Unit 1 Flashcards
Diversity of Living Things
What is Biodiversity?
The variety of life on earth
- the essential interdependence of all living things
What are species?
A group of organisms that can interbreed in nature and produce fertile offspring
What are the 3 species concepts used to identify what a species is?
- the MORPHOLOGICAL species concept
- The BIOLOGICAL species concept
- The PHYLOGENETIC species concept
What is the morphological species concept?
Anything that focuses on body shape, size and other structural features
Advantages: easy to classify + most widely used
Disadvantages: deciding how much of a difference there can be in appearance (how much variation can there be)
What is the biological species concept?
The ability for organisms to interbreed in nature and produce a fertile offspring that can live
Advantages: widely used by scientists
Disadvantages: cannot be applied in all cases
- species can be separated and never get the chance to interbreed
- organisms that reproduce asexually
- species who are fossilized or extinct and are no longer producing
What is the phylogenetic species concept?
the evolutionary relationships among organisms (the history or DNA)
Advantages: can be applied to extinct species and focuses on using DNA analysis
- can be used to find new species
Disadvantages: evolutionary histories are not known for all species
what are keystone species?
A species on which other species in an ecosystem largely depend, and if they were removed, the ecosystem would drastically change.
What is taxonomy?
the branch of biology that names and groups organisms according to their characteristics and evolutionary history
- science of classifying organisms
has 2 purposes:
- to identify organisms
- to represent relationships among them
What is Binomial Nomenclature and how to use it?
Organizing an organisms scientific name into a combination of 2 terms
- Genus name and species
- both terms are italicized and the first letter of the genus is capitalized
what is the genus?
the taxonomic group of a closely related species
name is indicated by similarities in:
- anatomy
- embryology
- evolution
What is the Hierarchical Classification?
the method of classifying organisms in which species are arranged in categories from most general to most specific
What is a rank and taxon?
rank: each of the eight taxonomic categories is known as a rank
taxon: the name of each rank is called a taxon
the 8 taxonomic levels (8 taxa)
1.domain
2. kingdom
3. phylum
4. lass
5. order
6. family
7. genus
8. species
What are the 3 domains?
- Domain archaea
- includes newly discovered cell types
- 1 kingdom: the Archaebacteria - Domain Bacteria
- includes other members of old kingdom Monera
- 1 kingdom: the Eubacteria - Domain Eukarya
- includes all kingdoms composed of organisms made up of eukaryotic cells
- 4 kingdoms: – Protista, Fungi, Animalia, Plantae
What are the kingdoms of life?
organisms in each kingdom are similar in their cellular structure, methods of obtaining nutrients, and metabolism
- Archaebacteria
- Eubacteria
- Protista
- Fungi
- Plantae
- Animalia
What are prokaryotic and eukaryotic cells
Prokaryotic: a smaller, simple type of cell that does not have a membrane-bound nucleus
- Bacteria and archaea are prokaryotes
Eukaryotic: a larger, compex type of cell that does have a membrane bound nucleus
- Protista, plants, fungi, and animals are eukaryotes
Explain the factors of a virus
- Viruses are functionally dependent on the interval workings of cells
- can be found in both eukaryotic and prokaryotic cells
- not able to live independently outside of cells
- they must invade cells are use host cells machinery for survival and reproduction
- viruses are found everywhere
- consist of a core of nucleic acid (either DNA or RNA) and a protein coat (capsid)
- not considered “living organisms”
- they have one sign of life: the ability to reproduce at a fast rate inside a host cell.
viruses + bacteriophages?
bacteriophages: viruses that attack bacteria
both invade cellas and use the host cell’s machinery to synthesize more of their own macromolecules
the virus undergoes replication within a host cell
once inside the host they will either go into a lytic cycle or lysogenic cycle.
what is the lytic cycle?
the replication procces in viruses that occurs inside the host cell and makes new viruses
- destroys the host cell furing reproduction
- you get immediate disease symptoms
has 5 parts
1. attachment (protiens on surface of virus bind to protien on the surface of the host cells membrane)
2. Insertion (the virus injects its genetic material (RNA/DNA) into the host cell
3. Host DNA disrupted
4. replication of viral parts and assembly (the host makes more viral DNA or RNA protiens and new viral particles are assembled)
5. Lysis/release (the host cell breaks open and releases new viral particles)
Lysogenic Cycle?
the replication process in viruses where the viral dna enters the host cell without killing the host
incorporates viral DNA into the hosts chromosome
the virus may stay dormant until it activates and can produce more viruses.
- dna becomes part of the host cells chromosome
- cell division ( provirus replicates with hosts chromosones)
- provirus leaves the hosts chromosome.
What are the 4 shapes that classify a virus? give description
- Helical
- rod shaped
- coiled to helix shape
- may look like a hollow tube
- forms a capsid
- protein subunits stacked around nucleic acid - Icosahedral
- protien subunits form geometric rectangular patterns
- like a soccer ball - Enveloped virus
- capsid is enclosed in phospholipids (fatty acids) or proteins taken from host cell - complex virus
- includes many shapes in one
- common shape for bacteriophages
- has a head and tail
Retrovirus + provirus?
retrovirus: single-stranded RNA viruses that convert thier RNA to the hosts DNA so viral DNA can join with host DNA
- a virus that uses RNA as its genetic material
Provirus: after a DNA virus has been incorprorated into a host cells chromosome
5 transmissions of viruses
- Respiratory Transmission
- Fecal-Oral transmission
- blood-borne transmission
- sexual transmission
- animal or insect vectors
what do Bacteria and archaea have in common
- both are domains within prokaryotes
- living things without a nucleus
what makes archaes so unique
- they can survive in extreme : tempreatures, pH, darkness, gasses, habitats
(lipids help in hot temp and fatty substances help in cold temp) - do not use oxygen for energy (anaerobic) (live in oxygen free envionrments)
- instead gather it from inogranic molecules or light
- use carbon dioxide, nitrogen gas, hydrogen sulfide as energy
- vayr similar to bacteria biochemically but are genetically different
—- RNA chemical differences
—- chemical composition
—- cell membranes - are methogens (produce methane (waste)
what are the 3 major groups of archaea
- thermophiles (heat lovers)
- acidophiles (acid-loving)
- halophiles (salt-lover)
What is the kingdom eubacteria?
- organisms commonly refered to as “bacteria”
- need oxygen
- classified by shape, cell wall, and energy source
What are the 3 bacterial shapes?
- COCCUS/COCCI
- spherical shape
- caused by tooth decay
- resist drying - BACILLUS.BACILLI
- rod-shape
- caused by food poisonsing
- good at absorbing nutrients - SPIRILLUS/SPIRILLUM
- spiral shape
- caused by syphillus (sexually transmitted infection)
- moves through fluids with less resistance
Bacterial shape 3 prefixes
- DIPLO-
- arranged in pairs - STAPHYLO-
- arrange in clusters - STREPTO-
- arranged in chain
how and 2 indicators for cell wall structure?
using staining techniques to fin the difference’s in amino acids and sugar molecules in cell walls.
- gram-positive: think protein outer layer (purple)
- Gram negative: thin protein outer layer (pink)
4 major Energy sources?
- HETEROTROPHS
- eats organic molecules from envionrment
- eats other organisms - PHOTOAUTOTROPH
- uses sunlight to make energy - PHOTOGETROTROPH
- both 1 and 2 - CHEMOHETEROTROPHS
- uses energy released through chemical reactions
What is the asexual reproduction of bacteria?
Binary fission
- as a cell grows, it makes a copy of its chromosome
- once it reaches a certain size the cell separates and creates a partition (septum) between the 2 cells
- the cell splits into 2 small identical cells
- produced within 20 min
Name and explain the 3 sexual reproductions of bacteria
- conjugation
- producing cells with new genetic codes
- to better adapt to changing conditions
- a pilus connects the cells together and transfers the dna into the other - Transformation
- takes up pieces of DNA from environment (nearby bacteria) - Transduction
- bacteriophages infect bacteria
- cary bacterial genes from one cell and inject them into another