Lecture 8 Study Guide Flashcards
- What type of microscope allows researchers to observe organelles?
electron microscope
- List three advantages of light microscopy over electron microscopy.
- labeling individual cellular molecules or structures w/ fluorescent markers has made it possible to see such a structure w/ increasing detail
- both confocal and deconvolution microscopy have produced sharper images of 3-D tissues and cells
- a group of new techniques and labeling molecules developed in recent years has allowed researchers to “break” the resolution barrier and distinguish sub cellular structures even as small as 10-20 nm across
- State the main application of cell fractionation.
to study the internal structure of cells and each component’s function
- List 4 features found in all cells on the plant.
- plasma membrane
- cytoplasm
- chromosomes
- ribosomes
State the method by which prokaryote cells
binary fission
Define eukaryote and state the method of cell division.
eukaryote: a multicellular organism with a nucleus and membrane bound organelles
method of cell division: mitosis
Outline the restrictions placed on the maximum size of a cell.
the ratio between surface area and volume
functions of eukaryotic organelles (mitochondria, plasma membrane, smooth ER, cytoskeleton, nucleus, nucleolus, Golgi apparatus, rough ER, ribosomes, chloroplasts, cell wall)
mitochondria: produce energy (ATP)
plasma membrane: act as a selective barrier
smooth ER: synthesis of lipids
cytoskeleton: determines the shape of the cell
nucleus: contains genetic info
nucleolus: rewrite ribosomal RNA and combine it w proteins
Golgi apparatus: modifying, sorting, and packaging of proteins for secretion
Rough ER & ribosomes: protein synthesis
chloroplasts: convert light energy into sugars for the cell
cell wall: protect the cell
Define phylogeny.
branch of biology that studies the evolution of organisms
Describe the relationship between binomial nomenclature and the Linnaean hierarchical classification system.
the binomial classification gives a organisms their species names (first part is the genus they are apart of and second part is unique to that organism). The Linnean classification starts with species then moves downward (species-genus-family-order-class-phylum-kingdom-domain)
In a phylogenetic tree, a dichotomy (aka branch point) represents what?
each branch point represents the common ancestor of the 2 evolutionary lineages
Briefly describe the defining traits of the three domains of life.
The 3 domains are made up of bacteria, archaea, and eukaryotes. Bacteria and archaea are both prokaryotes (unicellular). However, archaea and eukaryotes are more like each other than either is with bacteria.
Define horizontal gene transfer and list three mechanisms that may allow it to occur.
horizontal gene transfer: a process in which genes are transferred from one genome to another
Mechanisms: exchange of transposable elements and plasmids, viral infections, or fusions of organisms
Elaborate on the horizontal transfer of modern day mitochondria and chloroplasts.
between the archaea and eukaryotes, mitochondria and chloroplasts were transferred over to plants form archaea
State the name of the polymer found in prokaryotic cell walls. How does it differ from cellulose?
peptidoglycan: a polymer composed of modified sugars cross-linked by short polypeptides
State the difference in the location of the peptidoglycan and the plasma membrane in gram-positive vs gram-negative bacteria. How do these two types of bacteria respond differently to antibiotics, in general.
gram-positive: have relatively simple walls composed of a thick layer of peptidoglycan
gram-negative: hace less peptidoglycan and are structurally more complex w an outer membrane that contains lipopolysaccharides
gram-negative is more resistant to antibiotics
Define the following items that may be found in prokaryotes: Capsule Endospores Fimbrae Pili Positive chemotaxis Flagellum Amount and organization of DNA Plasmids
Capsule: sticky layer of polysaccharides or protein that surrounds the cells
Endospores: resistant cells
Fimbriae: hairlike appendages’
Pili: appendages that pull two cells together prior to DNA transfer
Positive Chemotaxis: move away from toxic chemicals
Flagellum: allows cells to move
Amount and Organization of DNA: Prokaryotes are structurally simpler and have less DNA than eukaryotes
Plasmids: small rings of independent DNA replicating molecules
Compare and contrast the process of cell division in prokaryotes and eukaryotes.
prokaryotes undergo binary fission (asexual). eukaryotes undergo mitosis and meiosis
Describe two behaviors in eukaryotes made possible by the cytoskeleton.
enables eukaryotic cells to asymmetric forms and change shape as needed
Define the following terms: Photoautotroph Chemoautotroph Heterotroph Saprotroph Endosymbiosis Secondary endosymbiosis
Photoautotroph: contain chloroplasts, produce own food and energy
Heterotrophs: absorb and ingest food/energy
Chemoautotroph: obtain energy through oxidation
Saprotroph: an organism that feeds on or derives nourishment from decaying organic matter
Endosymbiosis: a relation between two species in which one organism lives inside the cell or cells of another organism
Secondary Endosymbiosis: ingested in food vacuoles of heterotrophic eukaryotes
Outline the three main tenets of cell theory.
- cells are the most basic fundamental units of life that can do all the functions of life
- all organisms are composed of cells
- all cells come from pre-existing cells
List four molecules that were present in the atmosphere of the early Earth
- water vapor, Hydrogen gas, methane, ammonia
Compare 4 features shared between prokaryote cells and the mitochondria and chloroplast organelles.
- cell membranes
- genetic material
- ribosomes
- metabolism
