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194 Cards in this Set

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  • Back
Mendel had two pure lines of peas, one with wrinkled seeds, one with smooth seeds. He crossed these lines and found all smooth seeds in the F1 generation. Then, he crossed the F1 with each other. What did he find?
3:1 Smooth versus wrinkled seeds
Which of these statements does NOT fit Mendel’s model?
The male parent contributes the traits to the offspring.
The above pedigree displays the prevalence of hemophilia in a royal family. What was the genetic status of the parents of Irene, Fred, and Alix?
The father was normal, the mother a carrier.
What were the results of the experiment given above?
Only some males were white eyed.
A man and woman are both of normal pigmentation, but both have one parent who is albino (without melanin pigmentation). Albinism is an autosomal (not sex-linked) recessive trait. What is the probability that their first child will have albinism?
one fourth
A man who carries an X-linked allele (gene) will pass it on to
all of his daughters
Regarding an allelic pair for flower color in snapdragons, heterozygotes have pink flowers, whereas the two homozygotes have red flowers or white flowers. When plants with red flowers are crossed with plants with white flowers, what proportion of the offspring is expected to have pink flowers?
Pseudohypertrophic muscular dystrophy is a human disorder that causes gradual deterioration of the muscles. Only boys are affected, and they are always born to phenotypically normal parents. Due to the severity of the disease, the boys die in their teens. Is this disorder likely to be caused by a dominant or recessive allele? Is its inheritance sex-linked or autosomal?
recessive, sex-linked
A black guinea pig crossed with an albino guinea pig produced 12 black offspring. When the albino was crossed with a second black animal, 6 blacks and 6 albinos were obtained. What is the best explanation for this genetic situation?
Albino is recessive; black is dominant.
In rabbits, the homozygous CC is normal, Cc results in deformed legs, and cc results in very short legs. The genotype BB produces black fur, Bb brown fur, and bb white fur. If a cross is made between brown rabbits with deformed legs and white rabbits with deformed legs, what percentage of the offspring would be expected to have deformed legs and white fur?
Which strain(s) would you expect to kill mice when injected into their blood stream, if R is virulent and S is benign?
The R strain and R strain mixed with heat killed S strain
Which situation below would result in no transformation of a smooth strain to a rough
DNA eliminated, Proteins and RNA present
DNA replicates:
DNA replicates:
In the 3’ direction
Given the structure of DNA, what component of that structure is most directly associated with encoding genetic information?
nitrogenous bases and their sequence
Double-stranded nucleic acids are said to be antiparallel. What structural configuration is antiparallel?
The C-5’ to C-3’ ribose orientations run in opposite directions on the complementary strands.
In a sample of double-stranded DNA from a particular organism, if 15% of the nitrogenous base is thymine, what percentage should be cytosine?
She noted that there were not only some long strands but also numerous short segments of DNA a few hundred nucleotides long. What probably went wrong with the in vitro replication system she created?
Failure of DNA ligase occurred
Which of these processes does not involve DNA directly?
Which of these processes involves the expression of genes in a phenotype?
DNA is the information-coding component of cells. Of the following structures, which one is coded for by the longest sequence of DNA?
mRNA having 75 codons
Crick and co-workers found that when three base additions or three base deletions occurred in a single gene, the wild-type phenotype was sometimes restored
The code is triplet
When examining the genetic code, it is apparent that:
There can be more than one codon for a particular amino acid.
Given the pathway above, what therapy would you consider most likely to ameliorate (reduce) the symptoms associated with PKU if applied sufficiently early?
Reduce dietary intake of phenylalanine.
Which of the following mutations would have the greatest negative impact on the protein product of a gene?
a single base insertion near the start of the coding region of the gene
central dogma
1 = replication; 2 = transcription; 3 = translation
To begin transcription, the _____ binds to the –10 box and the –35 box, which are gene regions called:
sigma factor; promoters
In bacteria, transcription and translation occur ____, where in eukaryotes, these process occur ______.
Simultaneously; separately
Small ribonuclear proteins called snRNP’s, form _____ to remove ______ from the primary RNA transcript.
Spliceosomes, introns
If we radiolabel amino acids that are attached to tRNA, we would expect the level radioactivity on the tRNA to _____, as the level of radioactivity in proteins would ______.
Decrease; increase
When considering the general action of RNA polymerases in eukaryotes, all of the following macromolecules are transcribed directly from DNA except:
Select three posttranscriptional modifications often seen in the maturation of mRNA in eukaryotes.
5′-capping; 3′-poly(A) tail addition; splicing
Introns are known to contain stop codons (UAA, UGA, or UAG) yet not interrupt the
Stop codons within an intron are not involved in translation, because the introns are removed before translation
The -10 box has all the following characteristics except:
It is both transcribed and translated.
In contrast, when lacZ mutants are grown on medium containing X-Gal, the bacterial colonies remain their normal white color. What is X-Gal likely to be?
a compound chemically similar to lactose
What feature of the repressor protein accounts for the dyad symmetry of each operator of the lac operon?
The DNA binding domains of the repressor function as dimers.
Full induction of the lac operon occurs when:
lactose levels are high and glucose levels are low
Extracellular glucose inhibits transcription of the lac operon by:
reducing the levels of intracellular cAMP
The lysate of mutant A develops yellow color; the lysate of mutant B does not. What can you make of this?
Mutant A has a mutation in the lacY gene; mutant B has a mutation in the lacZ gene.
The lac operon is an example of _____ control, because if there is too much ____ the repressor changes shape so that it does not bind to the operator.
Post-translational: Lactose
Lactose only treatment
produces the most beta galactose
There are mutants on the lactose plate that are white until you break open the cell walls and spray the colonies with ONPG. What sort of mutants did you grow?
The primary difference between an enhancer and a promoter-proximal element is that:
Enhancers are at considerable distances from the promoter; promoterproximal elements are close to the promoter
One way to detect alternative splicing of a given gene is to:
compare the sequence of mature mRNAs made from this gene
Which of the following properties do you predict to be most critical to histone
Histones are positively charged
Not long ago, it was believed that a count of the number of genes in an organism would provide a count of the number of gene products. This is now known to be incorrect, largely due to the discovery of widespread:
alternative splicing
Fundamentally, what makes one cell different from another in a multicellular eukaryote?
The different cells contain different sets of regulatory proteins.
If the primary RNA transcript is not altered (i.e., no poly A tail or 5’ cap), this would be an example of:
Control via RNA processing
Which of these things happen first?
Histones become negatively charged
In the context of genetic engineering, plasmids are used as vectors. This means that plasmids allow for:
transfer of foreign genes into a cell
Which step in Southern blotting allows an investigator to identify a particular DNA fragment that is present within a complex mixture of fragments?
hybridization with a labeled probe
Imagine you’ve isolated, directly from the human genome, the complete gene that encodes human growth hormone. After running through all the steps for cloning and expression described in Section 19.1 of this chapter, you find no human growth hormone is expressed. Why do you think this procedure failed?
Bacteria cannot carry out splicing.
How does a gene library differ from a gene clone?
A gene library contains many different sequences; a gene clone contains one type of sequence.
Which of the following sequences is in the correct order for one cycle of PCR?
Denature DNA; anneal primers; extend primers.
Why is gel electrophoresis used in many procedures?
To separate pieces by size
What is the main reason gene therapy is not employed more often?
Viruses may insert genes randomly, causing cancer
Many crustaceans (e.g., lobsters, shrimp, and crayfish) use their tails to swim, but crabs have reduced tails that curl under their shells and are not used in swimming. This is an example of:
Radiometric dating is a technique used to determine the age of rocks. Geologists have used this technique to determine that:
Earth is about 4.6 billion years old, and life appeared on Earth about 3.8 billion years ago
Gill pouches in chick, human, and house-cat embryos are an example of:
developmental homology
The HOM genes of insects and the Hox genes of vertebrates are . . .
homologous because they are similar in organization, function and composition
A farmer uses triazine herbicide to control pigweed in his field. For the first few years, the triazine works well and almost all the pigweed dies; but after several years, the farmer sees more and more pigweed. Which of these explanations best describes this observation?
Only triazine-resistant weeds survived and reproduced, so each year more pigweed was triazine-resistant.
Recently, fossil dinosaurs have been found with feathers, indicating that they are _____ reptiles and birds.
A transitional form between
Antibiotic resistance occurs when:
resistant bacteria are the only survivors that reproduce.
Which of these statements is FALSE?
Tool use is subject to natural selection.
A biologist doing a long-term study on a wild spider population observes increased variation in silk thickness. She hypothesizes that the population is experiencing:
disruptive selection
The Dunkers are a religious group that moved from Germany to Pennsylvania in the mid-1700s. They do not marry with members outside their own immediate community. Today, the Dunkers are genetically unique and differ in gene frequencies, at many loci, from all other populations including their original homeland. Which of the following likely explains the genetic uniqueness of this population?
founder effect and genetic drift
Two frog populations (same species) living in two neighboring lakes sing slightly different courtship songs. Predict what likely happens to the songs of the two frog Females prefer loud frogs to quieter frogs, but do not distinguish between the two slightly different songs. Assume that courtship song differences have a genetic basis.
The songs become more similar to each other.
In Hardy Weinberg Terms, what variable represents the frequency of the recessive allele in the population?
Assume that blue eyes are recessive to brown eyes. What would be easier (take less time) to eliminate from a population?
Brown eyes
Several generations of inbreeding tend to ____ genetic variation.
Which of these is NOT part of Mendel’s model?
Alleles blend to form the offspring’s phenotype.
Mendel’s law of independent assortment states:
alleles separate into gametes in unique combinations of traits.
Which of these happens first in DNA replication?
The helicase unwinds the DNA.
DNA replicates in:
5’ to 3’
When we say that the genetic code is redundant, we mean:
that several codons code for the same amino acid.
DNA makes _____ that then makes _____.
RNA; protein
Which of these is TRUE?
Transcription and translation can occur at the same time in prokaryotes.
Given there are three “termination codons” that do not code for a given amino acid, you might expect there would be 61 tRNAs. But the actual number is smaller (about 40), because:
Some tRNAs have anticodons that can recognize two or more different codons.
What conditions fully induce the lac operon?
Low glucose; high lactose
Based on the above pedigree, what is the probability that Olga was a carrier for hemophilia (shaded = hemophilia)? Remember that hemophilia is a sex-linked, recessive trait.
Which components of the lac operon might you expect to see utilized in the regulation of other genes?
the CAP binding site
Histone bound DNA ___ be cut by DNases (DNA cutting enzymes).
One way to detect alternative splicing of a given gene is to:
compare the sequence of mature mRNAs made from this gene
PCR is similar to transcription in genes because both:
use primers to begin the reaction.
Why is a probe often radioactive?
To allow researchers to locate a gene
Researchers have found fossils of Eocene horse species in Colorado. Deeper deposits contain smaller species, and more recent deposits contain larger species. How does this observation support the theory of evolution?
It provides evidence that species change over time.
How old is the Earth, according to the fossil record?
over 4 billion years old
If taller males are more likely to find mates and have offspring, this would be a form of:
directional selection.
An earthquake decimates a ground-squirrel population. The surviving population happens to have broader stripes on average than the initial population. If broadness of stripes is genetically determined, what effect has the ground-squirrel population has experienced during the earthquake?
a genetic bottleneck
Which of the following statements explains why animals are less likely than plants to speciate by polyploidy?
Animals rarely self-fertilize, so diploid gametes are less likely to fuse.
What type of selection tends to result in speciation?
Disruptive selection
Male turkeys have a snood, which is a flap of skin that hangs across their beak. Snood length is negatively correlated with parasite load (e.g., males with longer snoods have fewer parasites), and females prefer to mate with long-snooded males. This is an example of:
sexual selection via female choice
HIV goes through a dormant stage, where the viruses do not replicate themselves using cell machinery. What type of reproduction does this correspond to?
The lysogenic cycle
Does treating a viral infection with antibiotics affect the course of the infection?
No; antibiotics do not kill viruses, because viruses use host proteins to replicate and antibiotics affect bacterial proteins.
What do Bacteria have in common with Archaea but not with Eukarya?
absence of nucleus
Bacteria and Archaea are very diverse and abundant groups. What allows them to occupy different habitats?
Metabolic diversity
Which of the following movements are matched correctly with the appendage that facilitates that movement in protists?
Swimming; flagella
Phytoplankton is comprised of photosynthetic protists and bacteria. For the most part, humans do not consume phytoplankton. Why, then, are they important to humans?
They are food for many marine organisms that humans eat.
Trees represent the:
sporophyte stage.
Which of these innovations allowed the growth of large land plants?
Vascular tissue
In ecological food webs, fungi tend to be:
Why are terrestrial fungal mycelium nearly always found within their food sources (underground, within wood, inside the bodies of dead organisms)?
Their high surface area, which is so efficient for absorptive feeding, makes them prone to drying out.
The sexually reproducing stage of a cnidarian (jellyfish) is a:
If you were diving in the ocean and found a sessile animal with spicules, you would be observing a:
After that, you saw an animal that was predatory with radial symmetry in the same ocean. You saw a/an:
sea star
Suppose all of the suspension feeders were removed from a lake. What would you expect to happen after some time?
The water would become murkier.
Which evolutionary innovation was most significant in helping tetrapods move to dry terrestrial environments?
the amniotic egg
In a terrestrial habitat that has undergone several consecutive years of drought, which animal population would you expect to be most negatively affected?
A scientist is studying the effect that building a dam would have on trout in the Colorado River. She is a/an:
population ecologist.
The dam in the question above would be a/an:
abiotic factor
Animal and plant diversity tends to __________ as latitude decreases.
In deep water, which of the following abiotic factors would most limit productivity?
light availability
Wetlands with the slowest water flow and the most acidic water are typically
Which of the following statements regarding temperate grasslands is false?
Grassland soils are not very fertile.
What is the main factor dictating Earth’s temperature distribution?
the amount of sunlight per unit area
Based on latitude, what should have the most humid climate?
An equatorial forest
If Earth were to reorient such that the North Pole always received direct sunlight (always faced the Sun), how would that change Earth’s climate?
The South Pole would get colder.
A fish swimming into an estuary from a river would have what great physiological challenge?
The change in water solute content would challenge the osmotic balance of the fish.
If we are wondering why a female lion allows her cubs to be killed when new males take over a pride, we are examining:
Ultimate causes
When an egg rolls out of a nest, a female goose performs a specific neck motion to bring the egg back into the nest, even if the egg is completely removed during the retrieval process. This behavior is:
A fixed action pattern
When the alarm clock goes off, Strawberry, my dog, runs to the back door because I usually let him out before I do anything else in the morning. Strawberry’s response to the alarm clock is:
classical conditioning
In testing his hypothesis that “territorial defense in European robins is a fixed action pattern that is released by the sight of orange feathers,” Lack found that robins defended their territory by attacking anything that was of similar size and had an orange patch. How would you show that it was indeed color that initiated the defense responses?
Repeat the experiment removing the orange patch.
The recognition and manipulation of facts about the world is termed
In red-winged blackbirds, which of the following stimuli elicited the greatest territorial defense response?
presenting both the model and playing the recording
Which would be the best way to obtain evidence of a bird’s cognitive abilities?
In captivity, have them attempt to solve novel problems.
What does Hamilton’s rule specify?
when alleles that favor self-sacrificing acts increase in frequency via kin selection
You observe scrub jays hiding food and notice that one particular individual only pretends to hide food. Your experiments associate the presence of other siblings with the frequency of pretending to cache food. A colleague shows you animals of the same species that do not perform this pretend caching. How does this affect your conclusions about this behavior?
It suggests that this behavior might be learned.
Which of these is NOT a population?
People of European descent in the U.S.
Females that lay ____ eggs tend to have ____ survivorship.
Few; high
When do density dependent factors begin to limit populations?
When populations reach the carrying capacity
What is the primary limiting factor that determines why no female animal can produce a very large number of very large eggs?
energy stores
The projections for Earth’s human population by 2050 made in 1992 are much higher than those recently made in 2002. What is the main difference recent history has made in this significant projection alteration?
Deaths from AIDS have significantly increased since 1992.
In an overpopulated area of deer, which of the following is a density-dependent factor that could help reduce the number of deer?
higher predation
Which of these is NOT a community?
People at UND
An example of an inducible defense would be:
Thicker shells in the presence of a predator
Removal of lynx from an environment caused a _____ in hare populations, indicating that the lynx was:
increase; keystone species
As the number of species in a plot ____, the productivity of that plot:
decreases; decreases
In biology, a coevolutionary arms race occurs when:
A pair of species influence each others’ evolution
Bees visit flowers to harvest nectar and pollen. What is the relationship between the bees and the flowers?
Which of the following is not a type of consumption?
A measure of how much a community is affected by a disturbance is termed
In terms of a lichen, which is a symbiotic organism containing algae and fungi, the algae is a:
Which of the following statements is FALSE?
Producers get energy from decomposers.
Which ecosystem is most productive on Earth?
Tropical wet forest
In the video, how did plants respond to increased carbon dioxide?
They grew faster and produced more leaves.
Which of the following do not consume other living organisms?
primary producers
Considering the global water cycle, where does one find the largest amount of water changing phases?
evaporation and precipitation over the oceans
Why are changes in the global carbon cycle important?
Carbon dioxide is a greenhouse gas, and increasing atmospheric concentrations could alter Earth’s climate.
Considering the current scientific literature on global warming, which statement best summarizes the most recent findings?
The Intergovernmental Panel on Climate Change concluded that current evidence suggests that most of the warming over the past 50 years is attributable to human activities.
In the case of lions, workers are seeking to preserve ______ by artificial insemination between lion prides
Genetic diversity
Which of these is considered to be an ecosystem service?
Carbon cycling
Which of the following statements regarding extinction is false?
Only certain species are immune from extinction.
Referring to the figure above, what antivenom would you administer to a person bitten by a King brown snake?
red-bellied black snake
The land developer offers 20 hectares in evenly distributed but isolated 1-hectare portions. The ecologists keep arguing for one 20 hectare area to remain intact. What’s the difference?
The isolated plots are more vulnerable to edge effects.
While traveling in the Alps, you come across a butterfly that you cannot identify. You quickly find out that it is a new species. Which of the following is not a step in understanding the biodiversity of this new species?
measuring general physiology of the species
What types of data suggest that Easter Island once had high biodiversity and productivity?
fossil pollen and animal bones
Which of the following does not tend to promote speciation?
gene flow
Male frogs give calls that attract female frogs to approach and mate. Researchers examined mating calls of pairs of closely related tree frogs in South America. If reinforcement of prezygotic isolation is occurring, what would you expect if you compare the calls of the two species in zones of sympatry and allopatry?
Calls would be more different in areas of sympatry.
Which of the following statements explains why animals are less likely than plants to speciate by polyploidy?
Animals rarely self-fertilize, so diploid gametes are much less likely to fuse.
Why is “reinforcement” an appropriate name for the concept that natural selection should favor divergence and genetic isolation if populations experience postzygotic isolation?
It reinforces selection for divergence that began when the species were geographically isolated
Two populations of birds with somewhat different coloration live on opposite sides of a peninsula. The habitat beween the populations is not suitable for these birds. When birds from the two populations are brought together, they produce young whose appearance is intermediate between the two parents. These offspring will breed with each other or with birds from either parent population, and all offspring of these pairings appear intermediate to various degrees. The two populations and the hybrids are:
different species, under the morphospecies concept
A researcher is examining fruit flies. She finds that some populations of fruit flies, though they look alike, are unable to produce offspring when they are mated in the lab. She concludes that these populations are different species. What species concept is she using?
the biological species concept
What sort of selection pattern tends to lead to speciation?
Disruptive selection
Which of the following statements applies to the lysogenic cycle?
The viral genome integrates into the host cell’s genome
Does treating a viral infection with antibiotics affect the course of the infection?
No; antibiotics do not kill viruses, because viruses use host proteins to replicate and antibiotics affect bacterial proteins.
To make a vaccine against the polio virus, researchers treated the polio virus with formaldehyde and used this preparation to inject people. This is an example of:
an inactivated virus vaccine
In doing gene therapy, researchers frequently use attenuated viruses to carry the normal gene into cells and replace the defective gene. Which type of virus is suited to this application?
lysogenic viruses
Emerging viruses are:
viruses that have recently switched from one host to a new host
Which of these statements is TRUE?
Viruses parasitize all living things
If an HIV molecule lacks integrase it will be unable to:
incorporate its DNA into the host genome.
While examining a rock surface, you have discovered an interesting new organism. Which of the following criteria will allow you to classify the organism as belonging to Bacteria but not Archaea or Eukarya?
Cell walls are made primarily of peptidoglycan.
Bacteria and Archaea are very diverse and abundant groups. What allows them to occupy different habitats?
Metabolic diversity
Cyanobacteria dominate many marine and freshwater environments. They became very numerous 2.7 billion years ago. Which of their features was responsible for such success?
ability to perform oxygenic photosynthesis
Which are evolutionarily more closely related?
Archaea and Eukarya
Gram positive bacteria lack a(n) _____ and stain _____.
Outer membrane; purple
A researcher thinks that they have found the bacterium that causes MRSA. He took a skin sample from a sick animal, and exposed a healthy animal to the sample. The healthy animal began to develop symptoms similar to the sick animal. What step did the researcher forget?
To isolate and grow the pathogen in a culture
Researchers interested in extraterrestrial life often study ____ because these organisms occur in extreme environments, and resemble early organisms.
Which of the following movements are matched correctly with the appendage that facilitates that movement in protists?
Swimming; flagella
If a protist has just generated a spore, what process has it just experienced?
Which of the following protists causes the human disease malaria?
Encouraging the growth (via nutrient fertilization) of photosynthetic protists in marine environments may help reduce global warming. Why?
Photosynthetic protists fix atmospheric carbon dioxide, decreasing carbon dioxide levels in the atmosphere.
Which of the following characteristics is true of all protists?
contains a nucleus
Which of these is NOT evidence for the endosymbiosis theory?
Some protists do not have chloroplasts
Red algae, which are photosynthetic, are most closely related to:
Which of the following is a correct element of alternation of generations?
The sporophyte is diploid and produces spores.
The vast number and variety of flowers is probably related to various kinds of:
An important fossil fuel is coal, much of which was formed when:
Extensive forests of seedless vascular plants were buried and compressed.
In what species would you expect to see swimming gametes in plants?
Microspores in Gymnosperms are the equivalent of:
pollen in angiosperms
Sugars made by one plant during photosynthesis can travel through a mycorrhizal fungus and be incorporated into the tissues of another plant
carbon-14 is found in the Douglas fir seedling's tissues and carbon-13 in the birch
Referring to Simard et al. (1997), what is the result that would most strongly refute Simard and colleagues hypothesis?
either carbon-13 or carbon-14 is found in the cedar seelding's tissues
In animals, why are fungal infections such as athlete's foot so much harder to cure than bacterial infections?
fungi and animals are more closely related than bacteria and animals.
Before karyogamy, what is the ploidy number of the gunal mycelium that has undergon plasomgamy
Lichen represent a relationship between two organisms. _____ allow(s) anchoring to the substrate; _____ provide(s) energy via photosynthesis
fungi; algae