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250 Cards in this Set

  • Front
  • Back
Despite years of research, the actual structure of the DNA molecule is still unknown.
false
Multiple DNA polymerase may become attached to more than one portion of a DNA molecule at once, speeding up the rate of replication.
true
During transcription, the information on a DNA molecule is "rewritten" into an mRNA molecule.
true
It has been discovered that each species of organism has its own unique genetic code for synthesis of its proteins.
false
A codon signifies a specific amino acid or a stop signal.
true
The primary function of DNA is to
a. make proteins
b. store and transmit genetic info.
c. control chemical processes within cells
d. prevent mutations
b.
All of the following are true about the structure of DNA except
a. short strands of DNA are contained in chromosomes inside the nucleus of a cell
b.every DNA nucleotide contains a sugar, a phosphate group, and a base.
c. DNA consists of two strands of nucleotides joined by hydrogen bonds
d. the long strands of nucleotides are twisted into a double helix
a.
Molecules of DNA are composed of long chains of what?
nucleotides
Which of the following is not part of a molecule of DNA?
a. deoxyribose
b. nitrogenous base
c. phosphate
d. ribose
d.
A nucleotide consists of what 3 things?
a sugar, a phosphate group, and a nitrogen-containing base
The part of the molecule for which deoxyribonucleic acid is named is the what?
sugar
Purines and pyrimidines are
a. bases found in amino acids
b. able to replace phosphate group from defective DNA
c. names of specific types of DNA molecules
d. bases found in nucleotides
d.
Who are the two scientists credited with establishing the structure of DNA?
Watson and Crick
Watson and Crick built models that demonstrated that
a. DNA and RNA have the same structure
b. the DNA helix is held together by hydrogen bonds
c. guanine forms hydrogen bonds with adenine
d. thymine forms hydrogen bonds with cytosine
b.
According to the base-pairing rules, what are the base pair in DNA?
adenine-thymine; guanine-cytosine
The attachment of nucleotides to form a complementary strand of Dna
a. is catalyzed by DNA polymerase
b. is accomplished only in the presence of tRNA
c. prevents seperation of complementary strands of RNA
d. is the responsibility of the complementary DNA mutagens
a.
The enzymes responsible for adding nucleotides to the exposed DNA template bases are what?
DNA polymerases
The function of rRNA is to what?
form ribosomes
Which type of RNA carries instructions for making proteins?
mRNA
RNA differs from DNA in that RNA
a. is sometimes single-stranded
b. contains a different sugar molecule
c. contains the nitrogen base uracil
d. all the above
d.
Which of the following is not found in DNA?
a. adenine
b. cytosine
c. uracil
d. none of the above
c.
RNA os chemically similar to DNA except that its sugars have an additional oxygen atom, and the base thymine is replaced by a structurally similar base called what?
uracil
In RNA molecules adinine is complementary to what?
thymine
Name the three types of RNA.
messenger, ribosomal, and transfer
In order for protein synthesis to occur, mRNA must migrate to where?
ribosomes
During transcription
a. proteins are synthesized
b. DNA is replicated
c. RNA is produced
d. translation occurs
c.
Transcription proceeds when RNA polymerase
a. attaches to a ribosome
b. binds to a strand of DNA
c. binds to a strand of RNA
d. attaches to a promoter molecule
b.
Transcription is the process by which genetic information encoded in DNa is transferred to a what?
RNA molecule
Each nucleotide triplet in mRNA that specifies a particular amino acid is called a what?
codon
Introns are the portions of a gene that actually get translated into proteins.
false
Introns are inert segments of DNA.
true
A mutation in a homeotic gene can result in the formation of legs in parts of the DRrosophila body that normally do not have legs.
true
Specific homeoboxes control the morphogenesis of specific parts of an adult organism.
true
The operator portion of an operon controls RNA polymerase's acces to structural genes.
true
Specific homeoboxes control the morphogenesis of specific parts of an adult organism.
true
When mRNA leaves the nucleus and enters the cytoplasm, it has a complete set of both introns and exons.
false
Cells regulate gene expression so that each gene will only be transcribed when it is needed.
true
The difference between oncogenes and tumor-suppressor genes is that oncogenes are mutant forms of genes that lack the ability to regulate cell division and tumor-suppressor genes are genes that regulate cell division but can lose this ability if they become mutated.
true
Introns are deleted before being transcribed from DNA into mRNA
false
A substance that causes cancer is known as a what?
carcinogen
In prok. cells, a group of genes that code for functionally related proteins is a what?
operon
Cells must control gene expression so that
a. their genes will always be expressed
b. their genes will only be expressed when needed
c. genetic disorders can be corrected
d. their genes will never be expressed
b.
What type of gene codes for a repressor?
regulator
Which of the following is not part of morphogenesis?
a. the formation of liver cells that produce enzymes that break down fat
b. the formation of cellular extensions in nerve cells and the functioning of these cells in receiving and transmitting signals
c. the formation of a zygote
d. the formation of long, thin muscle cells that are able to respond to the proper stimulus by contracting
c
Which of the following is not characteristic of homeoboxes?
a. they determine what species of organism will develop from a zygote
b. the produce regulatory proteins that switch on or off groups of developmental genes
c. they are genes
d. each controls the development of a specific part of the adult organism
a
Inducer molecules allow transcription to proceed by
a. unwinding the cells DNA molecules
b. destroying repressor molecules
c. changing the shape of repressor molecules
d. activating the ribosomes
c.
An oncogene
a. metastasizes to other chromosomes
b. induces numerous mutations of the chromosome on which it is found
c. may cause a cell to become a cancer cell
d. prevents a cell from reproducing
c.
An inducer molecule functions by
a. binding the rRNA subunits of a ribosome
b. digesting lactose molecules in bacterial cells
c. causing DNA replication
d. removing a repressor molecule from an operator
d.
The lac operon is shut of when what?
lactose is absent
What must happen in order for a eukaryotic gene to be expressed?
a. a repressor must be present
b. a repressor must be absent
c. the enhancer must be inactivated
d. the enhancer must be activated
d
metastasis is characterized by
a. spread of malignant cells beyond their original site
b. localization of a tumor to a particular location
c. the growth of a benign tumor
d. conversion of a malignant tumor to a benign tumor
a
Cells grow and divide at an abnormally high rate in what?
cancer
In order for RNA polymerase to attach to a DNA molecule,
a. an inducer must attach to the RNA polymerase molecule
b. an activator must initiate unwinding of DNA
c. translation must be completed
d. transcription must frist occur
b
A repressor protein
a. destroys amino acids before protein synthesis occurs
b. blocks movement of RNA polymerase
c. attaches to ribosomes during translation
d. prevents DNA synthesis
b
The portions of DNa molecules that actually code for the production of proteins are called what?
exons
The noncoding portions of DNA that are seperated from the portions of DNA actually used during transcription are called
introns
The function of an operator is to
a. generate amino acids for protein synthesis
b. regulate access of RNa polymerase to structural genes
c. control the process of transcription within the nucleus
d. turn on and off the molecules of tRNA
b.
Where on the lac operon does a repressor molecule bind when lactose is absent?
to the operator
Which of the following is not true of chromosome maps?
a. they depict the linear sequence of genes on a chromosome
b. they are constructed using crossing-over data from mating experiments
c. they depict absolute differences between genes on a chromosome
d. they are practical with species having only a few chromosome
c
A mutation caused by a piece of DNA breaking away from its chromosome and becoming attached to a nonhomologous chromosome is called what?
translocation
A change in a gene due to damage or being copied incorrectly is called what?
a mutation
The effects of mutation can be
a. helpful
b. harmful
c. neutral
d. all
d
A diagram in which several generations of a family and the occurence of certain genetic characteristics are shown is called a waht?
pedigree
Which of the following traits is controlled by multiple alleles in humans?
a. sickle cell anemia
b. blood type
c. hemophilia
d. pattern baldmness
b
What would be the blood type of a person who inherited an A allele from one parent and an O allele from the other?
type A
Which of the following describes hemophilia?
a. multiple-allele trait
b. dominant trait
c. sex-linked trait
d. codominant trait
c
Genetic counseling is a process that
a. helps identify parents at risk for having children with genetic defects
b. assists parents in deciding whether or not to have children.
c. uses a family pedigree
d. all
d
While studying several generations of a particular family, a geneticist observed that a certain disease was found equally in males and females and that all children who had the disease had parents who also had the disease. The gene coding for this disease is probably what?
autosomal dominant
If both parents carry the recessive allele that causes cystic fibrosis, the chance that their child will develop the disease is
a. one in two
b. one in four
c. two in five
d. 100 percent
b
If a characteristic is sex-linked, it
a. occurs most commonly in males
b. occurs only in females
c. can never occur in females
d. is always fatal
a
Since the allele for colorblindness is located on the X chromosome, colorblindness
a. cannot be inherited
b. occurs only in adults
c. is sex-linked
d. none
c
People with Down syndrome have how many chromosomes?
47
Trisomy is a mutation that results in a cell having an extra what?
chromosome
If nondisjunction occurs,
a. there will be too many gametes produced
b. no gametes will be produced
c. a gamete will receive too many or too few homologues of a chromosome
d. mitosis cannot take place
c
Genetic engineering techniques can be used to make crops resistant to destructive insects.
true
Genetic engineering can be used to move genes from the chromosomes of one organism into those of another.
true
Despite the potential enviornmental benefits, genetic engineers have been unable to develop crop plants that are resistant to weedkillers.
false
Gene cloning is an efficient way to produce many copies of a specific gene.
true
The "sticky ends" of a DNA fragment can combine with any other DNA fragment cut by the same restriction enzyme.
true
The effort to catalog, locate, and sequence all the chromosomes of every living organism is called the Human Genome Project.
true
Recombinant DNA is usually composed of DNA segments obtained from two different organisms.
true
Scientist have used genetic engineering to produce bacteria capable of synthesizing human proteins.
true
Restriction enzymes are used to cut DNA molecules into pieces.
true
A DNA fingerprint is a pattern of bands made up of specific fragments from an individual's DNA.
true
A ring of DNA in a bacterium is called a plasmid.
true
If a crop is made herbicide-resistant, treating it with an herbicide will seriously reduce its yield.
false
The goal of the Human Genome project is to
a. create maps showing where chromosomes are located on human genes
b. create maps showing where genes are located on human chromosomes
c. identify people with genetic diseases
d. treat patients with genetic diseases
b
Restriction enzymes are specific in their identification of what?
base sequences
Restriction fragment length polymorphism analysis is the procedure used for
a. DNA fingerprinting
b. creating plasmids in bacterial cells
c. making recombinant DNA
d. cloning cells that might contain specific genes of interest.
a
PCR and DNA replication
a. requier the same ingredients to make copies of DNA
b. are used in genetic engineering to make copies of RNA
c. are used in genetic engineering tomake proteins
d. none
a
Genetic engineering of crop plants to make them resistant to weed killers is important because
a. weed killers also kill moth and butterfly larvae
b. many weed killers remain active for years
c. the cost of producing these crops is less since they do not need to be weeded
d. it increases erosion of topsoil
c
transferring normal human genes into human cells that lack them
a. will cause cancer
b. is impossible at this time
c. will cause antibodies to kill those cells
d. is called gene therapy
d.
If major cash crops could be genetically engineered to carry out nitrogen fixation
a. plants would be able to absorb n2 from the air and convert it to a useful form
b. the cost of cultivating the crops would be considerably reduced
c. the need for nitrogen fertilizers would be greatly reduced
d. all of the above
d
A gene that codes for resistance to an herbicide has been added to the genome of certain plants. These plants will
a. produce chemicals that kill weeds growing near them
b. die when exposed to the herbicide
c. convert the herbicide to fertilizer
d. survive when the herbicide is sprayed on the field
d
Plasmids
a. can replicate independently of the organism's main chromosome
b. are often used as vectors in genetic engineering experiments
c. are circular pieces of bacterial DNA
d. all
d
Fragments of DNA having complementary "sticky ends"
a. are found only in bacterial cells
b. can join with each other
c. are immediately digested by enzymes in the cytoplasm of the cell
d. can join only with complementary fragments of the same species
b
The use of genetic engineering to transfer human genes into bacteria
a. is impossible with current technology
b. allows the bacteria to produce human proteins
c. causes the human genes to manufacture bacterial proteins
d. results in the formation of a new species of organism
b
Cloning is a process by which
a. many identical DNA fragments are produced
b. undesirable genes may be eliminated
c. many identical cells may be produced
d. a virus and a bacterium may be fused into one
c
Enzymes that cut DNA molecules at specific places
a. always break the DNA between guanine and adenine
b. work only on bacterial DNA
c. have sticky ends
d. are restriction enzymes
d
a genome is
a. a fragment of DNA added to a chromosome during a gene transfer experiment
b. the nucleotide sequence that makes up a particular gene
c. a process used to copy DNA
d. an organism's collection of genes
d
The red maple is also known as Acer rubrum. Its scientific name is what?
Acer rubrum
THe scientific name of an organism
a. is the same for scientists all over the world
b. may refer to more than one species
c. may have more than one genus name
d. vaires according to the native language of scientists
a
Today, biologists classify organisms by their
a. physical similarities
b. behavioral similarities
c. chemical similarities
d. all
d
Taxonomy is defined as the science of
a. studying reproductive mechanisms and gene flow
b. classifying plants according to their uses in agricultural experiments
c. grouping organisms according to their characteristics and evolutionary history
d. studying ribosomal RNA sequencing techniques
c
Nearly all single-celled eukaryotes that are either heterotrophic or photosynthetic belong to which kingdom?
Protista
Two organisms in the same class but different orders will
a. be in different kingdoms
b. be in the same phylum
c. have the same genus name
d. be members of the same species
b
The correct order of the biological hierarchy from kingdom to species is
a. kingdom, class, order, phylum, family genus, species
b. kingdom, phylum, class, order, family, genus, species
c. kingdom, class, family, order, phylum, genus species
d. kingdom, phylum, order, family, class, genus, species
b
A mushroom is difficult to classify in Linnaeus's two-kingdom classification system because
a. mushrooms had not yet evolved in Linnaeus's time
b. it doesn't seem to fit into either category
c. it has another common name, the toadstool
d. all
b
The catchall kingdom is which kingdom?
Protista
Kingdoms are divided into phyla, and a phyulm is divided into what?
classes
Most multicellular, nucleated autotrophs that carry on photosynthesis belong to which kingdom?
plantae
An organism can have
a. one genus name and two species identifiers
b. two scientific names if it is found on different continents
c. two genus names but only one species identifier
d. one genus name and one species identifier
d
Simple, non-nucleated organisms that use hydrogen to produce methan are in which kingdom?
Archaebacteria
Multicellular, nucleated heterotrophs that always obtain food by absorbing nutrients from the enviornment belong to which kingdom?
Fungi
Scientists don't use the common names of organisms because
a. an organisms may have more than one common name
b. common names are too ambiguous
c. an organism rarely has the same name in different languages
d. all
d
Poison ivy is also known as Rhus toxicondendron. Its species identifier is
a. toxicondendron
b. poison
c. ivy
d. Rhus
a
An organism that breaks down organic matter, which it then absorbs, is in which kingdom?
Fungi
Which scientist developed the system of classifying organisms by assigning them a genus and species name?
Linnaeus
Archaebacteria can be distinguished from eubacteria because of differences in their
a. gene architecture
b. cell membranes
c. cell walls
d. all
d
As we move through the biological hierarchy from the kingdom to species level, organisms
a. are less and less related to each other
b. always are members of the same order
c. vary more and more
d. become more similar in appearance
d
The organism Quercus phellos is a member of which genus?
Quercus
Scientific names are written in what language?
latin
Which of the following is the least inclusive classification group?
a. phylum
b. genus
c. class
d. species
d
Which of the following types of characteristics is used in systematic taxonomy to organize organisms?
a. morphology
b. patterns of embryological development
c. amino acid sequences of proteins
d. all
d
If CFC's were to be banned by all countries tomorrow, the destruction of the ozone layer would quickly be stopped.
false
Ecologists all the physical location of a community its habitat.
true
An organisms's range can be determined by its tolerance to only one envionmental variable.
true
While an understanding of the interactions between organisms and their envionrment was very important to early hunter and gatherer humans, it is even more important today because humans are having significant effects on the enviornment.
true
A community includes all the species within an area
true
CFC's are the only chemicals that destroy ozone in the atmosphere.
false
An organism's niche is the sum of all its interactions in its envionment, including interactions with other organisms.
true
Cutting down trees in a forest alters the habitat of the organisms living in the forest.
true
Ecosystems include only the biotic factors in an area.
false
The destruction of the ozone layer maybe responsible for an increase in
a. cataracts
b. cancer of the retina
c. melanoma
d. all
d
A group of organisms of different species living together in a particular place is called what?
community
CFC's in the atmosphere
a. convert sunlight into ozone
b. stick to frozen water vapor
c. convert ozone into methane
d. change oxygen into ozone
b
The heat-trapping ability of some gases in the atmosphere can be compared to
a. heating water on a stove
b. the way glass traps heat in a greenhouse
c. condensation due to heating
d. the melting of snow
b
An organisms niche includes
a. where it eats
b. what it eats
c. when it eats
d. all
d
The physical location of an ecosystem in which a given species lives is called a what?
habitat
An ecosystem consists of
a. a community of organisms
b. energy
c. the soil, water, and weather
d. all
d
CFC's were once
a. thought to be chemically inert
b. used as aerosol propellants
c. used as refrigeratns
d. all
a
Temperatures may increase on Earth because
a. decomposers essential to recycling matter are being destroyed
b. Earth tilts toward the sun in the summer
c. increasing carbon dioxide would trap more heat
d. too much oxygen is now given off by plants
c
If the niches of two organisms overlap,
a. both organisms will disappear from the habitat
b. one organism usually migrates to a new habitat
c. the organisms may have to compete directly
d. the organisms will always from a symbiotic relationship
c
Which of the following is not an adaptation for avoiding unfavorable conditions?
a. migration
b. acclimation
c. body temperature regulation
d. dormancy
b
Ecological models are useful for
a. evaluating proposed solutions to envionmental problems
b. making predictions about future ecological changes
c. testing predictions about future ecological changes
d. all
d
Ecology is the study of the interaction of living organisms
a. with each other and their habitat
b. and the the food they eat
c. with each other and their physical envionment
d. and their communities
c
Rising costal sea levels are expected to result from what?
global warming
Which of the following would not be included in a description of an organism's niche?
a. the humidity and temperature it prefers
b. its number of chromosomes
c. its trophic level
d. when it reproduces
b
A relationship between a producer and consumer is best illustrated as
a. a fox eating a mouse
b. a lion eating a zebra
c. a zebra eating grass
d. a snake eating a bird
c
Parasites
a. are usually smaller than their hosts
b. rarely kill their hosts
c. coevolve with their hosts
d. all
d
A tick feeding on a human is an example of what?
parasitism
Which of the following is an example of mimicry?
a. coloration that causes an animal to blend in with its habitat
b. a harmless species that resembles a poisonous species
c. similarly colored body parts on two poisonous species
d. a poisonous species that resembles a harmless species
b
Characteristics that enable plants to protects themselves from herbivores include
a. sticky hairs and tough leaves
b. chemical defenses
c. thorns and prickles
d. all
d
Which of the following usually results when members of the same species require the same food and space?
a. competition
b. secondary succession
c. interspecific competition
d. primary succession
a
Competitive exclusion occurs when
a. new species enter an ecosystem
b. species reproduce
c. a species occupies a fundamental niche
d. a species is eliminated from a community because of competition
d
An ecologist studying an ocean ecosystem found that the removal of the sea stars from the ecosystem drastically affected it. In this ecosystem the sea stars were a
a. keystone species
b. competitive species
c. primary species
d. a species is eliminated from a community because of competition
c
The relationship between plants and bees that pollinate them is an example of what?
mutualism
The relationship between a whale and barnacles growing on its skin is an example of what?
commensalism
Species diversity is a measure of
a. the total number of individuals in a community
b. the number of plant species relative to the number of animal species in a community
c. the number of species and the relative abundance of each in a community
d. the number of species in a community
c
The closer an ecosystem is to the equator
a. the longer its growing season
b. the greater its diversity
c.the warmer its temperature
d. all
d
Extinction of many species of organisms is expected to occur in tropical areas becauuse of
a. global warming
b. destruction of habitats
c. people hunting many species of animals
d. predation by introduced animals
b
Which of the following is not a characteristic of a stable community?
a. goodresistance to insect pests
b. the ability to recover rapidly from a drought
c. a high species richness
d. a low number of predators
d
Succesion is
a. an organism's ability to survive in its envionment
b. the number of species living in an ecosystem
c. the regular progression of species replacement in an evniornment
d. the transfer of energy through a food chain
c
Which of the following types of succession would most liikely occur after a rain forest fire?
a. primary succession
b. secondary succession
c. old field succession
d. lake succession
b
Secondary succession occurs
a. as one generation of organisms replace the previous one
b. as a previously existing community is replaced
c. after a new food web is established
d. none
b
When the settlers arrived in New England, many forests were turned into fields. Eventually, some fields were abandoned and then grew back into forests. This is best described as
a. primary succession
b. coevolution
c. secondary succession
d. niche realization
c
Which of the following is not a characteristic of pioneer species?
a. they are small
b. the grow quickly
c. the reproduce slowly
d. they disperse many seeds
c
Common types of plants found in areas in the early stages of secondary succession are
a. shrubs
b. grasses
c. lichens
d. trees
b
In which interaction do both species benefit?
mutualism
Which of the following is true of a mimic?
a. it is poisonous or distasteful
b. it is identical to a poisonous species
c. it closely resembles a poisonous species
d. an example is the coral snake
c
Species richness
a. is greater on large islands than it is on small islands
b. is lowest in the tropics
c. is increasing worldwide
d. is greater on small islands than on large islands
a
Primary succession occurs
a. on bare rock
b. in a disrupted habitat
c. after a forest fire
d. only on dry land
a
A group of individuals of the same species living in the same place in the same time is a what?
population
A measure of how crowded a population is called the what?
population density
The distribution of individuals within the population is called the what?
dispersion pattern
A population's age structure is indicated by
a. the percentage of individuals at each age
b. limiting factors
c. dispersion pattern
d. inbreeding
a
The pattern of mortality that has devastating mortality early in life followed by low mortality for the remainder of the life span is what?
Type 3
The pattern of mortality that has low mortality until late in life is what?
Type 1
THe pattern of mortality that has constant mortality throughout life is what?
Type 2
Birth rate, death rate, immigration and emigration
a. create carrying capacity
b. are density dependent factors
c. determine whether a population will shrink or grow
d. are density independent factors
c
A population growth model that describes perpetual growth at an increasing rate is the what?
exponential model
The population growth model that assumes a constant birth and death rate and no immigration or emigration is the what?
exponential model
The population model that has the birth rate falling and the death rate climbing as the population growth is the what?
logistic model
The period of time in a logistic growth curve in which the birth and death rates are equal and the population is stable in size is the what?
carrying capacity
Enviornmental factors, which kill the same percentage of a populaton regardless of its size, are called what?
density-independent factors
Enviornmental factors that kill more individuals in large populations that in small ones are called what?
density-dependent factors
Small populations
a. are less able to rebound from envionmental changes
b. more likely to experience inbreeding
c. have low genetic diversity
d. all of these
d
The development of agriculture
a. caused the human population to become static
b. increased the growth rate of the human population
c. decreased the growth rate of the human population
d. resulted in inbreeding in the human population
b
Improvements in hygiene, diet, and economic conditions around 1650
a. caused the black plague
b. accelerated population decline
c. caused the human population to reach its carrying capacity
d. accelerated the population increase
d
The human population grew at its fastest rate in the decades
a. immediately after the World War 2
b. prior to world war 1
c. after the Korean war
d. after the gulf war
a
A clumped distribution
a. occurs when individuals are evenly spaced
b. may occur when resources are concentrated
c. occurs only because of social interactions between individuals
d. occurs only among plants
b
Life expectancy
a. refers to the maximum life span of an individual
b. is the average life span
c. depends only on birth rates
d. is the same for all species
b
Population growth
a. is a group of individuals of the same species living in the same place
b. is the spatial distribution of organisms in a population
c. is the change in the number of individuals in a population over a period of time
d. occurs only if all individuals in the population survive and reproduce
c
In the exponential model, the growth rate
a. is the same as the birth rate
b. is the change in population size after birth and death rates have been accounted for
c. changes with population size
d. is zero at the carrying capacity
c
According to the exponential model,
a. population growth stops at the carrying capacity
b. population growth increases and then decreases
c. the immigration rate falls with increasing population size
d. population growth continues indefinitely
d
Which of the following is not true of the carrying capacity in the logistic model?
a. varies with population size
b. remains constant
c. represesnts the maximum sustainable population
d. is the population size at which the birth rate eequals the death rate
d
Which if the following is not a density-independent factor for a population of deer in a forest?
a. a period of freezing weather
b. the number of cougars in the forest
c. a drought
d. a landslide
b
Inbreeding can be harmful to a population because it
a. increases the genetic variability of the population
b. increases the rate of evolution in the population
c. can increase mortality rate of offspring
d. decreases the carrying capacity
c
Organisms that manufacture organic nutrients for an ecosystem are called what?
primary producers
The primary producers in a grassland ecosystem would most likely be
a. insects
b. bacteria
c. grasses
d. algae
c
The organic material in an ecosystem is called
a. trophic level
b. biomass
c. energy level
d. ecomass
b
When an organism dies, the nitrogen in its body,
a. can never be reused by other living things
b. is immediately released into the atmosphere
c. is released by the action of decomposers
d. none
c
In a food web, which type of organism recieves energy from every other type?
a. producer
b. carnivore
c. decomposer
d. herbivore
c
Animals that feed on plants are at least in the
a. first trophic level
b. second trophic level
c. third trophic level
d. frouth trophic level
b
The number of trophic levels in an ecological pyramid
a. is limitless
b. is limited by the amount of energy that is lost at each trophic level
c. never exceeds four
d. never exceeds three
b
In goin from one trophic level to the next higher level
a. the number of organism increases
b. the amount of usable energy increases
c. the amount of usable energy decreases
d. diversity of organisms increases
c
Because energy diminishes at each successive trophic level, few ecosystems can contain more than
a. two trophic levels
b. four trophic levels
c. five trophic levels
d. eight trophic levels
b
Water and minerals needed by all organisms on Earth pass back and forth between the biotic and abiotic portions of the enviornment in a process known as what?
a biogeochemical cycle
Precipiation and evaporation are important components of the what?
water cycle
Which of the following is part of the nitrogen cycle?
a. conversion of atmospheric nitrogen into usable organic compounds by bacteria
b. conversion of nitrogen from decaying organisms into ammonia
c. nitrogen fixation
d. all
d
Nitrogen is a component of
a. proteins
b. fats
c. carbohydrates
d. water
a
In the nitrogen cycle, plants use nitrates and nitrites to form what?
amino acids
Coal, oil, and natural gas
a. are formed from decayed plants
b. are fossil fuels
c. release carbon dioxide when they are burned
d. all
d
Humans are affecting the carbon cycle by
a. burning fossil fuels
b. destroying vegetation that absorbs carbon dioxide
c. using electrical labor-saving devices
d. all
d
Major ecosystems that occur over wide areas of land are called what?
biomes
Which of the following biomes is characterized by evergreen trees and mammals such as moose, bears, and lynx?
a. taiga
b. polar
c. temperate rain forest
d. tundra
a
Herds of grazing animals are most likely to found in a
a. savanna
b. tropical rain forest
c. deciduous forest
d. taiga
a
The biome that makes up most of the central part of the U.S. is
a. rain forest
b. temperate grassland
c. tundra
d. deciduous forest
b
Which of the following is not an adaptation for water conservation found in desert organisms?
a. noctural lifestyle
b. deep root system
c. waxy leaf coatings
d. burrowing in the ground
b
The biome that makes up most of the central part of the U.S. is
a. rain forest
b. temperate grassland
c. tundra
d. deciduous forest
b
Which of the following animals would most likely be found in a temperate rain forest?
a. monkeys
b. carbiou
c. deer
d. leopards
c
Tropical ecosystems are more diverse than temperate zone ecosystems because
a. the growing season in tropical ecosystems never stops
b. the climate in tropical ecosystems does not vary much from year to year
c. a greater amount of food is produced in tropical ecosystems
d. all
d
Almost all of Earth's surface water is conatined in
a. ocean ecosystems
b. freshwater biomes
c. tropical rain forests
d. ponds and lakes
a
Plankton are
a. a major formation ingredient of most fossil fuels
b. found in the deep-water zone of most lakes and oceans
c. the base of most acquatic food webs
d. usually in the third and fourth trophic levels of ocean ecosystems
c
The greatest diversity of life in the ocean is found in
a. shallow ocean waters
b. the ocean surface
c. deep ocean waters
d. tidal areas
a
Which of the following processes harnesses energy for organisms living near deep-sea vents?
a. photosynthesis
b. hetertrophy
c. chemosynthesis
d. respiration
c
Eutrophic and oligotrophic lakes differ primarily in the amount of ____ they contain.
a. animal life
b. algae
c. salt
d. organic matter
d
Which of the following is not a viral disease of humans?
a. rabies
b. shingles
c. hepatitis
d. all
d
A resistant structure formed by some protozoa that enables them to survive harsh enviornmental conditions is an
a. eyespot
b. food vacuole
c. pseudopod
d. cyst
d
Bacteria lack a true nucleus and membrane-bound organelles; therefore they are classified as what?
prokaryotes
Bacteria are the only organisms characterized as
a. eukaryotic
b. photosynthetic
c. prokaryotic
d. unicellular
c
When tested with a Gram stain, gram-positive bacteria are stained
a. green
b. purple
c. pink
d. yellow
b
During the process of conjugation
a. two bacteria exchange DNA
b. a bacterial cell takes in DNA from the external envionment
c. one bacterium transfers DNA to another
d. a virus obtains DNA from a host bacterium
c
The study of viruses is a part of biology because
a. they are living organisms
b. they are active inside living cells
c. the are about to become extinct
d. they belong to the kingdom Eubacteria
b
The process in which two Paramecia come together after meiosis to exchange parts of their genetic material is called what?
conjugation
Giardiasis is a disease that is spread
a. by the Anopheles mosquito
b. by direct person-to-person contact
c. through the air
d. through water
d
Biologists now know that viruses
a. a. consists of a protien surrounded by a nucleic acid coat
b. are the smallest organisms
c. contain RNA or DNA in a protein coat
d. all form the same crystalline shape
c
Pseudopodia are used for
a. Paramecium conjugation
b. movement by amoebas
c. Paramecium mitosis
d. Euglena reproduction
b
Bacterial cells such as E. coli transfer pieces of genetic material in a process called what?
conjugation
All protozoa
a. use flagella to move
b. are parasites
c. have a true nucleus
d. move toward light
c
The capsid of a virus is the
a. protective outer coat
b. cell membrane
c. nucleus
d. cell wall and membrane complex
a
The protozoan that causes malaria reproduces in the
a. intestine of a human
b. stinger of a mosquito
c. red blood cells of a human
d. red blood cells of a mosquito
c
Which of the following are human diseases caused by protists?
a. leishmaniasis
b. amoebic dysentry
c. toxoplasmosis
d. all
d
Viruses that use reverse transcriptase to cause their host cells to transcribe DNA from an RNA template are called what?
retroviruses
Malaria is caused by
a. phytophtora
b. giardia
c. toxoplasma
d. plasmodium
d
Which of the following contains only a nucleic acid?
a. viroid
b. virus
c. prion
d. all
a
We know viruses are not alive because
a. they are not cellular
b. they cannot use energy
c. they cannot make proteins
d. all
d
One difference between human body cells and bacterial cells is that bacterial cells have
a. no ribosomes
b. an outer cell wall made up of phosphates
c. a cell wall made up of peptidoglycan
d. no DNA
c
Quinine
a. cures drug-resistant malaria
b. was produced in the 1980s using genetic engineering techniques
c. is derived from fungi
d. can be used to relieve the symptoms of malaria
d
A pathogen is an agent that is
a. nearly extinct
b. harmful to living organisms
c. harmful only to plants
d. beneficial to humans
b