Diversity of Living Things Flashcards
Define Classification
Organize information. It’s important:
1. To examen similarities
2. Evolutionary trends and relations
3. Where to place new species
Taxonomy
Classification system created by Carolus Linnaeus. He introduced the Kingdoms.
What are the six kingdoms?
- Anamailia
- Plantae
- Fungi
- Protista
- Monera
- Archaea
Taxons
The seven levels of classification were created by Linnaeus. They are:
1. Kingdom
2. Phylus
3. Class
4. Order
5. Family
6. Genus
7. Species
Binomial Nomenclature
2-name system. Must identify Genus and species. Genus must be capitalized, species lowercase
Dichotomous Key
Writing down opposing characteristics in couplets. Try to identify one, then move on to the next characteristic.
Phylogeny
Evolutionary history. Value of phylogeny:
- View similar species transmitting diseases.
- Medical value
Cladistics
Type of phylogeny. Uses cladograms to illustrate phylogenic trees.
Kingdom Monera
Bacteria.
- Prokaryotic cells
- Contains a Nucleoid, cell membrane, wall and capsule, flagella and pilus
- No membrane-bound organelles
- Can be an autotroph or heterotroph
- Aerobic or anaerobic
- Reproduce asexually or sexually
- Most contain plasmids (pieces of DNA), beneficial for antibiotic resistance
Classifying Monera by Appearance
By shape:
- Cocci - Round
- Bacillus - Rod-like
- Spirili - Spiral
Prefixes:
Diplo - in pairs
Staphylo - in clusters
Streplo - in chains
Peptidoglycan
A protein-based substance in the cell wall that kingdom monera contains. Discovered by Hans Gram, created the Gram Stain.
Gram-positive: thick layer of protein, pink
Gram-negative: a thin layer of protein, purple
Reproduction of Kingdom Monera
Asexually - Binary Fission:
- Chromosome replicates
- Cytoplasm pinches
- 2 cells are created
Sexually - Conjugation
- Sexual pilus is extended and a plasmid crosses into the bacteria
Kingdom Archaea
The oldest organisms.
- Prokaryotic
- Mostly anaerobic
- Mostly autotroph
- Reproduce through binary fission and conjugation
How are Archaea and Monera different
- Their lipids are arranged differently
- 3 types of RNA polymerase (enzyme)
- Live in harsh environments
- Have no peptidoglycan
3 types of Archaea and the harsh environments they inhabit
- Methanogen - take in CO2, N2 and hydrogen sulphide to create methane. Found in swamps, marshes and intestines.
- Halophiles - love saline. Found in oceans and volcanic sea vents.
- Thermophiles/thermoacidophiles - Love hot and acidic environments. Found in hot sulphur springs
Kingdom Fungi
- Eukaryotic
- Heterotrophs
- Mostly multicellular, some unicellular
- Closest to animals
- Lack chlorophyll
- Cell walls made of chitin
- Contains hyphae, thread-like filaments, mycelium is a large hyphae mass
- Reproduce by spores(sexually) and budding(asexually)
- Saprophytes feed on decaying matter
- Some are parasytes
4 Phylums of Fungi
- Sporangium / Zygospore Fungi - Mold
- Club Fungi - mushrooms, bracket fungi, puffballs
- Sac Fungi - Yeast, cup fungi, mildew
- Imperfect Fungi - ringworm, athlete’s foot, blue cheese, penicillin.
Kingdom Protista
- Mostly unicellular
- Heterotrophic
- Eukaryotic
- Reproduce through binary fission
- Found in water
Separated into 3 groups based on nutrition:
- Animal-like heterotrophs, Protozoa
- Plant-like autotrophs, Algae
- Fungus-like heterotrophs, Slime and Wtaer-moulds
Protozoa
4 phyla based on locomotion:
1. Flagellates: move by flagella
2. Sarcodates: move by pseudopodia (cytoplasmic extension)
3. Cilliates: move by cilia
4. Sporozoans: use spores
Algae
6 phyla based on pigmentation:
3 multicellular- red, brown, green
3 unicellular- diatoms, dinoflagellates, euglenoids
Slime and Water Moulds
Have characteristics of fungi, protozoa and plants. Difficult to classify.
Viruses
- Very small, measured in nanometers
- No cellular structures
- No organelles or metabolism
- Viruses contain DNA or RNA
- Viral RNA (retrovirus) uses an enzyme called Reverse Transcriptase to turn into viral DNA (provirus)
- Bacteriophages attack bacteria
- Viruses are non-living, no organelles or metabolism
- Viruses are living because they reproduce
- Only have a Nucleotide (DNA or RNA) and a Capsid (protein coat).
How are Viruses classified?
- Shapes, all are different
- Sizes
- Which nucleic acid do they contain
- Diseases they cause
How do Viruses reproduce?
Litic cycle:
- A virus attaches to a cell
- Its nucleic acid is injected into the cell
- Virus multiplies in the cell
- Cell bursts and the cycle repeats
Lysogenic cycle (dormant stage):
The virus uses reverse transcriptase to incorporate into DNA. It lays dormant until triggered by an outside force, then it will go through the lytic cycle.
