Flashcards in Ch. 25, 26, 27 Deck (119):
The scientific discipline concerned with classifying and naming organisms
What are the taxonomic groups from broad to narrow?
Domain, kingdom, phylum, class, order family genus, species
Similarity due to shared ancestry
Similarity due to convergent evolution
When similar environmental pressures and natural selection produce similar adaptations in organisms from different evolutionary lineages
Analogous structures or molecular sequences that evolved independently
Grouping that consists of an ancestral species and some but not all of the descendants
Grouping that includes distantly related species but does not include their most recent common ancestor
Uses constant rates of evolution in some genes to estimate the absolute time of evolutionary change
Genes found in a single copy in the genome. Are homologous between species.
The movement of genes from one genome to another
Horizontal gene transfer
When did earth form
4.6 billion years ago
What was the first genetic material?
What kind of species is the fossil record biased in favor of?
Species that existed for a long time, were abundant and widespread, and had hard parts
How are the absolute ages of fossils determined?
By radiometric dating
What are the three eras that the Phanerozoic era is divided into?
Paleozoic, Mesozoic, Cenozoic
What is the name of the oldest known fossils?
Rocks formed by the accumulation of sedimentary layers on bacterial mats
Theory that proposes that mitochondria and plastids (chloroplasts & related organelles) were formerly small prokaryotes living within larger host cells
The endosymbiont theory
What causes extinction?
Changes in a species' environment
The result of disruptive global environmental changes
The sudden appearance of fossils resembling modern animal phyla in the Cambrian period
When was the Cambrian period?
535 million years ago
What are some effects that formation of Pangaea had?
Deepening of ocean basins, reduction in the shallow water habitat, a colder and drier climate inland
When was Pangaea formed?
250 million years ago
What is the most important feature of all prokaryotic cells? Why?
Their cell wall. It maintains cell shape, protects the cell, and prevents it from bursting in a hypotonic environment
Bacteria cell walls contain ____, a network of sugar polymers cross-linked by polypeptides
Allow prokaryotes to exchange DNA
Metabolic cooperation occurs between different prokaryotic species in surface-coating colonies
What are the four major modes of nutrition that energy and carbon sources combine to give?
Photoautotrophy, chemoautotrophy, photoheterotrophy, chemoheterotrophy
Name three factors that contribute to genetic diversity in prokaryotes
Rapid reproduction, mutation, genetic recombination
The movement of genes between bacteria by bacteriophages (viruses that infect bacteria)
How can some bacteria survive antibiotics?
Some bacteria have R plasmids which carry genes for antibiotic resistance
Obtain energy from light
Obtain energy from chemicals
Require CO2 as a carbon source
Require an organic nutrient (like carbon) to make organic compounds
What are three things that prokaryotes can sometimes increase for plant growth?
The availability of nitrogen, phosphorus, and potassium
What are three factors contributing to extinction?
Toxic conditions, global warming, intense volcanos
How are RNA molecules produced?
Spontaneously from simple molecules
Time required for half the parent to decay
How long ago was Earth formed?
4.6 billion years ago
Rapid evolution of diversely adapted species from a common ancestor
Groups that share an immediate common ancestor
What is the purpose of cladistics?
To group organisms by common descent
Character that originated in an ancestor of the taxon
Shared ancestral character
Evolutionary novelty unique to a particular clade
Shared derived character
What was the first cell?
Are prokaryotes multicellular or unicellular?
What makes up the cell walls of eukaryotes?
Cellulose or chitin
What are the three main parts that bacterial flagella are composed of?
Motor, hook, and filament
What are three key functions of prokaryotic reproduction?
2. Reproduce by binary fusion
3. Short generation time
What are three factors that contribute to genetic diversity?
1. Rapid reproduction
3. Genetic recombination
What covers many prokaryotes?
What is the purpose of R plasmids?
Carry genes for antibiotic resistance
One bacterial cell attaches a pilus to the other bacterial cell in order to transfer DNA
//when genetic material is being transferred between prokaryotic cells
What are the two parts in the binomial format in naming an organism?
Genus and epithet
Group that consists of an ancestral species and all of its descendants
What does branch length represent on a phylogenetic tree?
Level of evolutionary change or times which particular events occurred
What are the two types of homologous genes?
Orthologous and paralogous
What are the three domains of life?
Eukarya, archaea, bacteria
A group which includes an ancestral species and all of its descendants
Consists of distantly related species but does not include the most recent common ancestor
Where lineages diverge on a phylogenetic tree
Bacteria that have a large amount of peptidoglycan on the cell wall
Gram positive bacteria
Bacteria that have less peptidoglycan. Have an outer membrane that contains lipopolysaccharides
Gram negative bacteria
What is a way that mutualistic bacteria benefits humans?
Digests food we cannot break down; signals for building of network of intestinal blood vessels; induce human cells to produce antimicrobial compounds
Released when the bacteria dies and the cell wall breaks down
Proteins released by bacteria that causes illness and disease in humans
One species benefits but the other is neither harmed nor gains any benefit in the relationship
Is cyanobacteria gram positive or gram negative?
What is the energy source of photo heterotrophs?
A time scale dividing Earth's history into four eons and several other subdivisions
In which eon did single celled eukaryotes appear on earth?
What caused the single continent Pangea to become the 7 continents of present day?
What were the two most recognized of the "Big Five" mass extinction events?
Permian and Cretaceous
Deep sea vents that release warm, high pH water
What are the four stages that had to happen for very simple cells to be produced in early earth?
1. Abiotic synthesis of small organic molecules
2. Joining these small molecules to make macromolecules
3. Packaging molecules into protocells
4. Origin of self-replicating molecules (making inheritance possible)
RNA catalysts that can also aid in duplicating RNA
True or false: in water lipids and other organic molecules can spontaneously form vesicles with a lipid bilayer
What group of animals do mammals belong to?
Assumes that the tree that requires the fewest evolutionary events (appearances of shared derived characters) is the most likely
The ability to move toward or away from a stimulus
In a heterogeneous environment, many bacteria exhibit ___
Some species of bacteria have smaller rings of DNA called ___
Movement of genes among individuals from different species
Horizontal gene transfer
Some archaea live in extreme environments and are called ___
Live in highly saline environments
Thrive in hot environments
An ecological relationship in which two species live in close contact: a larger host and a smaller symbiont
One organism benefits while neither harming or helping the other
Both symbiotic organisms benefit
The emergence of terrestrial vertebrates, the impact of mass extinctions, and the origin of flight in birds are examples of what kind of changes?
The evolutionary history of a species or group of related species
What do small organic molecules do when they are concentrated on hot sand, clay or rock?
What are two key properties of life that may have appeared together in protocells?
Replication and metabolism
How may have protocells formed?
From fluid-filled vesicles with a membrane-like structure
What do ribosomes do?
Catalyze reactions and can make complementary copies of short stretches of RNA
T or F: natural selection has produced self-replicating RNA molecules
Give an example of phylogeny
Shows that legless lizards and snakes evolved from different lineages of legged lizards
Classifies organisms and determines their evolutionary relationships
The two-part scientific name of a species
List five parts of a phylogenetic tree
1. Branch point
2. Sister taxa
3. Rooted tree
4. Basal taxon
Represents divergence of two species
Groups that share immediate common ancestor
Includes branch to represent last common ancestor of all taxa in the tree
Diverges early in history of a group; originates near common ancestor of group
Branch from which more than two groups emerge
What can phylogenetic trees not show?
When species evolved or how much change occurred in a lineage
Give example of practical use of phylogeny
To identify the species of whale from which whale meat originated
What makes Utah's Great Salt Lake a pink color?
What is the salt concentration that Utah's Great Salt Lake can reach?
True or false: prokaryotes can only survive in certain conditions
False: prokaryotes can thrive almost anywhere, even in places that are too acidic, salty, cold, or hot for most other organisms
What are the two domains that prokaryotes are divided into?
Bacteria and archaea
What are the three most common shapes of prokaryotes?
Spheres (cocci), rods (bacilli), and spirals
What do bacterial cell walls contain?
Peptidoglycan-a network of sugar polymers cross-linked by polypeptides
Archaea contain ___ and ____ but lack ____
Polysaccharides and proteins; lack peptidoglycan
Simpler walls, lots of peptidoglycan