each Domain, then for each Kingdom, describing the general
characteristics for organisms in that group.
2. Describe the characteristics shared by all photosynthesizing organisms, then divide them into
two major groups.
3. Describe the differences between Prokaryotic and Eukaryotic cells.
4. Describe the theory of endosymbiosis: the method of evolution of Eukaryotic cells from
Prokaryotic and Archaean ancestors.
1
CLASSIFICATION OF LIVING THINGS
I. Domain Archaea
The cells of these single-celled, microscopic organisms look like those of Prokaryota and will be
treated as though they are the same for most applications. Their metabolism shows evidence of the
earliest evolution of metabolic pathways, and their genes show close relationships with the outer cell of
Eukaryota. They reproduce asexually by binary fission. Two subdivisions of this group are:
1. Crenarchaeota – sulfur-dependent anaerobes, can probably oxidize molecular hydrogen,
most are extreme thermophiles although some low temperature types are known. Includes
chemoheterotrophs, acidophiles, and photoautotrophs.
2. Euryarchaeota – halophiles, thermophiles, and methanogens. Includes heterotrophic
anaerobes and chemoautotrophs. Closely related to ancestors of Eukaryota.
II. Domain Bacteria
The cells of these single-celled, microscopic organisms lack a nucleus (they have a somewhat dense
nuclear region called a nucleoid) and other organelles. Their internal membrane is limited to the
precursors of grana found in some Cyanobacteria.
Eubacteria include oxygen-respiring bacteria related to mitochondria.
Cyanobacteria are oxygen photosynthesizers related to chloroplasts.
Reproduce asexually by binary fission. Some recombination occurs.
Solitary, unicellular, filamentous, colonial, or mycelial
Non-motile or motile by gliding or by bacterial flagella.
Cell walls of murien (peptidoglycan).
III. Domain Eukarya
The cells of these possess a nucleus, mitochondrion, and other organelles. They are always capable of
oxygen-based respiration (unless secondarily lost). The outer cells are apparently descended from
Euryarchaeota while the mitochondria and chloroplasts are descended from Bacteria. It has been
proposed, but not widely accepted, that the nucleus and cytoskeleton also have components descended
from extinct Bacteria or Archaea.
A. Kingdom Protista (probably five or more kingdoms)
Single-celled aquatic organisms.
Absorptive (heterotrophic) or photoautotrophic by photosynthesis in plastids.
Aerobic unless lost secondarily
All forms can reproduce asexually. Meiosis and fertilization occur in some.
Unicellular, colonial unicellular, or multicellular (algae)
All lack embryos and complex cell junctions (desmosomes).
Most have centrioles and can form flagella or cilia in the 9 + 2 pattern.
Some have cell walls made of cellulose.
2
B. Kingdom Fungi
Multicellular sessile organisms including mushrooms and molds.
Heterotrophic, always by absorption (saprophytic).
Aerobic (or infrequently anaerobic).
Cells are haploid or diploid. Propagation by haploid spores.
Meiosis occurs in zygote. Fertilization by conjugation.
Mycelial organisms or secondarily unicellular.
Body plan is often branched into hyphae, some divided by septae.
No endocytosis. Extensive cytoplasmic streaming.
Most cells lack centrioles.
Chitinous cell walls.
C. Kingdom Plantae
Multicellular sessile organisms whose cells all have cellulose cell walls.
Autotrophic by photosynthesis in chloroplasts.
Aerobic in mitochondria.
Meiosis and fertilization. Diploid phase develops from embryo.
Multicellular haploid phase present (alternation of generations).
Advanced tissue differentiation.
Some lack centrioles.
Partial Plant Kingdom Classification:
Division Bryophyta (mosses)
Division Pterophyta (ferns)
Division Coniferophyta (cone-bearing evergreens, called gymnosperms)
Division Anthophyta (flowering plants, angiosperms)
Class Monocotyledoneae (parallel veins in leaves, flowers in 3 or 6 parts)
Class Dicotyledoneae (palmate veins in leaves, flowers in 4 or 5 parts)
D. Kingdom Animalia
Aerobic, motile multicellular organisms, heterotrophic by ingestion.
Meiosis and fertilization. Typically lack a haploid phase.
Multicellular, motile through cytoskeleton motors.
Extensive cellular and tissue differentiation.
Lack cell walls.
Complex connections between cells (gap junctions and desmosomes)
All cells have centrioles. May form flagella and cilia with 9 + 2 structure.
3
Partial Animal Kingdom Classification:
Phylum Porifera (sponges)
Phylum Cnidaria (jelly fish, sea anemones)
Phylum Platyhelminthes (flat worms)
Phylum Nematoda (round worms)
Phylum Annelida (segmented worms)
Phylum Mollusca (clams, octopus, snails)
Phylum Arthropoda (jointed legs)
Class Crustaecea (lobsters, crags)
Class Arachnida (spiders)
Class Insecta (insects)
Phylum Echinodermata (starfish, sea urchin)
Phylum Chordata
Subphylum Vertebrata (backbones)
Fish (jawless, sharks and bony fishes)
Class Amphibia
Class Reptilia (lizards, turtles)
Class Aves (birds)
Class Mammalia (humans, furry animals)
You MUST bring this lab manual in order to do the lab. PowerPoint file is optional.
Your textbook will be helpful for this lab.
4