Exam 2: UNDERSTANDING DIVERSITY, CLASSIFICATION, VIRUSES, PROKARYOTES, PROTISTS & FUNGI Flashcards
Taxonomy
the branch of science concerned with the classification of organisms based on shared traits/characteristics
a system of classification: DKPCOFGS
Domain ex. eukarya (MOST GENERAL)
Kingdom ex. Animalia
Phylum ex. Chordata
Class ex. Mammalia
Order ex. Primates
Family ex. Hominidae
Genus ex. homo
Species ex. sapiens LEAST GENERAL (most specific)
ex. Human: homo sapien sapiens (subspecies of homo sapien)
What are the 5 kingdoms?
These are living organisms:
Monera, Protista, Fungi, Plant, Animal
Created by the following criteria:
- presence or absence of a nuclear membrane within the cell
- unicellularity vs multicellularity
- type of nutrition
there are currently more than 2 million different species described & named to date
binomial nomenclature
the modern system of naming organisms devised by Carl Linnaeus 1707-1778, a Swedish botanist and explorer
ex. Musca domestica : housefly
ex. Homo sapien : human
ex. Canis lupus : gray wolf
ex. Ursus horribilis : grizzly bear
most organisms will be named by (G)enus and (s)species (note that the Genus is uppercase the species is lowercase)
classification sequence from greatest to smallest
Kingdom Phylum Class Order Family Genus Species
KPCOFGS
(Domain),
Kingdom,
Phylum,
Class,
Order,
Family,
Genus,
Species
family tree diagrams
viruses
(virion) are subcellular a particle that consists of:
- DNA or RNA genome
- surrounded by a protein coat called the CAPSID
- not considered “living” according to the cell theory
monera
(bacteria) have primitive cell structures LACKING A NUCLEAR MEMBRANE
protista
(protozoa) & (algae) predominately unicellular with animal-like or plant-like characteristics
fungi
cells are usually organized into branched, multinucleated filaments, which absorb digested food form their environment
Structures & Functions of viruses
Virus Structure:
- cannot metabolize on their own
- contain nucleic acids necessary to make copies of themselves
- but must invade and use the metabolic machinery of living cells in order to reproduce
Some Examples of viruses
Animal Viruses
Viral Diseases
- DNA viruses cause smallpox, herpes, respiratory infections, gastrointestinal disorders
- RNA viruses cause influenza, upper respiratory infections, AIDS, some types of cancers
ex. RUBELLA is an RNA virus, commonly known as GERMAN MEASLES. the name is derived from Latin, LITTLE RED
Plant Viruses
Symbiotic Relationships of viruses
Types of Nutrition of viruses
Type of Respiration of viruses
Where are viruses found
VIRUSES may be bits of nucleic acids that originally “escaped” from animal, plant, or bacterial cells
Types of Locomotion of viruses
Types of Reproduction of (life cycles) viruses
***LYTIC CYCLE: virus destroys the host cell
TEMPERATE VIRUSES: do not always destroy their hosts
***LYSOGENIC CYCLE: viral genome replicated along with host DNA
TWO Viral Phases:
the lytic cycle involves the reproduction of viruses using a host cell to manufacture more viruses; the viruses then burst out of the cell
the lysogenic cell involves the incorporation of the viral genome into the host cell genome, infecting it from within
the good ones (beneficial) viruses
the bad ones (disease causing) viruses
Structures & Functions of monera
Some Examples of monera
E. coli (bacillus, rod shaped)
Symbiotic Relationships of monera
Types of Nutrition of monera
Type of Respiration of monera
Where are monera found
Types of Locomotion of monera
Types of Reproduction of (life cycles) monera
Monera reproduces asexually by binary fission during favorable conditions or endospore formation during unfavorable conditions.
They reproduce sexually by a process called conjugation.
the good ones (beneficial) monera
the bad ones (disease causing) monera
Structures & Functions of protista
Some Examples of protista
amoebas, spirogyra, and euglenoids
Symbiotic Relationships of protista
Protists are free-living or symbiotic
symbiotic relationships range from MUTUALISM TO PARASITISM
Types of Nutrition of protista
Protists can be HETEROTROPHIC, AUTOTROPHIC, or BITROPHIC
Type of Respiration of protista
Where are protista found
mostly live in aquatic environments, oceans, freshwater ponds, lakes, streams, etc.
parasitic protists live in the body fluids of hosts
ex. Plasmodium causes Malaria; trypanosomes cause African Sleeping Sickness (TSE TSE fly)
Types of Locomotion of protista
pseudopodia - how amoeba move; cytoplasmic; false feet; endocytosis and eat by phagocytosis
flagella - whip-like structures; one, two, or three
cilia - paramecium; footprint shapes, has ciliates
some are nonmotile
Types of Reproduction of (life cycles) protista
Many protists reproduce sexually and aesexually
other reproduce only asexually
the good ones (beneficial) protista
the bad ones (disease causing) protista
paramecium
virus diagram
Domains
Domain ARCHAEA (prokaryotes)
- cell walls have peptidoglycan (proteins)
- do not have membrane-bound organelles
Domain BACTERIA (prokaryotes)
- cell walls DO NOT have peptidoglycan (no proteins)
- unicellular and microscopic
- lacks a nucleus and has a plasma membrane
Domain EUKARYA (eukaryotes; 4 kingdoms)
- have a nucleus
- protista, fungi, plantae, and animalia
Kingdoms
Monera
Protista
Fungi
Plantae
Animalia
Phyla
based on structure
Classes
Orders
Families
Genera
Species
a group of organisms that are similar in structure and can mate and produce fertile offspring (can reproduce with each other but can’t with others)
why are viruses not really living?
they dont come alive until they have a host
why is euglena hard to classify?
they are a protist and have both plant and animal characteristics
amoeba
(protista) use cytoplasmic extensions (pseudopodia) to move and obtain food by phagocytosis
- entamoeba histolytica (a protozoan that causes intestinal amebiasis as well as extra-intestinal manifestations)
- parasitic amoeba and cause amoebic dysentery (diaherria)
classification
in order to study the unity and diversity of living things in an organized manner, biologists must classify organisms
there is disagreement with the best classification system but we group organisms into 5 kingdoms, and each kingdom is divided into PHYLA and so on
PHYLA
categories that indicate major differences in structure among organisms
taxonomy
the science of naming describing and classifying organisms
euglenoids
have flagelloid, are one-celled, and make/take in food
with dislike crsitae in mitochondria
- some are photosynthetic (bi-trophic) and reproduce asexually (equally by binary fission)
TRYPANOSOMA - causes African sleeping sickness
Structures & Functions of fungi
eukaryotic heterotrophs and cell walls with CHITIN
they secrete digestive enzymes onto food and then absorb predigested food
unicellular YEAST
filamentous, multicellular MOLD
most multicellular fungi: have long, threadlike filaments (HYPHAE) and branch and form a tangled mess (MYCELIUM)
HYPHAE: perforated SEPTA (cross walls) divide hyphae into individual cells
Some Examples of fungi
yeast, bread mold, and mushrooms
Symbiotic Relationships of fungi
Types of Nutrition of fungi
decomposed nutrients from their surroundings are absorbed into the fungi as nutrients
Type of Respiration of fungi
Where are fungi found
Types of Locomotion of fungi
Types of Reproduction of (life cycles) fungi
most reproduce sexually and asexually by nonmotile SPORES (produce aerial hyphae and land in a suitable spot and germinate)
Most fungi reproduce by forming spores that can survive extreme conditions such as cold and lack of water. Both sexual meiotic and asexual mitotic spores may be produced, depending on the species and conditions. Most fungi life cycles consist of both a diploid and a haploid stage.
the good ones (beneficial) fungi
the bad ones (disease-causing) fungi
plants
non-vascular land plants (embryophytes): the liverworts, hornworts, and mosses
(BRYOPHYTES) are multicellular, photosynthetic organisms, and some lack vascular tissue. they absorb water and nutrients from the air through their surface -leaves
ex. moss
(TRACHEOPHYTES) possess vascular tissues in their roots, stems, and leaves. absorb water and nutrients through the plant.
ex. fern, bean, corn, grass, oak, etc.
animals
are a large kingdom with multicellular organisms that ingest their own food
(COELENTERATES) 2 cell layers, a hollow body cavity
ex. hydra and jellyfish
(ANNELIDS) segregated body wall
ex. earthworm and sandworm
(ARTHROPODS) jointed appendages and exoskeleton
ex. crayfish and spider
(CHORDATES) dorsal nerve cord
ex. shark, frog, chicken, snake, cat, human, etc.
TF Monera are the MOST PRIMITIVE
T
common ancestry
this is indicated when most classification systems suggest relationships among organisms
Genus
the first part of the organism’s name (in Latin)
species
the second part of its name (in Latin)
ANIMAL VIRUSES
- viruses enter animal cells by membrane fusion or endocytosis
- viral nucleic acid replicated in the host cell
- proteins synthesized
- new viruses are assembled and released from the cell
the two primary bacteriophages
lytic bacteriophages and temperate bacteriophages:
bacteriophages that replicate through the lytic life cycle are called lytic bacteriophages and are named that because they lyse the host bacterium as a normal part of their life cycle
endocytosis
cellular process in which substances are brought into the cell. the material to be internalized is surrounded by an area of the cell membrane, which then buds off inside the cell to form a vesicle containing the ingested material.
this includes pinocytosis (fluids) and phagocytosis (uses pseudopods for solids)
membrane fusion
pathways are made for both the cell with the membrane and the thing trying to consume it. there are cuts made on each. then they attach and the contents go into the cell consuming. then the cell being consumed becomes part of the cell consuming’s membrane
PLANT VIRUSES
- most RNA viruses
- spread among plants by insect receptors
- spread through the plant via plasmodesmata (which is the cell-to-cell communication process; pores can infect one cell to the next cell, to the next)
- virus; streaked tulip which is harmless
- pepper leaves infected with tobacco mosaic virus cause the leaves to die, and they can’t produce
Retrovirus (RNA Virus)
ex. human immunodeficiency virus (HIV)
- uses REVERSE TRANSCRIPTASE (polymerase; is an enzyme used to generate complementary DNA from an RNA template, a process termed reverse transcription)
- transcribe RNA genome into DNA intermediate
- becomes integrated into the host DNA
- synthesize copies of viral RNA
viroids
short strands of RNA w no protein coat
prions (misfolded protein)
consists of only protein and causes TRANSMISSIBLE SPONGIFORM ENCEPHALPATHIES (TSEs) “mad cow disease”, brain tissue disappears from losing brain cells
Kingdom Monera
prokaryotic cells, primitive in design (most primitive) do not have membrane-enclosed organelles such as nuclei and mitochondria
Bacterial Shapes
spherical (cocci)
rod-shaped (bacilli)
spiral:
rigid helix (spirilla)
flexible helix, corkscrew (spirochete)
Bacteria Structure
CELL WALLS are composed of peptidoglycan
- which is a polymer consisting of sugars and amino acids that form a mesh-like layer outside the plasma membrane
- some have CAPSULE (an outer layer of polysaccharides that covers the cells of many different bacterial species. they act as a magic cloak, protecting bacteria from toxic compounds and desiccation (drying) and allowing them to adhere to surfaces and escape the immune system of the host) surrounding the cell wall
Bacterial Cell Walls
GRAM-POSITIVE bacteria
- walls are very THICK
- consists mainly of peptidoglycan
- stains dark blue or violet
GRAM-NEGATIVE bacteria
- walls have a thin peptidoglycan layer
- outer membrane (like plasma membrane)
- stains red or pink
prokaryote genes
genetic material consists of:
- 1 circular DNA molecule
- 1 or more PLASMIDS (circular DNA fragments)
ASEXUAL REPRODUCTION
BINARY FISSION - cell divides, forming two new cells
- the organism duplicates its genetic material, then divides into two parts by cytokinesis, and each new organism receives one copy of DNA
BUDDING - bud forms, then it separates from the mother cell
- unequal cytoplasmic division
FRAGMENTATION - walls form inside of the cell and it separates into several cells
- it replicates then divides walls between the two and they develop to fully mature, like a clone of the original
Prokaryotic Nutrition
most are HETEROTROPHS
- obtain energy and carbon from other organisms
some are AUTOTROPHS
- make their own organic molecules from simple raw materials
- photosynthesis: light
- chemosynthesis: sulfur and heat from mid-Atlantic ridges and vents
heterotrophs
CHEMOHETEROTROPHS:
- free-living DECOMPOSERS
- obtain carbon and energy from dead organic matter
ex. E. Coli
PHOTOHETEROTROPHS:
- obtain carbon from other organisms
- photosynthetic pigments trap light energy
ex. Purple and Green non-sulfur bacteria
autotrophs
CHEMOAUTOTROPHES:
- obtain energy by oxidizing inorganic chemicals such as ammonia
ex. Cyanobacterium
PHOTOAUTOTROPHS:
- obtain energy from the sunlight
aerobes and anaerobes
AEROBIC BACTERIA: require oxygen for cellular respiration
FACULTATIVE ANAEROBES: metabolize anaerobically when necessary
OBLIGATE ANAEROBES: only metabolize anaerobically
ecological roles of prokaryotes
essential DECOMPOSERS while recycling things
- carry out photosynthesis
- many are SYMBIOTIC with other organisms
Bacteria and Disease
- pioneers in microbiology
- anton van leeunwenhoek
- Louis pastor
- Robert Koch
- guidelines to demonstrate specific pathogen causes specific disease symptoms
- Heliobacter pylori: type of bacteria that causes infection in the stomach
Pathogenic Bacteria
EXOTOXINS - strong poisons released by pathogenic behavior
ENDOXOTWINS - poisonous components of cell walls, released when bacteria die
Anti Biotic Resistance
many bacteria have become resistant to antibiotics
R FACTORS: (resistance factor) plasmids with genes for antibiotics resistance
Commercial Importance
- some bacteria produce antibiotics
- some bacteria used to produce cheese
- Lactic and bacteria used in yogurt, pickles, olives, and saurkraut
protists
mostly unicellular eukaryotics organisms
sizes of protists
UNICELLULAR ORGANISMS - microcopic
COLONIES - loosely connected groups of cells
COENOCYTES - multicellular masses of cytoplasm
MULTICELLULAR ORGANISMS - composed of many cells
ex. CHLYAMYDOMAS (bitrophic) - unicellular protist with flagella, cell wall, nucleus, chloroplast, and starch granule
Serial Endosymbiosis
hypothesis: MITOCHONDRIA and CHLOROPLASTS arose from symbiotic relationships between larger cells and smaller cells were incorporated and lived within them
MITOCHONDRIA
- probably originated from aerobic bacteria
CHLOROPLASTS
- single primary endosymbiotic event
- in red algae, green algae, and plants
- cyanobacterium incorporated into a cell
- multiple secondary endosymbioses
- in euglenoids, dinoflagellates, diatoms, golgon algae, and brown algae, some have nonfunctional chloroplasts
ciliates
(protists)
- move by hairlike CILIA
MICRONUCLEI (for sexual reproduction)
MACRONUCLEI (for all cell metabolism and growth)
- undergo complex sexual reproduction (CONJUGATION: two ciliates of a compatible mating type form a bridge between their cytoplasms)
have two nuclei
diatoms
(Protists: algae) mostly unicellular with shells containing silica
- major producers in aquatic ecosystems
some are part of floating plankton
some live on rocks and sediments
- move by gliding
decomposers
most fungi are DECOMPOSERS
- break down organic compounds and dead organisms, leaves, garbage, and wastes into simpler nutrients that can be recycled and used by others
Mutualism
a mutualistic relationship between fungi and the roots of plants
- fungus supplies water and nutrient minerals to plants and plant secretes organic compounds needed by fungus
LICHEN
- a symbiotic combination of fungus and photoautotroph (algae or cyanobacterium)
- photoautotroph provides the fungus with organic compounds, shelter, water and minerals
USEFUL FUNGI
fungi are used as foods (mushrooms, morels, truffles)
- in the production of beer, wine, bread (yeasts)
- to produce cheeses and soy sauce
- to make citric acid and other industrial chemicals
research
fungi are model organisms for molecular biology and genetics: yeast Saccharomyces cercariae and other fungi
biological control of insects such as mosquitos that transmit malaria
medications
fungi are used to make medications: penicillin (from penicillium fungi) and other antibiotics
pathogens
fungi are opportunistic pathogens in humans: ringworm, athlete’s foot, candidiasis (yeast infections), histoplasmosis (cave disease)
toxins
some fungi produce MYCOTOXINS: such as AFLATOXINS (toxin and carcinogenic) and cause liver damage and cancer
Fungal plant diseases
fungal hyphae infect plants through stomata
- hyphal branches (HAUSTORIA) penetrate plant cells and obtain nourishment from cytoplasm
includes: wheat, rust, dutch elm disease (native to Asia) (Bark Beetle), chestnut blishut
