LS 1 Mastering Bio – Flashcards
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Which is the best definition of adaptive radiation
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An adaptive radiation occurs when a single lineage produces many ecologically diverse descendant species in a relatively short period of time
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How can mass extinction events be distinguished from background extinctions
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A mass extinction occurs when at least 60 percent of species are wiped out within 1 million years
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Why do mass extinctions wipe out species more or less randomly
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They are caused by exceptionally harsh, short-term conditions
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Why is bipedalism considered a synapomorphy for hominins (the group that includes humans)
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Hominins are the only mammal group to walk on two legs.
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Which structures are homologous
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oak leaf and maple leaf
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How might paleontologists be misled by their observations of fossils
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They typically only find species that were widespread and/or present on the Earth for long periods of time
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How do lizard species on mainland California compare in diversity to those found on islands
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Due to more open ecological opportunities on a given island, greater differences occur between island species
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Which is strong evidence supporting the impact hypothesis for the extinction of the dinosaurs
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Extremely high quantities of iridium in rocks that formed around 65 million years ago
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What is the best evidence that all life evolved from prokaryotic rather than eukaryotic ancestors
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The oldest fossil form of life known is prokaryotic.
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Cyanobacteria are thought to be the first organisms to evolve
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oxygenic photosynthesis
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Aerobic respiration is more efficient than anaerobic respiration because of what property of oxygen
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It is highly electronegative
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Members of which bacterial phylum share a unique morphology
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Spirochaetes
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On the figure, where would you mark the origin of the trait of "oxygenic photosynthesis"
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At the base of cyanobacteria
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Unlike plant cell walls that contain cellulose, bacterial cell walls are composed of
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peptidoglycan
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Which character separates bacteria from archaea
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Bacteria have peptidoglycan in their cell wall.
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What method would you use to best identify the diversity of bacterial and archaeal species in the soil present on your campus
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Metagenomics
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What is distinctive about the chlorophylls found in different photosynthetic bacteria
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their absorption spectra
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What is a potential ill effect of adding iron to ocean waters
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An algal bloom that causes a massive loss of oxygen creating a dead zone
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Primary production by photosynthetic protists is considered "primary" because
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these protists produce chemical energy by fixing CO2
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When a mosquito infected with Plasmodium first bites a human, the Plasmodium
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cells infect the human liver cells
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Why does iron fertilization of open oceans increase phytoplankton densities
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The growth of phytoplankton is often limited by iron availability in the open oceans
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Why can dinoflagellate blooms be harmful to humans
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People can get paralytic shellfish poisoning during dinoflagellate blooms
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Which of the following eukaryotic lineages contains species that all lack functioning mitochondria
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Excavata
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According to the endosymbiosis theory, how many membranes should a mitochondrion have
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Two
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Chloroplasts arose via
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endosymbiosis of cyanobacteria
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In a rapidly changing environment, protists tend to reproduce
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via sexual reproduction
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What synapomorphy defines the Eukarya
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nuclear envelope
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Why are protists considered paraphyletic
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They include some but not all descendants of their most recent common ancestor
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Where on the phylogenetic tree should the origin of macronucleus/micronucleus structure appear
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At the base of ciliates
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Where on the phylogenetic tree should the origin of chloroplasts appear
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At the base of Plantae
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What impact will the loss of land plants have on the soil
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Decrease soil stability
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The major function of the medicinal compounds in plants is to
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defend the plant against herbivores
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Plants synthesize toxic compounds to repel insects, deer, or other herbivores. Isolating these compounds is important in terms of their value to the development of new
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pharmaceuticals
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Angiosperms are most closely related to
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gymnosperms
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Which of these was the dominant plant group at the time that dinosaurs were the dominant animals
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gymnosperms
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Plants evolved from green algae approximately _____ million years ago
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475
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_____ are an example of seedless vascular plants
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Ferns
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The living plants that are most similar to the first plants to bear gametangia are the
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bryophytes
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What group was likely ancestral to land plants
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multicellular green algae found in freshwater habitats
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Vessel elements are more efficient at transporting water than tracheids because
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vessel elements are wide
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In the horsetail figure, the image on the right is which stage
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Sporophyte
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What trait gives seeds an advantage over spores
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Contain nutrients
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Cuticle, stomata, and vascular tissue are all key adaptations enabling land plants to
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colonize land
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What does the directed-pollination hypothesis suggest
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Natural selection has favored flower traits (scent, shape, color) that attract pollinating animals
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On the phylogenetic tree, where should the origin of microphylls be placed
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At the base of Lycophyta
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Which of the following groups is definitely monophyletic
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seed plants
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What impact would the spraying of fungicide have on soil-dwelling organisms
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Plant and animal diversity would decrease due to reduced amounts of available carbon and nitrogen.
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Why are fungi so important to the carbon cycle
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Fungi accelerate the carbon cycle by breaking down wood and thus freeing up carbon atoms
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As a group, fungi are
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decomposers
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Fungi release digestive enzymes into their
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surroundings
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Basidia produce spores by a process known as
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meiosis
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Which of the following is NOT a reproductive structure in fungi
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Mycelia
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Why is it more difficult to treat fungal infections than bacterial infections in humans
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Fungal and animal cells and proteins are similar. Thus, drugs that disrupt fungal cell or protein function may also disrupt human cell or protein function.
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Fungal mycelia
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have a large surface area composed of branching hyphae
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Mushrooms, brackets, and puffballs are examples of structures used for
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reproduction
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The fundamental reproductive cell produced by fungi is the
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spore
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Experiments with isotopes used as tracers showed that some fungi
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obtain sugars from plants in exchange for phosphorus, nitrogen, and other soil nutrients
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Fungal digestion
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is extracellular, meaning that it takes place outside the organism
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What is the symbiotic relationship that characterizes arbuscular mycorrhizal fungi (AMF)
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AMF provide key nutrients to tree, grass, and shrub roots in exchange for sugar
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The mycelial growth habit leads to a body with a high surface-area-to-volume ratio. Why is this important?
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Mycelia have a large surface area for absorption
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Why is it logical that most fungi don't have lignin or cellulose in their cell walls
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Fungi produce enzymes that degrade cellulose and lignin
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How do fungi acquire nutrients
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Fungi absorb nutrients from other organisms, living or dead
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What would occur to plants in an area if animals were excluded
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Increased plant abundance
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The number of phyla of animals currently recognized by biologists is approximately
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30 to 35
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In your body, the inside "tube" within a "tube" is derived from the
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endoderm
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The expression of the gene dpp in the bilateral form in a variety of animals is evidence that
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bilateral symmetry in all animals is homologous
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What is significant about cephalization
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A concentration of sensory organs allows better detection of threats for motile organisms
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Which phylum includes the most basal lineages of animals
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Porifera
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Why was the evolution of a coelom a critically important innovation for animals
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The coelom can act as a hydrostatic skeleton
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What reproductive trait is associated with terrestrial environments
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Internal fertilization
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Using the phylogenetic tree, where should the origin of swimming via rows of coordinated cilia occur
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At the base of Animalia
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The phyla Porifera, Cnidaria, and Ctenophora are
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the most ancient of all animal lineages
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Which of the following is an example of homology (similarity due to common ancestry)
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cnidocytes (stinging cells) in jellyfish and sea anemones
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The protostome developmental sequence arose just once in evolutionary history, resulting in two main subgroups—Lophotrochozoa and Ecdysozoa. What does this finding suggest
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Division of these two groups occurred after the protostome developmental sequence appeared
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The common ancestor of the protostomes had a coelom. What does this suggest
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The body cavity evolved before the lophophore
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The presence of a lophophore in a newly discovered species would suggest that the species
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is a suspension feeder
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What does phylogenetic evidence tell us about protostomes
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There were multiple transitions from water to land
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Nematodes and arthropods both
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grow by shedding their exoskeleton
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You find what you believe is a new species of animal. Which of the following characteristics would enable you to argue that it is more closely related to a flatworm than it is to a roundworm
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it has no coelom
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Lophotrochozoan phyla have a lophophore, a specialized structure for
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suspension feeding
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Long before humans invented it to power aircraft, jet propulsion evolved in
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cephalopod mollusks
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In adult arthropods, the hemocoel
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provides space for the internal organs to grow and function
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How do hemimetabolous and holometabolous metamorphosis differ
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Hemimetabolous metamorphosis is incomplete. Holometabolous metamorphosis is complete
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As a group, invertebrates are
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paraphyletic
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Which character would allow you to identify something as an echinoderm and not a chordate
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Radial symmetry
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What happens to a tide pool community if sea stars are excluded
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Mussel populations rapidly increase
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This phylum is exclusively marine and is named for having many spines and spikes
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echinoderms
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Which of the following is a characteristic of all chordates at some point during their life cycle
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post-anal tail
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The leading hypothesis for the origin of the jaw proposes that
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it resulted from mutations in the developmental regulatory genes that determine the morphology of the gill arches
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In which vertebrates did feathers first evolve
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non-avian dinosaurs
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Which vertebrates lay amniotic eggs
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reptiles and some mammals
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Estimate total population size in a mark-recapture study in which 200 individuals were initially marked, and you recaptured 150 of which 50 were marked
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600
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Given the data in the table, which survivorship curve does Lacerta viviparta best resemble
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Type II
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Why would life tables constructed in ancient Rome be different than those constructed for today's Romans
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The fecundity of today's individuals is lower
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What is rmax in a species like the giant panda
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It is low
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How might the line appear if unlimited food were provided
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The line would be horizontal
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In the figure above, which of the lines represents the highest per-capita rate increase (r)
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line A
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Hanski's study of fritillaries showed that
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metapopulations are dynamic over time
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What best explains hare and lynx population cycles
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the interaction of food availability and predation intensity
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Why does the age structure of human populations differ in developed versus developing nations
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This is because in developing countries, survivorship and the fertility rate have been increasing
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How can human population size keep increasing in spite of decreased fertility rates
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Population size will continue to increase as long as the average fertility is above the replacement rate
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In species like sea turtles with high juvenile mortality, low adult mortality, and low fecundity, conservationists can most effectively help them by
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focusing on keeping adults alive
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What is the fundamental niche of Chthamalus
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The upper and lower intertidal zones
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Which is an apt description of a coevolutionary arms race?
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Consumption driving the evolutionary escalation of species traits
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How might a mutualistic relationship between species evolve into a parasitic one?
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When one of the species stops receiving a benefit and also begins to incur a cost
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What is the combination of resources or areas used or conditions tolerated in the absence of competitors called
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a fundamental niche
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Bees visiting flowers to harvest nectar and pollen would be considered examples of
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mutualism
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What does the graph in the figure above tell you about the definition of a keystone species?
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Removing a keystone species from the community drastically reduces diversity.
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Robert Paine's experiment removing the predatory sea star Pisaster ochraceous from intertidal habitats showed that it
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was a keystone species
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Succession in an ecological context refers to
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the predictable sequence of changes in species composition over time within the community after a disturbance
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What makes pioneering plant species successful
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They rapidly colonize soil that is exposed and has few or no competitors already present.
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How might a conservation biologist apply the theory of island biogeography in a national park
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By ensuring large patches of forest are left undisturbed
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How would the species richness curves on an island be affected if mainland habitats were wiped out by urbanization
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It would lower the rate of immigration and increase the rate of extinction
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In an ecosystem, phytoplankton are
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producers
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An earthworm that feeds on the remains of plants and animals is acting as a
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detritivore
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When a human eats a steak, the human is acting as a
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secondary consume
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A cow eating grass is an example of a
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primary consumer
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A human who just ate a hamburger is eaten by a shark while swimming. The shark is acting as a
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tertiary consumer
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_____ are secondary consumers.
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Carnivores
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Approximately _____% of the energy at one trophic level is passed on to the next highest trophic level
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5-10
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10,000 kcal of producer could support approximately _____ kcal of tertiary consumer
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10
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Why does it take 10 times more energy to grow a kilogram of beef than a kilogram of wheat?
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Cattle only integrate 10 percent of their food into biomass
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Which is the most efficient food source to consume in terms of bioenergetics?
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fish
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Why might one get mercury poisoning from eating tuna every day, but not from eating sardines from the same water?
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Tuna biomagnify the mercury.
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Which of the following is a consequence of biological magnification (biomagnification)
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Toxic chemicals in the environment pose greater risk to top-level predators than to primary consumers.
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When wolves were reintroduced to Yellowstone, they caused changes in the populations of elk, coyotes, aspen, beaver, willows, mice, and hawks. The production of these far-reaching effects on the food web is known as _____.
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a trophic cascade
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Which habitats are the most productive
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the tropical rain forests and coral reefs
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Which human activity has the most direct impact on the global water cycle?
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Building of impervious city streets and sidewalks
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What conditions would lead to low decomposition rates in a marine environment?
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Lack of oxygen
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Carbon dioxide functions as a greenhouse gas because it _____.
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reflects heat radiated from the Earth back toward the Earth the way the glass of a greenhouse reflects heat
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What is the synapomorphy for eukaryotes
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Nuclear envelope
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How many membranes do chloroplasts in members of Plantae have
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2
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Are green plants monophyletic
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yes
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Are green algae monophyletic
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yes
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