Bio 2 Exam One Practice Questions

The analytical approach to understanding the diversity and relatedness of both extant and extinct organisms is called __________.systematics
What is the focus of the branch of biology called taxonomy?the classification of life-forms by their similarities and differences
The binomial system assigns to each organism a unique name that describes its __________.genus and species
The two-part format of the scientific name, referred to as binomial, ensures that __________.All of the listed responses are correct.
Which of the following is the correct taxonomic name for the African forest elephant?Loxodonta cyclotis (italics)
A taxon a formal grouping at any given level
Rabbits and guinea pigs both belong to class Mammalia. This means they must also both belong to __________. (eText Concept 26.1)phylum Chordata
Species A and species B are in the same phylum. Species A and species C, but not species B, are in the same order. From this information you can conclude that __________.species C could be in the same class as species A and B
What does a branch point in a phylogenetic tree represent?A branch point represents a point at which two evolutionary lineages split from a common ancestor.
Which of the following methods to establish phylogenetic relationships among organisms has been developed most recentlycomparing the amino acid sequences of proteins and nucleotide sequences of nucleic acids
The wings of a hummingbird and the wings of a bee are __________.analogous
Which of the following would be the LEAST useful in determining the relationships among various species?analogous structures
Researchers can use molecular homologies to __________.reveal the number of mutations in a particular sequence that has occurred in each species since they diverged from a common ancestor
A phylogenetic tree of bird families constructed by cladistic analysis would be a hypothesis about which of the following?evolutionary relationships among bird families
Many researchers who study the kingdom Protista argue that all of these organisms should NOT be placed in the same kingdom, because these organisms could not have evolved from a common ancestor. In other words, they argue that the kingdom Protista is __________.polyphyletic
Using cladistic analysis, a taxonomist wishes to construct a phylogenetic tree showing the relationships among various species of mammals. Which of the following would be the LEAST useful for this purpose?the fact that all mammals have hair
Which statement below is true about an outgroup? (eText Concept 26.3)The outgroup should be from a lineage known to have diverged before the lineage that includes the ingroup.
Unlike a regular phylogenetic tree, phylogenetic trees with branch lengths proportional to time can be used to __________.represent the chronological time that has passed since two groups diverged from a common ancestor
Which statement below is true of parsimonious trees?The most parsimonious tree requires the fewest evolutionary events to have occurred in the form of shared derived characters.
Birds and mammals have a four-chambered heart, but most reptiles have a three-chambered heart. How does this fact affect the construction of phylogenetic trees for these groups?The most likely tree is not always the most parsimonious.
If you wanted to determine the lineage of plants that have evolved on a relatively young archipelago—approximately 15,000 years old—what type of nucleic acid should you compare?mtDNA
Paralogous genes __________.result from gene duplication
What is the evolutionary significance of paralogous genes?They increase the size of the genome and provide more opportunity for the evolution of novel characteristics.
What is the evolutionary significance of orthologous genes?The high percentage of orthologous genes found in vastly different organisms emphasizes the many biochemical and developmental pathways shared by all organisms.
The idea of using molecules as clocks to time evolutionary events is very attractive, but there are many problems in actually applying the technique. What seems to be the best way to get reliable results?It is important to use as many genes as possible. With this approach, fluctuations in evolutionary rate will tend to average out
By applying a molecular clock, researchers have proposed that the first HIV-1 M invasion into humans occurred in the __________1930s
To which domain is the domain Eukarya (the domain to which humans belong) most closely related?It is not clear whether eukaryotes are more closely related to bacteria or archae
Universal phylogenetic trees built from different genes sometimes give inconsistent results. What basic assumption on which phylogenetic trees are based has probably been violated during the history of life?Genes are passed vertically from one generation to the next.
Why is salt a good preservative to use for foods such as pork and fish?Prokaryotic cells living in the food will shrink from their cell walls, impacting their ability to reproduce.
Gram-negative bacteria have __________ peptidoglycan than gram-positive cells, and their cell walls are __________ complex structurally.less … more
A gram-negative cell wall consists of __________.a thin layer of peptidoglycan surrounded by an outer membrane containing lipopolysaccharides
Bacteria that __________ tend to have abundant internal membranesare photosynthetic
Bacterial flagella have a very complex structure composed of 42 distinct proteins. What is the most likely explanation for the evolution of these complex structures?exaptation
The bacteria that cause tetanus can be killed only by prolonged heating at temperatures considerably above boiling. This suggests that these bacteria __________.produce endospores
Plasmids __________.All of the listed responses are correct.
How is it possible that as many as 9 million mutations can arise each day in the population of E. coli inhabiting one human?A large population size and a rapid reproduction rate combine to produce many mutations without a particularly high mutation rate.
In the absence of meiosis and sexual reproduction, what general process allows genetic recombination among prokaryotes?horizontal gene transfer
Which of the following statements about transformation is true?It can be facilitated by cell-surface proteins that recognize compatible DNA
An F+ bacterial cell __________.acts as a donor during conjugation
Which of the following is/are true about R plasmids?Both the second and third answers are correct.
Organisms that use light for their energy source and CO2 for their carbon source are called __________.photoautotrophs
In an experiment, a microbiologist put equal numbers of each of the following organisms into a flask of sterile broth, consisting mostly of sugar and a few amino acids. She then placed the flask in the dark. Which of the organisms would be most likely to survive?chemoheterotrophic bacteria
The Desulfovibrio bacterium breaks down organic matter (which it must have) and uses sulfate (not oxygen) as an electron acceptor. As a result, it produces hydrogen sulfide (H2S), accounting for the “rotten egg” smell of swamp muck. Oxygen is a deadly poison to Desulfovibrio. We would call Desulfovibrio a(n) __________.obligate anaerobic chemoheterotroph
Choose the list below that contains the substances required by typical nitrogen-fixing cyanobacteria.carbon dioxide, nitrogen, water, light, and some minerals
What is the role of heterocysts in a cyanobacterial filament?They carry out only nitrogen fixation.
Biofilms are an example of __________.metabolic cooperation among prokaryotic species
Portions of the genomes of certain prokaryotic species are very similar to portions of the genomes of distantly related prokaryotes. The process that most likely accounts for this genetic similarity is __________.horizontal gene transfer
Which subgroup of proteobacteria contains many species that are closely associated with eukaryotic hosts in mutualistic or parasitic relationships?alpha
Which subgroup of proteobacteria contains many species that are predators of other bacteria? (eText Concept 27.4)delta
Which group of bacteria is unusual in that they lack peptidoglycan in their cell walls? (eText Concept 27.4)chlamydias
Which of the following is a difference between bacteria and archaea? (eText Concept 27.4)They have different chemicals in their cell membranes and cell walls
Which of the following statements about cyanobacteria is/are true?All of the listed responses are correct.
Prokaryotes found inhabiting the Great Salt Lake would be __________.extreme halophiles
Which of the following groups of prokaryotes is classified as a member of the domain Archaea? (eText Concept 27.4)methanogens
Which clade of archaea includes most of the extreme thermophiles?Crenarchaeota
Prokaryotes are completely indispensable to which chemical cycle? (eText Concept 27.5)nitrogen
A type of ecological relationship called __________ involves one organism living at the expense of another organism.parasitism
Which example below is a correct statement about Bacteroides thetaiotaomicron, a bacterium that lives in the human intestines?The bacteria have a mutualistic relationship with the human body.
Ticks that live on deer and field mice are responsible for spreading the bacterium __________, which causes __________. (eText Concept 27.6)Borrelia burgdorferi … Lyme disease
Which statement is true regarding cholera? (eText Concept 27.6)Its symptoms are caused by an exotoxin that stimulates intestinal cells to release chloride ions into the gut.
Scientists hypothesize that the O157:H7 strain of E. coli is so different from the K-12 strain because of __________. (eText Concept 27.6)horizontal gene transfer over many years, most likely through the action of bacteriophages
Which statement about prokaryotes is true? (eText Concept 27.6)Prokaryotes are widely used for bioremediation.
Why have protists been “mixed in” with plants, animals, and fungi under the hypothesis that groups eukaryotes into five supergroups? (eText Overview)Many protists are more closely related to plants, animals, or fungi than they are to each other.
The placement of all protists in one kingdom caused dissatisfaction among taxonomists mainly because __________. (eText Concept 28.1)various pieces of evidence indicate that the kingdom Protista cannot be monophyletic
Which of the following is one of the main weaknesses of the proposed classification scheme in which all eukaryotes are divided into four supergroups? (eText Concept 28.1)It shows all four supergroups diverging simultaneously from a common ancestor.
Organisms are classified as Excavata based on __________. (eText Concept 28.2)morphological studies of the cytoskeleton
Which example below is a characteristic shared by diplomonads and parabasalids? (eText Concept 28.2)Both lack plastids.
How do trypanosomes withstand the attack of a host’s immune system? (eText Concept 28.2)The molecular composition of their surface changes continually.
Which of these groups includes photosynthetic unicellular organisms with flagella and contractile vacuoles? (eText Concept 28.2)euglenids
Apicomplexans are currently assigned to the SAR clade because __________. (eText Concept 28.3)the apicoplast, a modified plastid, appears to be of red algal origin
In many types of protist life cycles, the union of two gametes that results in a diploid zygote is called __________. (eText Concept 28.3)syngamy
What do a carnivorous dinoflagellate, a parasitic apicomplexan, and a ciliate have in common? (eText Concept 28.3)All three have sacs known as alveoli just beneath their plasma membranes.
Which organisms are capable of producing a “red tide”? (eText Concept 28.3)dinoflagellates
Which of these groups includes species that produce a substance that is toxic to humans? (eText Concept 28.3)dinoflagellates
Which of these groups includes parasitic unicellular organisms with a complex of organelles specialized for penetrating host cells and tissues?apicomplexans
Which of these groups is characterized by cells that have more than one nucleus? (eText Concept 28.3)ciliates
How do ciliates generate genetic variation? (eText Concept 28.3)conjugation
Which of these groups includes unicellular organisms that, due to the structure of their cell walls, can withstand pressures equal to the pressure under each leg of a table supporting an elephant? (eText Concept 28.3)diatoms
Which characteristic is/are shared by most diatoms, golden algae, and brown algae at least at some stage of their life cycles? (eText Concept 28.3)All of the listed responses are correct.
What is the purpose of the “floats” in some brown algae? (eText Concept 28.3)facilitating photosynthesis
Which of the following organisms is commercially harvested to extract algin from their cell walls? (eText Concept 28.3)brown algae
What role do diatoms play in the global carbon balance affecting global warming? (eText Concept 28.3)During a bloom, diatom populations may increase rapidly. If many diatoms die and sink to the bottom without being eaten, they effectively pump carbon dioxide out of the atmosphere.
On some areas of the seafloor, one could observe an “ooze” that is hundreds of meters thick. What creates this ooze? (eText Concept 28.3)the tests of dead radiolarians
Many species of red algae are adapted to deeper water due to the fact that __________. (eText Concept 28.4)their photosynthetic pigments efficiently absorb blue and green light
Which of the following groups of algae is/are most closely related to land plants? (eText Concept 28.4)green algae
In lab class, a plasmodial slime mold is used as a demonstration organism. One of the students does not understand why this organism is not considered multicellular. How would you explain it to her? (eText Concept 28.5)The plasmodium is undivided by membranes and contains many diploid nuclei; therefore, it is not technically multicellular.
To which of the four eukaryotic supergroups do amoebas belong? (eText Concept 28.5)None of the listed responses is correct.
The red algae are characterized by __________. (eText Concept 28.5)diverse life cycles, including alternation of generations
What percentage of the world’s photosynthesis is carried out by protists? (eText Concept 28.6)about 30%
__________ is a protist that causes late blight of potatoes and was responsible for the Irish potato famine of the 19th century. (eText Concept 28.6)Phytophthora infestans
Hypermastigotes are important endosymbionts that live in the guts of __________. (eText Concept 28.6)termites
Which of the following statements about algae and plants is true? (eText Concept 29.1)Plants have a waxy, waterproof cuticle, and algae do not.
Which of the following homologies is/are shared by land plants and their closest living algal relatives? (eText Concept 29.1)All of the listed responses are correct.
In moving to land, which of the following challenges did plants have to overcome? (eText Concept 29.1)desiccation
Alternation of generations __________. (eText Concept 29.1)is distinguished by haploid and diploid stages that are both multicellular
Plants undergo alternation of generations in which __________. (eText Concept 29.1)the sporophyte generation alternates with the gametophyte generation
Gametangia are __________. (eText Concept 29.1)single-celled in algae, multicellular in most plants
In charophytes, __________ protect(s) zygotes from desiccation. (eText Concept 29.1)sporopollenin
Which is a key difference between alternation of generations in plants and sexual reproduction in nonplant organisms? (eText Concept 29.1)In plants, the haploid and diploid stages are both multicellular.
The development of the __________ prevents plants from drying out and protects them from microbes. (eText Concept 29.1)cuticle
Which example below is a clade of nonvascular plants? (eText Concept 29.1)bryophytes
Which term is most nearly synonymous with land plants? (eText Concept 29.1)embryophytes
A major division in plant systematics is based on whether a particular species has __________. (eText Concept 29.1)vascular tissue
The gametophyte stage of the plant life cycle is most conspicuous in __________. (eText Concept 29.2)mosses
What structures allow plants to readily take up carbon dioxide from the atmosphere? (eText Concept 29.1)stomata
When you see a green, “leafy” moss, you are looking at the __________. (eText Concept 29.2)gametophyte generation
Rhizoids __________.anchor the gametophytes of bryophytes
Which of the following produces eggs and sperm? (eText Concept 29.2)moss gametophytes
Fertilization in moss occurs when sperm swim from a(n) __________ and down the neck of a(n) __________. (eText Concept 29.2)antheridium … archegonium
The gametophyte generation of a moss __________. (eText Concept 29.2)is haploid
How are gametes produced by bryophytes? (eText Concept 29.2)by mitosis of gametophyte cells
In mosses, haploid __________ directly produce buds that grow into gametophores. (eText Concept 29.2)protonemata
Which structure of a bryophyte sporophyte is specialized for gradual spore discharge? (eText Concept 29.2)peristome
In which bryophyte structure specifically does a zygote develop into an embryo?(eText Concept 29.2)archegonium
Sphagnum is a __________ that forms extensive deposits of partially decayed organic material. (eText Concept 29.2)moss
In the life cycle of a fern, the multicellular male gametangium (the sex organ that produces sperm cells) is called a(n) __________. (eText Concept 29.3)antheridium
In the life cycle of ferns, the multicellular female gametangium (the sex organ that contains an egg) is a(n) __________. (eText Concept 29.3)archegonium
Ferns and mosses are limited mostly to moist environments because __________. (eText Concept 29.3)they have swimming sperm
What is the evolutionary significance of megaphylls? (eText Concept 29.3)They increase the surface area for photosynthesis.
The “dots” on the underside of a fern frond are spore cases; therefore, what is true of the plant to which the frond belongs?It is a sporophyte.
Where would you find a fern gametophyte?on moist soil
Fern gametophytes are __________. (eText Concept 29.3)free-living, multicellular organisms
To examine meiosis in ferns, you would study __________. (eText Concept 29.3)the sporangia
Vascular tissues of plants include __________. (eText Concept 29.3)xylem for conducting water and minerals, and phloem for conducting dissolved organic molecules
Heterosporous plants produce __________. (eText Concept 29.3)megaspores that develop into female gametophytes and microspores that develop into male gametophytes
Sori can be found in which of the following? (eText Concept 29.3)pterophytes
In sporophyte ferns, the leaves are __________. (eText Concept 29.3)megaphylls
The first large forests formed in the Carboniferous Period. The decrease in CO2 levels by all of these plants caused __________. (eText Concept 29.3)global cooling
Which of the following adaptations is common to all seed plants? (eText Concept 30.1)All of the listed responses are correct.
Which one of the following is true of seed plants, but NOT true of seedless plants? (eText Concept 30.1)The gametophyte is reduced and dependent on the sporophyte.
The closest seedless relatives of seed plants produce one kind of spore that gives rise to a bisexual gametophyte. What does this suggest about the ancestors of seed plants? (eText Concept 30.1)They were homosporous.
The eggs of seed plants are fertilized within ovules, and the ovules then develop into __________. (eText Concept 30.1)seeds
The cells within pollen grains are __________ and together comprise the __________. (eText Concept 30.1)haploid … male gametophyte
Which example below is evidence provided by living gymnosperms of an evolutionary transition between seedless and seed plants? (eText Concept 30.1)The sperm of some gymnosperms have flagella.
Which of the following best states the advantages that seeds have over spores? (eText Concept 30.1)Seeds contain embryonic plants, an abundant food supply, and a protective covering.
Which gymnosperm phylum is characterized by large cones and fern-like leaves and thrived during the Mesozoic? (eText Concept 30.2)Cycadophyta
Dietary supplements and decongestants containing ephedrine have recently become more strongly regulated in the United States. Which phylum contains the plant from which ephedrine is extracted? (eText Concept 30.2)phylum Gnetophyta
What global change occurring between the Carboniferous period and the Permian period likely contributed to the success of the gymnosperms? (eText Concept 30.2)The climate became drier and warmer.
What is located in the scalelike structures packed densely in pollen cones? (eText Concept 30.2)sporangia
Each pollen grain of a gymnosperm contains a __________. (eText Concept 30.2)male gametophyte
In ovulate cones, megasporocytes undergo __________ and produce __________ megaspores. (eText Concept 30.2)meiosis … haploid
In a typical conifer, how long does it take for fertilization to occur after pollination? (eText Concept 30.2)It takes one year.
The diploid generation of the plant life cycle always __________. (eText Concept 30.3)produces spores
Which types of angiosperms would most likely be wind-pollinated rather than animal-pollinated? (eText Concept 30.3)The first and second responses are correct.
Like gymnosperms, many grasses and angiosperm trees are wind-pollinated. To conserve energy, these angiosperms do not produce complete flowers (complete flowers have all four of the basic parts). Which part would be unnecessary for wind-pollinated angiosperms? (eText Concept 30.3)petals
The portion of a flower that receives the pollen is the __________. (eText Concept 30.3)stigma
During pollination, pollen grains are transferred from the __________ to the __________. (eText Concept 30.3)anther … stigma
A pea pod is formed from __________. A pea inside the pod is formed from __________. (eText Concept 30.3)an ovary … an ovule
After fertilization, the __________ develops into a seed and the __________ develops into a fruit. (eText Concept 30.3)ovule … ovary
Which of the following best describes the function of fruits? (eText Concept 30.3)protection and dispersal of seeds
A plant is said to be cross-pollinated if __________. (eText Concept 30.3)pollen grains are transferred to a flower on a different plant
The pollen tube releases two sperm cells into the embryo sac. The result of this is the __________. (eText Concept 30.3)union of one sperm nucleus with the egg nucleus and of the other sperm nucleus with two nuclei of the central cell, forming a triploid nucleus called the endosperm
Of the following, which is a difference in how reproduction occurs in gymnosperms compared to angiosperms? (eText Concept 30.3)Only the sperm of angiosperms combine with two central cell nuclei to form triploid endosperm.
The triploid nucleus of the embryo sac develops into the __________. (eText Concept 30.3)endosperm
In gymnosperms, the seed coat develops from the integument. In angiosperms, the seed coat develops from the __________. (eText Concept 30.3)integuments
The vast majority of angiosperms with two cotyledons formerly classified as __________ are now classified as __________. (eText Concept 30.3)dicots … eudicots
Which of the following lists of features characterizes eudicots? (eText Concept 30.3)two cotyledons, netlike veins, taproot usually present
A bright pink flower with deep floral tubes will most likely be pollinated by which mechanism? (eText Concept 30.3)birds with long beaks
Six major crops˜wheat, rice, maize, potatoes, cassava, and sweet potatoes˜contribute disproportionately to human diets. What percentage of all the calories consumed by humans is supplied by these crops? (eText Concept 30.4)80%
At current rates of deforestation, tropical rain forests will be eliminated in __________ years. (eText Concept 30.4)200
Besides the plant tissue that humans ingest, which angiosperm tissue is most directly important for human survival? (eText Concept 30.4)xylem
Fungi are __________ organisms.chemoheterotrophic
__________ fungi absorb nutrients from living organisms.(eText Concept 31.1)The first and second responses are both correct.
There is a fungus in Oregon that covers 890,965 hectares! The bulk of this fungus is most likely _____. (eText Concept 31.1)mycelia
In fungi, the function of the mycelium is _____. (eText Concept 31.1)obtaining food
Fungi that consist of a continuous mass containing hundreds or thousands of nuclei are known as _____. (eText Concept 31.1)coenocytic
Parasitic fungi possess hyphae that are modified to penetrate and absorb nutrients from host tissue. Such modified hyphae are called _____. (eText Concept 31.1)haustoria
You can buy mycorrhizal fungus to add to soil when you plant trees and other plants. Why would you want to do this? (eText Concept 31.1)Mycorrhizal fungi assist plants in the absorption of essential nutrients.
The cell walls of fungal cells are composed of _____. (eText Concept 31.1)chitin
Which choice below generally represents the correct order of events in fungal sexual reproduction? (eText Concept 31.2)plasmogamy, karyogamy, meiosis, germination
Which of the following statements about fungi is/are true? (eText Concept 31.2)All of the listed responses are correct.
What role do pheromones play in fungal sexual reproduction? (eText Concept 31.2)Fungi use these chemical signals to determine whether a potential sexual partner is of a suitable mating type.
Hyphae with two nuclei per cell are called _____. (eText Concept 31.2)dikaryotic
During what stage of fungal reproduction are diploid cells produced? (eText Concept 31.2)karyogamy
Fungal species are assigned to particular phyla based on _____. (eText Concept 31.2)the type of sexual structure they form
Molecular evidence suggests that fungi _____. (eText Concept 31.3)and animals have a common ancestor
Evidence that mycorrhizae, the mutualistic relationship between plants and fungi, existed from the beginning of the colonization of land comes from _____. (eText Concept 31.3)fossils
Which feature below is unique to chytrids? (eText Concept 31.4)zoospores (flagellated spores)
Which statement below about zygosporangia is/are true? (eText Concept 31.4)All of the listed responses are correct.
What is the major feature of glomeromycetes? (eText Concept 31.4)arbuscules
An ascus is _____. (eText Concept 31.4)a saclike structure containing spores
The asexual spores produced by members of the phylum Ascomycota are called _____. (eText Concept 31.4)conidia
The mushroom in a basidiomycete life cycle serves the same function as the _____ in the ascomycete life cycle, which is to _____. (eText Concept 31.4)ascocarp … scatter sexually produced spores
While hiking through a forest, you discover a fungus growing on the remains of a decaying tree trunk. You hypothesize that it is a basidiomycete fungus because it resembles a mushroom in shape and size. If your logic is correct, microscopic analysis of the tissue found in the stalk of this fungus will reveal the presence of _____. (eText Concept 31.4)dikaryotic cells with haploid nuclei
Fungi in the phylum Basidiomycota are the most important decomposers of wood because of their ability to break down _____. (eText Concept 31.4)lignin
What is the importance of the extended dikaryotic stage in the life cycles of basidiomycetes and ascomycetes? (eText Concept 31.4)It allows for more genetic recombination.
Where and when does fertilization occur in the mushroom life cycle? (eText Concept 31.4)in a mushroom, when the nuclei of a dikaryotic cell fuse
Lichens are _____. (eText Concept 31.5)symbiotic associations of photosynthesizers and fungi
Lichens are important pioneers in areas that have been burned by fires or destroyed by lava flows because _____. (eText Concept 31.5)they are important in the initial stages of soil formation
A dramatic example of the pathogenicity of certain fungi is the dramatic decrease of the American chestnut tree by _____. (eText Concept 31.5)ascomycete
Two of the most common mycoses (fungal infections) in humans are _____. (eText Concept 31.5)athlete’s foot and Candida (yeast) infections