How would you perform a reciprocal cross to test stem height in the garden pea?a. First cross is performed by transferring the pollen of a heterozygous tall plant to the stigma of a true breeding dwarf plant. Second cross is performed by transferring the pollen of a heterozygous dwarf plant to the stigma of a true breeding tall plant.b. First cross is performed by transferring the pollen of a true breeding tall plant to the stigma of a true breeding dwarf plant. Second cross is performed by transferring the pollen of a true breeding dwarf plant to the stigma of a true breeding tall plant.c. First cross is performed by transferring the pollen of a true breeding tall plant to the stigma of a heterozygous dwarf plant. Second cross is performed by transferring the pollen of a heterozygous dwarf plant to the stigma of a true breeding tall plant.d. First cross is performed by transferring the pollen of a heterozygous tall plant to the stigma of a heterozygous dwarf plant. Second cross is performed by transferring the pollen of a heterozygous tall plant to the stigma of a heterozygous dwarf plant.
b. First cross is performed by transferring the pollen of a true breeding tall plant to the stigma of a true breeding dwarf plant. Second cross is performed by transferring the pollen of a true breeding dwarf plant to the stigma of a true breeding tall plant.
A farmer raises black and white chickens. To his surprise, when the first generation of eggs hatch, all the chickens are black with white speckles throughout their feathers. What should the farmer expect from the eggs laid after interbreeding the speckled chickens?a. All the offspring will be speckled.b. 75% of the offspring will be speckled and 25% of the offspring will be black.c. 50% of the offspring will be speckled, 25% will be black, and 25% will be white.d. 50% of the offspring will be black and 50% of the offspring will be white.
c. 50% of the offspring will be speckled, 25% will be black, and 25% will be white.
In a mating between two individuals that are heterozygous for a recessive lethal allele that is expressed in utero, what genotypic ratio (homozygous dominant:heterozygous:homozygous recessive) would you expect to observe in the offspring?a. 1:2:1b. 3:1:1c. 1:2:0d. 0:2:1
c. 1:2:0
Use the probability method to calculate the genotypes and genotypic proportions of a cross between AABBCc and Aabbcc parents.a. Possible genotypes are AABBcc, AaBbCc, AaBbcc and the ratio 1 : 2 : 1. b. Possible genotypes are AABbcc, AaBbCc, AaBbcc and the ratio 1 : 3 : 1.c. Possible genotypes are AABbCc, AABbcc, AaBbCc, AaBbcc and the ratio 1 : 1 : 1 : 1.d. Possible genotypes are AABbcc, AaBbCC, AaBbcc and the ratio 1 : 1 : 1.
c. Possible genotypes are AABbCc, AABbcc, AaBbCc, AaBbcc and the ratio 1 : 1 : 1 : 1.
Which of the following genotypes is not possible for the offspring of the following cross?a. AaBBb. AaBbc. AABbd. none of these
c. AABb
In the shepherd's-purse plant (Capsella bursa-pastoris), seed shape is controlled by two genes, A and B. When both the A and B loci are homozygous recessive (aabb), the seeds are ovoid. However, if the dominant allele for either or both of these genes is present, the seeds are triangular. Based on this information, what are the expected phenotypic ratios for a cross between plants that are heterozygous for both traits?a. 12 tringular:4 ovoidb. 15 triangular:1 ovoidc. 10 triangular:6 ovoidd. 13 triangular:3 ovoid
...
Describe the structure and complementary base pairing of DNA.a. DNA is made up of two strands that are twisted around each other to form a helix. Adenine pairs up with thymine, and cytosine pairs with guanine. The two strands are anti-parallel in nature; that is, the 3' end of one strand faces the 5' end of other strand. Sugar, phosphate, and nitrogenous bases contribute to the DNA structure.b. DNA is made up of two strands that are twisted around each other to form a helix. Adenine pairs up with cytosine, and thymine pairs with guanine. The two strands are anti-parallel in nature; that is, the 3' end of one strand faces the 5' end of other strand. Sugar, phosphate, and nitrogenous bases contribute to the DNA structure.c. DNA is made up of two strands that are twisted around each other to form a helix. Adenine pairs up with thymine, and cytosine pairs with guanine. The two strands are parallel in nature; that is, the 3' end of one strand faces the 3' end of other strand. Sugar, phosphate, and nitrogenous bases contribute to the DNA structure.d. DNA is made up of two strands that are twisted around each other to form a helix. Adenine pairs up with thymine, and cytosine pairs with guanine. The two strands are anti-parallel in nature; that is, the 3' end of one strand faces the 5' end of other strand. Only sugar contributes to the DNA structure.
a. DNA is made up of two strands that are twisted around each other to form a helix. Adenine pairs up with thymine, and cytosine pairs with guanine. The two strands are anti-parallel in nature; that is, the 3' end of one strand faces the 5' end of other strand. Sugar, phosphate, and nitrogenous bases contribute to the DNA structure.
Which of the following is not one of the proteins involved during the formation of the replication fork?a. helicaseb. ligasec. origin of replicationd. single-strand binding proteins
a. helicase
What is the flow of information for the synthesis of proteins according to the central dogma?a. DNA to mRNA to proteinb. mRNA to protein to DNAc. DNA to protein to mRNAd. mRNA to DNA to protein
a. DNA to mRNA to protein
How long would the peptide be that is translated from this MRNA sequence: 5'-AUGGGCUACCGA-3'?a. 0b. 2c. 3d. 4
d. 4
What is a genetically modified organism (GMO)?a. a plant containing only wild type genesb. an organism with an artificially altered genomec. a hybrid organismd. any agricultural organism produced by breeding or biotechnology
b. an organism with an artificially altered genome
Which of the following situations will lead to natural selection?a. The seeds of two plants land near each other and one grows larger than the other.b. Two types of fish eat the same kind of food, and one is better able to gather food than the other.c. Male lions compete for the right to mate with females, with only one possible winner.d. All of the above.
d. All of the above.
What is the main difference between dispersal and vicariance?a. One leads to allopatric speciation, whereas the other leads to sympatric speciation.b. One involves the movement of the organism, and the other involves a change in the environment.c. One depends on a genetic mutation occurring, and the other does not.d. One involves closely related organisms, and the other involves only individuals of the same species.
b. One involves the movement of the organism, and the other involves a change in the environment.
When male lions reach sexual maturity, they leave their group in search of a new pride. This can alter the allele frequencies of the population through which of the following mechanisms?a. natural selectionb. genetic driftc. gene flowd. random mating
c. gene flow
The wing of a bird and the arm of a human are examples of ________.a. vestigial structuresb. molecular structuresc. homologous structuresd. analogous structures
c. homologous structures
Which of the following statements about analogous structures is true?a. They occur only as errors.b. They are synonymous with homologous traits.c. They are derived by similar environmental constraints.d. They are a form of mutation.
c. They are derived by similar environmental constraints.
Which of the following is not a common misconception about evolution?a. evolution is just a theory b. individuals evolvec. evolution explains the origin of lifed. populations evolve
d. populations evolve
Which of the following is not one of the six kingdoms?a. animaliab. plantaec. archaead. fungi
c. archaea
Which of the following methods will provide information to an ecologist about both the size and density of a population?a. mark and recaptureb. mark and releasec. quadratd. life table
c. quadrat
When the population size is unchanging, this is known as what type of growth?a. exponential growthb. zero population growthc. logistic growthd. s-shaped growth
b. zero population growth
An armadillo's outer shell is an example of what type of defense?a. mechanicalb. chemicalc. physical d. behavioral
a. mechanical
What factors have decreased the ability of infectious disease to limit human population growth in developed countries?a. public healthb. sanitation c. use of antibiotics and vaccinesd. all of these
...
The organisms that consume the producers are the...a. primary consumersb. secondary consumersc. tertiary consumersd. apex consumers
a. primary consumers
The majority of the water found on Earth is...a. ice b. water vaporc. fresh waterd. salt water
d. salt water
Carbon is stored for long periods in what are known as carbon reservoirs, which include the...a. atmosphereb. bodies of liquid waterc. ocean sedimentd. all of these
d. all of these
Why is the tundra treeless?a. lack of sufficient waterb. permanently frozen ground c. winters too harsh d. too many fires
b. permanently frozen ground
The deepest part of the ocean is the _________ zone, which is at depths of 4000 m or greater.a. intertidal b. neritic c. abyssald. none of these
c. abyssal
A key feature of estuaries is...a. low light conditions and high productivity b. saltwater and freshwater c. frequent algal bloomsd. little or no vegetation
b. saltwater and freshwater
Biodiversity increases closer to the ________.a. north poleb. south polec. equator d. prime meridian
c. equator
_____________, which are responsible for extraordinary improvements in health and lifespans in developed countries, are compounds largely derived from fungi and bacteria.a. Pesticides b. antibiotics c. agricultural soils d. toxins
b. antibiotics
Which two extinction risks may be a direct result of the pet trade?a. climate change and exotic species introductionb. habitat loss and overharvesting c. overharvesting and exotic species introduction d. habitat loss and climate change
c. overharvesting and exotic species introduction
Certain species of parrot cannot be brought to the United States to be sold as pets. What is the name of the legislation that makes this illegal?a. Red listb. migratory bird actc. CITESd. Endangered species act (ESA)
c. CITES
Imagine you are performing a cross involving seed color in garden pea plants. What F1 offspring would you expect if you cross true-breeding parents with green seeds and yellow seeds? Yellow seed color is dominant over green.a. 100 percent yellow-green seedsb. 100 percent yellow seedsc. 50 percent yellow, 50 percent green seedsd. 20 percent green, 75 percent yellow seeds
b. 100 percent yellow seeds
If the allele encoding polydactyly (six fingers) is dominant, why do most people have five fingers?a. Genetic elements suppress the polydactyl gene.b. Polydactyly is embryonic lethal.c. The sixth finger is removed at birth.d. The polydactyly allele is very rare in the human population.
d. The polydactyly allele is very rare in the human population.
If black and white true-breeding mice are mated and the result is all gray offspring, what inheritance pattern would this be indicative of?a. genetic mutationb. codominance c. sex-linkedd. incomplete dominance
d. incomplete dominance
How many offspring genotypes are expected in a trihybrid cross between parents heterozygous for all three traits when the traits behave in a dominant and recessive pattern? How many phenotypes?a. 64 genotypes; 16 phenotypesb. 16 genotypes; 64 phenotypesc. 8 genotypes; 27 phenotypesd. 27 genotypes; 8 phenotypes
d. 27 genotypes; 8 phenotypes
Assuming no gene linkage, in a dihybrid cross of AABB x aabb, what percentage of offspring will have the genotype AaBb?a. 100%b. 56.25%c. 18.75%d. 6.25%
a. 100%
A labrador retriever's fur color is controlled by two alleles, E and B. Any dog with the ee__ genotype develops into a yellow lab, while B_E_ dogs become black labs and bbE_ dogs become chocolate labs. This is an example of...a. epistasisb. codominance c. incomplete dominance d. linkage
...
What is the name of the method developed by Fred Sanger to sequence DNA?a. dideoxy chain termination methodb. double helix determinationc. polymerase chain reactiond. polymer gel electrophoresis
a. dideoxy chain termination method
Which enzyme initiates the splitting of the double DNA strand during replication?a. DNA gryaseb. helicasec. ligased. telomerase
b. helicase
The strand of DNA that is not used to transcribe mRNA is the...a. base strandb. lagging strandc. leading strandd. nontemplate strand
d. nontemplate strand
__________ is the process of decoding an mRNA message into a polypeptide product.a. replicationb. transcriptionc. translationd. duplication
c. translation
Which situation is most likely an example of convergent evolution?a. squid and humans have eyes similar in structureb. worms and snakes both move without legsc. some bats and birds have wings that allow them to flyd. all of the above
d. all of the above
Which reproductive combination produces hybrids?a. when individuals of the same species in different geographical areas reproduceb. when any two individuals sharing the same habitat reproducec. when members of closely related species reproduced. when offspring of the same parents reproduce
c. when members of closely related species reproduce
Population genetics is the study of...a. how selective forces change the allele frequencies in a population over time.b. the genetic basis of population-wide traits.c. whether traits have a genetic basis.d. the degree of inbreeding in a population.
a. how selective forces change the allele frequencies in a population over time.
What is true about organisms that are a part of the same clade?a. They all share the same basic characteristics.b. They evolved from a shared ancestor.c. They don't share homologous structures.d. They have identical phylogenies.
b. They evolved from a shared ancestor.
Human populations have which type of survivorship curve?a. type Ib. type IIc. type IIId. type IV
a. type I
An accelerating growth pattern seen in populations where resources are not limiting is known as...a. exponential growthb. zero population growthc. logistic growthd. s-shaped growth
a. exponential growth
What is the term used to describe the number of species living in a habitat or other unit?a. environmental disturbance b. relative species abundance c. island biogeography d. species richness
d. species richness
__________ ecosystems are the most common, comprising 75 percent of Earth's surface.a. marineb. freshwaterc. terrestriald. fungi
a. marine
_______________ is corrosive and caused by rainwater falling to the ground through sulfur dioxide gas, turning it into weak sulfuric acid.a. acid rainb. falloutc. hydrosphered. eutrophication
a. acid rain
Carbon is released as __________ when a volcano erupts, or from volcanic hydrothermal vents.a. carbon monoxideb. carbon tetrachloridec. carbon dioxided. all of these
c. carbon dioxide
__________ are the most diverse terrestrial biome.a. tropical rainforestsb. savannas c. temperate forestsd. boreal forests
a. tropical rainforests
Which of the following is not a type of biodiversity?a. geneticb. chemicalc. ecosystemd. habitat
d. habitat
The FDA approved five drugs based on animal toxins to treat diseases such as...a. hypertensionb. chronic painc. diabetesd. all of these
d. all of these
What kind of ecosystem are exotic species especially threatening to?a. desertsb. marine ecosystemsc. islandsd. tropical forests
c. islands
A scientist pollinates a true-breeding pea plant with violet, terminal flowers with pollen from a true-breeding pea plant with white, axial flowers. Which of the following observations would most accurately describe the F2 generation?a. 75% violet flowers; 75% terminal flowersb. 75% white flowers in a terminal positionc. 75% violet flowers; 75% axial flowersd. 75% violet flowers in an axial position
c. 75% violet flowers; 75% axial flowers
The observable traits expressed by an organism are described as its ________.a. phenotypeb. genotypec. allelesd. zygote
a. phenotype
In pea plants, purple flowers (P) are dominant to white flowers (p) and yellow peas (Y) are dominant to green peas (y). What genotype is not possible for a cross between PpYY and ppYy pea plants?a. PpYYb. PpYyc. ppYYd. PPYy
d. PPYy
When two genes are located in close proximity on the same chromosome, they are considered ________, and their alleles tend to be transmitted through meiosis together.a. groupedb. connectedc. linkedd. separated
c. linked
In eukaryotes, what is the DNA wrapped around?a. single-stranded binding proteinsb. sliding clampc. polymerased. histones
d. histones
The ends of the linear chromosomes are maintained by...a. helicaseb. primasec. DNA pold. Telomerase
d. Telomerase
Portions of eukaryotic mRNA sequence that are removed during RNA processing are ________.a. exonsb. capsc. poly-A tailsd. introns
d. introns
One of the three mRNA codons that specifies termination of translation is the...a. start codonb. exonc. nonsense codond. intron
c. nonsense codon
Manipulating the DNA of plants has helped to create desirable traits such as...a. disease resistanceb. pest resistancec. better nutritional valued. all of these
d. all of these
Which is an example of an adaptation?a. The better nutrition of a human helps her grow taller.b. The webbed feet of a duck helps it swim. c. The urban location of a raccoon helps it find food.d. An infectious microorganism is destroyed through the use of an antibiotic.
b. The webbed feet of a duck helps it swim.
Which condition is the basis for a species to be reproductively isolated from other members?a. It does not share its habitat with related species.b. It does not exist out of a single habitat.c. It does not exchange genetic information with other species.d. It does not undergo evolutionary changes for a significant period of time.
c. It does not exchange genetic information with other species.
Which of the following evolutionary forces can introduce new genetic variation into a population?a. natural selection and genetic driftb. mutation and gene flowc. natural selection and nonrandom matingd. mutation and genetic drift
b. mutation and gene flow
The theory of evolution describes...a. facts about the living worldb. ideas about the living worldc. views about the living worldd. beliefs about the living world
a. facts about the living world
Which statement about the taxonomic classification system is correct?a. There are more domains than kingdoms.b. Kingdoms are the top category of classification.c. A phylum may be represented in more than one kingdom.d. Species are the most specific category of classification.
d. Species are the most specific category of classification.
Which type of country has the greatest proportion of young individuals?a. countries that are economically developedb. countries that are economically underdevelopedc. countries with zero population growthd. countries in Europee. countries that are economically developed
b. countries that are economically underdeveloped
A ______________ is an area in lakes and oceans near the mouths of rivers where large areas are periodically depleted of their normal flora and fauna.a. dead zoneb. eutrophicationc. subductiond. non-renewable resource
a. dead zone
Which of the following biomes is characterized by short growing seasons?a. desertsb. tropical wet forestsc. arctic tundrad. savanna
c. arctic tundra
The _________ zone is the oceanic region that is closest to land.a. intertidalb. neriticc. abyssal d. none of these
a. intertidal
The number of currently described species on the planet is about ________.a. 17,000b. 150,000c. 1.5 million d. 10 million
c. 1.5 million