Unit 1 Diversity Of Living Things Flashcards
How many species have been identified vs how many are there?
There are over 1.7 million living things identified, but there may be 15 million alive
Why are so many species unidentified?
Many live in the ground or the water, and many are very small
Of all the species that have ever lived on earth, _____% are living today
0.1%
Taxonomy
The branch of biology that identifies, groups, and names organisms
Classification
The organizing of information into a useable, workable, order that shows the relationship between organisms
How is taxonomy useful?
- helps prevent confusion among scientists
- helps to show organisms are related
- can be used to reconstruct phylogenies (evolutionary histories) of an organism or group
- allows for accurate naming
- applications - doctors identify infectious disease before treatment so correct antibiotics can be used, farmers separate weeds from crops
History of taxonomy
- always trying to classify
- Aristotle placed objects into two groups, plants and animals, but only 1000 organisms had been identified
- 18 century Swedish naturalist Carolus Linnaeus simplified the system
Linnaeus System
(Domain) Kingdom Phylum Class Order Family Genus Species
7 level system of divisions
Rank
A single hierarchical level in the Linnaeus system
Taxon (pl taxa)
Classification of an organism at a rank
Biological species concept
A group of organisms so similar that they can interbreed and produce fertile offspring in natural conditions
Morphological species concept
Concept focuses on morphology, body shape, size, and other structural features
Phylogenetic species concept
Examines he evolutionary history of organisms
Binomial nomenclature
A two name system for writing scientific names
Requirements of binomial nomenclature
Genus name is written first (capitalized)
Species name is written second (uncapitalized)
Both words are italicized if typed, underlined if handwritten
Why do we use binomial nomenclature?
Common names can give the wrong impression
People in different countries have different names for the same organism
Biodiversity
The number and variety of species and ecosystems on earth
Number of Domains and what are they?
3
Bacteria
Archaea
Eukarya
What type of cells are bacteria?
Prokaryotes
What type of cells are archaea?
Prokaryotes
What type of cells are eukarya?
Eukaryotes
Kingdom within domain bacteria?
Bacteria “eubacteria”
Kingdom within domain archaea
Archaea bacteria
Kingdoms within domain eukarya
Animalia, plantae, Protista, fungi
Bacteria
- unicellular micro organisms
- variety of different shapes
- can be found in almost every ecosystem
- some are pathogenic and cause disease
- found all over the body but are mostly harmless
- important to nutrient cycles and decomposition
Characteristics of Bacteria - Morphology
- unicellular
- no nuclear membrane or membrane bound organelles
- tiny 1-10mm
- have only one circular chromosome
- have a cell wall (usually)
Shapes of bacteria
Bacillus Coccus Spirillios Vibrio Spirchaetus
Bacillus
Rod shaped
Coccus
Sphere
Spirillios
Spiral
Vibrio
Boomerang shaped
Spriochaetus
Tight coils shape
Prefixes for bacteria
Strepto
Staphylo
Diplo
Staphylo
Grape like cluster
Diplo
2 bacteria
Characteristics of Bacteria - Netabolism
- autotrophs
- heterotrophs
Autotrophs
Make own food (undergo photosynthesis)
Kingdom egih
Example Cyanobacteria
Heterotrophs
Obtain energy from eating other organisms
Example e. Coli
Pilus
A protein projection from a cell that is used to transfer DNA from one bacteria to another
Fimbrae
Sticky projections that allow bacteria to stick to surfaces
Plasmid DNA
Contains a few genes in the cell
Capsule
Part of the bacteria cell wall
What contains bacteria genes?
Singular circular DNA chromosome
Flagella
Allows for mobility of bacteria. May be one or many
Strepto
Chain of bacteria
Ribosomes
Makes/assembles proteins
What sets kingdom archaea apart?
- lack peptidoglycan in the cell wall
- unaffected by antibiotics
- different lipids in membrane
- different gene sequences
- different types of ribosomes
- do not cause disease
- perform methanogenesis
Extremophile
Archaea bacteria that can live in extremely harsh environments
Types of extremophiles
Thermophile
Acidophile
Halophile
Thermophile
Archaea bacteria
Love heat
Acidophile
Archaea bacteria
Love low pH
Halophile
Love salt
Kingdom Bacteria characteristics
- the larger of the two prokaryotic kingdoms
- cell wall has peptidoglycan
- can cause disease
- live nearly everywhere
Gram staining
A method to classify kingdom bacteria based on their cell walls
Gram positive
- turns purple
- thick cell wall, no outer membrane
- less common
- killed by antibiotics (ex penicillin)
Gram negative
- turns pink
- thin cell wall with outer membrane
- unaffected by antibiotics because they can’t get through the outer membrane
- more common
How do antibiotics work?
Punching holes in the cell wall of bacteria to allow the body’s natural defended to be effective or prevent the bacteria from reproducing
What are antibiotics used to treat?
Bacterial diseases
Binary fission
How bacteria reproduce
Cell duplicates it’s DNA and divides so half the DNA is in each cell
Steps in binary fission
- DNA replication
- Cell membrane and cell wall synthesis
- Cell separation
What 3 ways do bacteria reproduce?
Binary fission
Spore formation
Conjugation
Endospores
- structures created within certain genera of bacteria which enable these bacteria to survive harsh conditions
- can lay dormant for centuries
- resistant to heat, acids, low nutrient levels, desiccation and radiation
How do endospores form?
DNA is duplicated (spore forms inside original cell), cell breaks open, spore is released and blows away, begins growing when suitable conditions return
How long does binary fission take?
20 minutes in ideal conditions
After binary fission, both daughter cells are _____________
Identical
Conjugation
The transfer of bacterial DNA directly from one bacterium to another via a pilus
How do modern biologists classify bacteria with cell walls? (A method other than gram staining)
DNA comparisons
Advantages of being a mesophile
A greater chance for survival due to the abundance of places to live
Methanogenesis
Archaea bacteria undergo methanogenesis, which is a biological process that produces methane as a by-product
Why is raising cows dangerous to the environment?
The archaea bacteria in the guys of cows undergo methanogenesis as a by product, which is a greenhouse gas and is harmful to the environment
Virus characteristics
- poisonous
- infectious, non living, non cellular particles
- contain no cytoplasm
- cannot grow or reproduce on own
- don’t produce or use energy
- do not create waste
- antibiotics are ineffective
What is a virus?
A package of genetic instructions that can enter and take control of cells and the cell eventually makes copies of the virus
How do we classify viruses?
By virus shape and method of viral reproduction
How big are viruses?
Less than 0.1 micrometers in diameter
Hundreds of thousands can fit inside a human cell
Basic structure of a virus
Genetic material (RNA or DNA)
Capsid
Either naked or enveloped
Capsid
A protein coat that surrounds and protects the genetic material
Difference between naked and enveloped virons
Enveloped are when the capsid is surrounded by a lipid bilayer and naked are not
Virus shapes
Helical
Polyhedral
Complex
Helical virus shape
Rod like with capsize proteins winding around core like a spiral
Polyhedral virus shape
Many sides
Many have 20 sides and 12 corners
Complex virus shape
A polyhedral capsid attached to a helical tail
The tail is made of protein which aids in binding to host cell
Parts of a bacteriophage
Head - capsid, genetic material
Tail - sheath (neck), tail fibres
Bacteriophage
A virus that attacks bacteria
Example of RNA virus
HIV
Flu
Rabies
Example of DNA virus
Chickenpox
Herpes
Hepatitis
Difference between RNA and DNA
RNA is single stranded and has a higher mutation rate whereas DNA is double stranded and is more stable. DNA is also affected by vaccines
Methods of viral reproduction
Lytic cycle
Lysogenic cycle
Steps of Lytic cycle
Attachment, injection of genetic material, synthesis, assembly, lysis
Steps of lysogenic cycle
Attachment, injection, integration into DNA, replication of host cell, trigger, synthesis, assembly, lysis
Provirus
Any virus that has been incorporated into a host cell
Retrovirus
An RNA virus. The host cell copies the RNA virus into DNA, then it is a provirus
3 Ways a Virus Enters a Cell
Punches a hole and injects DNA
encyotisis - if cell recognizes virus, it will engulf it and attempt to destroy it
Through tiny tears in plant cell wall
Vector
Carries a virus from one host to another
Can be an animal, insect, water, human, or air
Length of time for symptoms to appear for lytic cycle and lysogenic cycle viruses
Lytic cycle - quickly
Lysogenic cycle - a long time , months or years
The majority of bacteria are ___________ (dangerous or harmless)
Harmless
Antigen
Anything that initiates an immune response
Cells and viruses have markers on them that allow the body’s immune system to identify them
Active immunity
When the body produces its own antibodies to fight off infection
How does the body acquire active immunity?
Get infection, antibodies are produced, and body fends off illness, so the next time it can produce antibodies immediately and body will not get sick
Get a vaccine so the body gets practice making antibodies so if ever exposed you can make antibodies immediately
Vaccine
Contains dead or weakened particles of a disease causing pathogen, which is given to the body so it can have practice making antibodies
The theory of endosymbiosis
Explains how eukaryotic cells evolved from the symbiotic relationship between two or more prokaryotic cells
What happens in endosymbiosis?
One cell engulfs another cell but the engulfed cell survives and becomes an internal part of the larger cell
Endosymbiant
A cell that is engulfed by another cell through endosymbiosis
Host cell (endosymbiosis)
A cell that engulfs another cell in endosymbiosis
Proof of endosymbiosis
Chloroplast and mitochondrial have own DNA, have ribosomes, undergo binary fission, and have membranes similar to those of living prokaryotes
Who created the theory of endosymbiosis?
Lynn margulis in 1967, but was ridiculed
Characteristics of protists
- mostly single celled
- all eukaryotic
- either heterotrophic or autotrophic
- some have cell walls, some are motile
- most live in water, some live in moist soil, some live in human body
What is another name for the protist group?
The kitchen sink
How are protists characterized?
How they move and how they get their nutrients
What are the 3 main groups of protists?
Animal like protists
Plant like protists
Fungi like protists
What is another name for animal like protists?
Protozoans, meaning first animals
How do animal like protists obtain nutrition?
They are heterotrophs
How are animal like protists classified?
Based on their method of movement
What are the phylums that are part of the animal like protists
Phylum cercozoa
Phylum ciliophora
Phylum harbm
Phylum sporozoan
Characteristics of phylum cercozoa
- No cell wall so can change shape
- produce pseudopods for movement and to engulf their prey
Example of phylum cercozoa
Amoeba
-intestinal amoebas in humans cause chronic diarrhea
Characteristics of phylum ciliophora
- have cilia that beat together in rhythm for movement and are used to capture food particles
- often have two nucleuses
Example of phylum of phylum ciliophora
Paramecium
Characteristics of phylum zoomastigina
- have one or more flagella (whip like tail)
- some are parasites while others are mutualistic
Example of phylum zoomastigina
Beaver fever
Characteristics of phylum sporozoans
- produce spores
- passive movement
- parasites
Examples of phylum sporozoan
Plasmodium vivax which causes one type of malaria in humans
Features of plant like protists
- autotrophic
- contain pigments (ex chloroplasts)
Types of plant like protists
- diatoms (chrysophytes)
- dinoflagellates (pyrophytes)
- euglenoids
- algae
Characteristics of diatoms
- most abundant algae in oceans
- also known as phytoplankton
- rigid cell walls contain silica
- main producers of aquatic food webs
Silica
Sand and glass
Pseudopod
False foot
Extension of cytoplasm to catch prey
Characteristics of dinoflagellates
- photosynthetic
- mostly marine
- stiff protective cellulose coat
- have two distinctive flagella that create a spinning or twirling motion
- contain toxins that build up in the shellfish that eat them
- phosphorescent form red tides with photosynthetic pigment
Characteristics of euglenoids
- freshwater
- have chloroplasts
- one large anterior whip-like flagella
- can be autotrophic in sunlight, or heterotrophic when sun is gone
Characteristics of algae
- can be different colours
- many groups
- some debate where algae belongs (protist or plant)
- can be single celled or multicellular
Features of fungi like protists
- have a cell wall (different from fungi kingdom)
- heterotrophs
- glide from place to place
- cellulose in cell walls like plants
- have characteristics of fungi, Protozoa, and plants
- absorb nutrients and help the decomposition cycle
Types of fungi like protists
Water moulds
Slime moulds
Characteristics and example of water moulds
- saprotrophs or parasites
- resemble fungi
- cause of potato famine
- ex downy mildew
Slime moulds characteristics and example
- break down, direct nutrients and cycle through ecosystem
- visible to naked eye as a tiny slug like organism
- ex dog vomit slime mould
Ecosystem diversity
Variety of ecosystems in a biosphere
Species diversity
The variety and abundance of species in a given area
Genetic diversity
The variety of heritable characteristics in a population of interbreeding individuals
