22-31 Practice Questions

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Evolution works by _____.

"tinkering" with existing structures

Monophyletic

(of a group of organisms) descended from a common evolutionary ancestor or ancestral group, especially one not shared with any other group.

Systematists have used a wide variety of traits to reconstruct the phylogenies of particular groups of organisms. Which one of the following traits produces a good estimate of phylogeny?

- behavioral traits - molecular traits - biochemical traits - gross morphological traits

Spring has arrived, and you notice your neighbors are cutting their grass. When you walk outside to check if your mail has arrived, your eyes begin to water and feel itchy. You are more than likely experiencing

-- an overreaction to pollen. -- a pollen allergy

Because cytotoxic T cells can recognize viral proteins, they can destroy these infected cells. This is particularly important to individuals with certain kinds of cancers because

-- destroying the infected cells can help slow the spread of the infected cells . -- destroying the infected cells can help stop the spread of the infected cells.

Antigens can be

-- proteins. -- large polysaccharides that protrude from virus surfaces or foreign cells. -- blood or tissue cells from organisms of the same or different species.

If you were using cladistics to build a phylogenetic tree of cats, which of the following would be the best outgroup? -tiger -lion -wolf -domestic cat -leopard

-wolf

Traditionally, whales and hippopotamuses have been classified in different orders, the Cetacea and the Artiodactyla, respectively. Recent molecular evidence, however, indicates that the whales' closest living relatives are the hippos. This has caused some zoologists to lump the two orders together into a single clade, the Cetartiodactyla. There is no consensus on whether the Cetartiodactyla should be accorded order status or superorder status. This is because it remains unclear whether the whale lineage diverged from the lineage leading to the hippos before or after the other members of the order Artiodactyla (pigs, camels, etc.) diverged. If cetaceans are determined to have diverged from the lineage leading to the artiodactyls before the divergence of lineages leading to the modern artiodactyls (including hippos), then the cetaceans can be considered 1. a sister order to the order Artiodactyla. 2. an ingroup of the order Artiodactyla. 3. the common ancestor of the order Artiodactyla.

1 only

If the figure is an accurate depiction of relatedness, then which of the following should be correct? 1. The entire tree is based on maximum parsimony. 2. If all species depicted here make up a taxon, this taxon is monophyletic. 3. The last common ancestor of species B and C occurred more recently than the last common ancestor of species D and E. 4. Species A is the direct ancestor of both species B and species C. 5. The species present at position 3 is ancestral to C, D, and E.

1, 2, and 3

Rank the species from most closely related to horseflies to most distantly related to horseflies. If two species are equally close in their relatedness to horseflies, overlap them.

1. flea 2. katydid and human body louse 3. dragonfly and mayfly 4. silverfish

The age of fossils can sometimes be determined by radiometric dating, which is based on the constant rate of decay of radioactive isotopes. The time required for half of a radioactive isotope to decay is called the half-life of that isotope. For example, the isotope carbon-14 has a half-life of 5,730 years. Suppose it is determined that a fossilized leaf contains 12.5% of the carbon-14 that was present when the fossil formed. How old is the fossil? Express your answer numerically.

17,190

Consider the period from 2 million years ago to time 0. For lineage A, how many speciation and extinction events occurred from 2 million years ago to time 0?

2 speciation events and 5 extinctions

Given a population that contains genetic variation, what is the correct sequence of the following events, under the influence of natural selection? 1. Well-adapted individuals leave more offspring than do poorly adapted individuals. 2. A change occurs in the environment. 3. Genetic frequencies within the population change. 4. Poorly adapted individuals have decreased survivorship. - 4 → 1 → 2 → 3 - 4 → 2 → 3 → 1 - 4 → 2 → 1 → 3 - 2 → 4 → 3 → 1 - 2 → 4 → 1 → 3

2 → 4 → 1 → 3

Estimate the mean (average) persistence of species with nonplanktonic larvae.

2.2 million years

How many new species of snails with nonplanktonic larvae arose between 50 and 35 million years ago?

21 species

The Mesozoic era began approximately _____ million years ago.

251

The Precambrian time began at least _____ million years ago.

4,600

Estimate the mean (average) persistence of species with planktonic larvae.

4.4 million years

Earth probably formed _____ years ago, and the first life evolved as early as _____ years ago.

4.5 billion years ago ... 3.9 billion years ago

For lineage B, how many speciation and extinction events occurred from 2 million years ago to time 0?

5 speciation events and 1 extinction

How many new species of snails with planktonic larvae arose between 50 and 35 million years ago?

5 species

The Cenozoic era began approximately _____ million years ago.

A biologist studied a population of squirrels for 15 years. During that time, the population was never fewer than 30 squirrels and never more than 45. Her data showed that over half of the squirrels born did not survive to reproduce, because of both competition for food and predation. In a single generation, 90% of the squirrels that were born lived to reproduce, and the population increased to 80. Which inference(s) about this population might be true? - A. The amount of available food may have increased. - B. The parental generation of squirrels developed better eyesight due to improved diet; the subsequent squirrel generation inherited better eyesight. - C. The number of predators that prey upon squirrels may have decreased. - A and C could be true. - A, B, and C could be true.

A and C could be true.

soredia

A billionaire buys a sterile volcanic island that recently emerged from the sea. To speed the arrival of conditions necessary for plant growth, the billionaire might be advised to aerially sow what over the island? -soredia -yeasts -basidiospores -spores of ectomycorrhizae -leaves (as food for fungus-farming ants)

Homoplasy

A character shared by a set of species but not present in their common ancestor.

Basidiaomycota

A muchroom is a member of a group of fungi called the _______.

Which of the following is true? A. A single mosquito species can transmit more than one disease. B. It is unknown as to whether a single mosquito species can transmit more than one disease. C. A single mosquito species can transmit only one disease. D. Mosquitoes do not transmit diseases.

A single mosquito species can transmit more than one disease.

Which of the following statements about adaptive radiation is correct?

Adaptive radiation occurs within a single lineage.

The discovery of which of the following mosquitoes in Ohio would raise the most concern that Zika will soon be found there?

Aedes agypti

You study human evolution. In which of the following groups of people are you likely to find the least Neanderthal DNA?

Africans

Which of the following pieces of evidence most strongly supports the common origin of all life on Earth? - All organisms require energy. - All organisms have undergone evolution. - All organisms reproduce. - All organisms use essentially the same genetic code. - All organisms show heritable variation.

All organisms use essentially the same genetic code.

Which of these conditions should completely prevent the occurrence of evolution in a population over time? - The population lives in a habitat where there are no competing species present. - The environment is changing at a relatively slow rate. - All phenotypic variation between individuals is due only to environmental factors. - The population size is large.

All phenotypic variation between individuals is due only to environmental factors.

_____ were the dominant vertebrate life form during the Paleozoic era.

Amphibians

If you are allergic to grass pollen, that pollen is a(n) _____.

Antigen

The largest structure is the ascomycete, then the ascocarp, then the ascus, and finally the smallest is the ascospore.

Arrange the following from largest to smallest: 1. ascospore 2. ascocarp 3. ascomycete 4. ascus

According to this study, which of the following appears to be true?

As food scarcity increases, chimpanzee tool use for hunting increases.

Complement proteins can do all of the following except A. attack cancer and virus-infected cells after they are released by natural killer cells. B. help trigger the inflammatory response. C. enhance phagocytosis by innate immune cells by attaching to cell invaders. D. act as chemical signals to recruit more immune cells to the site of infection.

Attack cancer and virus-infected cells after they are released by natural killer cells.

Natural killer cells

Attack virus-infected cells by releasing chemicals that lead to cell death.

The body's innate defenses against infection include

Barriers such as dead skin cells and mucus

While hiking, you must push aside thick branches that are near your face. One of them rips the skin on your arm and you begin to bleed from the cut. Which of the following plays an important role in initially protecting you from infection? A. nonspecific antibodies B. memory cells because they are part of the adaptive immune system C. increased production of certain hormones and changes in microcirculation D. barriers such as dead skin cells and mucus because they are part of the innate immune system

Barriers such as dead skin cells and mucus because they are part of the innate immune system

________ rely completely on innate immunity.

Beetles

Which of the following pairs are the best examples of homologous structures?

Bones in the bat wing and bones in the human forelimb

The following question refers to the figure, which shows an outcrop of sedimentary rock whose strata are labeled A-D. If x indicates the location of fossils of two closely related species, then fossils of their most-recent common ancestor are most likely to occur in which stratum? A B C D

As the evolutionary biologist in charge of a student project to create a phylogenetic tree that better clarified the evolutionary relationships between the species listed in the accompanying figure, you asked the students to pose a question that would be a logical first step to better understand the evolutionary history of the group. Which student question would be the best starting point?

Can we evaluate evidence to determine the relationships of species D, E, and F?

We are living during the _____era.

Cenozoic

During a study session about evolution, one of your fellow students remarks, "The giraffe stretched its neck while reaching for higher leaves; its offspring inherited longer necks as a result." Which statement is most likely to be helpful in correcting this student's misconception? - If the giraffes did not have to compete with each other, longer necks would not have been passed on to the next generation. - Disuse of an organ may lead to its eventual disappearance. - Only favorable adaptations have survival value. - Characteristics acquired during an organism's life are generally not passed on through genes. - Spontaneous mutations can result in the appearance of new traits.

Characteristics acquired during an organism's life are generally not passed on through genes.

antibiotics

Chemicals, secreted by soil fungi, that inhibit the growth of bacteria are known as hallucinogens. -aflatoxins. -antibiotics. -antigens. -antibodies.

Which group of organisms (ciliates, animals, or plants) has the most complex cells?

Ciliates

Which of the following taxonomic categories contains all the others listed here? 1. Species 2. Family 3. Order 4. Genus 5. Class

Class

Which process is not an example of consumption?

Commensalism.

B) Sickle cell disease and malaria are both potentially lethal diseases. Though malaria is an infectious disease and sickle cell disease is inherited, both can cause life-threatening conditions.

Compare sickle cell disease and malaria. A) Sickle cell disease and malaria are both infectious diseases. B) Sickle cell disease and malaria are both potentially lethal diseases. C) Sickle cell disease and malaria are both genetic diseases. D) Sickle cell disease and malaria are both inherited diseases.

What are the three processes of genetic transfer in Bacteria?

Conjugation, transduction, and transformation

If organisms A, B, and C belong to the same class but to different orders and if organisms D, E, and F belong to the same order but to different families, which of the following pairs of organisms would be expected to show the greatest degree of structural homology?

D and F

Which of the following is an immediate effect of histamine release? A. dilation of local blood vessels B. conversion of histamine to histidine C. increase in blood pressure D. blocking of a response to ragweed pollen.

Dilation of local blood vessels

_____ were the dominant vertebrate life form during the Mesozoic era.

Dinosaurs

Which of the following statements regarding antigens and antibodies is false? A. Most antigens are proteins or large polysaccharides on the surfaces of viruses or foreign cells. B. An antibody usually recognizes and binds to an antigenic determinant. C. A single antigen may stimulate the immune system to make several distinct antibodies to it. D. Each antibody has only one antigen-binding site.

Each antibody has only one antigen-binding site.

A possible phylogenetic tree for the three domains of life. If the early history of life on Earth is accurately depicted by the figure, then which statement is least in agreement with the hypothesis proposed by this tree?

Eukaryotes are more closely related to archaeans than to bacteria.

If you were the evolutionary biologist in charge of a project to create a phylogenetic tree that better clarified the evolutionary relationships between the species listed in the accompanying figure, what would be a logical first step?

Evaluate evidence to determine the relationships of species D, E, and F.

The words "antigen" and "virus" are interchangeable.

False

True or false? The evolution of different ecomorphs on the Caribbean islands is an example of stabilizing selection.

False

96% of marine animal species became extinct in the Permian mass extinction at the end of the Paleozoic, 251 million years ago. Why does the blue curve show only a 50% drop at that time?

Families typically contain many species, so the percentage of families that became extinct is lower than the percentage of species that became extinct.

Which of the following discoveries would be most unusual?

Finding FOXP2 in Neanderthals and Denosivans.

B) No. The expected genotype frequencies are A1A1 0.553; A1A2 0.381; A2A2 0.066. The expected genotype frequencies are significantly different from those expected from the Hardy-Weinberg Principle.

For a gene suspected of causing hypertension in humans, you observe the following genotype frequencies: A1A1 0.574; A1A2 0.339; A2A2 0.087. Is this gene in Hardy-Weinberg equilibrium? Why or why not? (Assume that a difference of three percent or more in any of the observed versus expected frequencies is statistically significant.) A) No. The expected genotype frequencies are A1A1 0.553; A1A2 0.381; A2A2 0.166. B) No. The expected genotype frequencies are A1A1 0.553; A1A2 0.381; A2A2 0.066. C) Yes. The expected genotype frequencies are A1A1 0.574; A1A2 0.339; A2A2 0.087. D) Yes. The expected genotype frequencies are A1A1 0.553; A1A2 0.381; A2A2 0.066.

How can active immunity be obtained?

From a vaccine

Members of which kingdom have cell walls and are all heterotrophic?

Fungi

B) Refuse glucose

Glucose is generally phagostimulatory (stimulates eating) for animals. The observation that cockroach populations exposed to poison + glucose bait began to refuse to eat glucose brings up the question of whether this aversion behavior is learned or whether it originated as a genetic mutation that became more common in the population over generations. To answer this question, you can make use of some simple genetic crosses to look for predicted inheritance patterns. Only genetic traits, rather than learned behaviors, would be expected to show the predicted patterns. First, you need to find two populations of pure-breeding cockroaches: one population that has been exposed to poison + glucose bait and exhibits the glucose-aversion behavior one population that has not been exposed to poison + glucose bait and does not refuse to eat glucose (wild-type) Next you perform a hybrid cross in which you mate together members from each of the two populations to create F1 offspring. Hypothesis: Glucose aversion is a genetically-determined dominant trait Prediction: If true then the F1 offspring will ________. A) Have an intermediate amount of aversion B) Refuse glucose C) Eat glucose D) Have a mix of aversion and non-aversion

A) Have an intermediate amount of aversion

Glucose is generally phagostimulatory (stimulates eating) for animals. The observation that cockroach populations exposed to poison + glucose bait began to refuse to eat glucose brings up the question of whether this aversion behavior is learned or whether it originated as a genetic mutation that became more common in the population over generations. To answer this question, you can make use of some simple genetic crosses to look for predicted inheritance patterns. Only genetic traits, rather than learned behaviors, would be expected to show the predicted patterns. First, you need to find two populations of pure-breeding cockroaches: one population that has been exposed to poison + glucose bait and exhibits the glucose-aversion behavior one population that has not been exposed to poison + glucose bait and does not refuse to eat glucose (wild-type) Next you perform a hybrid cross in which you mate together members from each of the two populations to create F1 offspring. Hypothesis: Glucose aversion is a genetically-determined incompletely dominant trait Prediction: If true then the F1 offspring will ________. A) Have an intermediate amount of aversion B) Refuse glucose C) Eat glucose D) Have a mix of aversion and non-aversion

C) Eat glucose

Glucose is generally phagostimulatory (stimulates eating) for animals. The observation that cockroach populations exposed to poison + glucose bait began to refuse to eat glucose brings up the question of whether this aversion behavior is learned or whether it originated as a genetic mutation that became more common in the population over generations. To answer this question, you can make use of some simple genetic crosses to look for predicted inheritance patterns. Only genetic traits, rather than learned behaviors, would be expected to show the predicted patterns. First, you need to find two populations of pure-breeding cockroaches: one population that has been exposed to poison + glucose bait and exhibits the glucose-aversion behavior one population that has not been exposed to poison + glucose bait and does not refuse to eat glucose (wild-type) Next you perform a hybrid cross in which you mate together members from each of the two populations to create F1 offspring. Hypothesis: Glucose aversion is a genetically-determined recessive trait Prediction: If true then the F1 offspring will ________. A) Have an intermediate amount of aversion B) Refuse glucose C) Eat glucose D) Have a mix of aversion and non-aversion

D) Have a mix of aversion and non-aversion

Glucose is generally phagostimulatory (stimulates eating) for animals. The observation that cockroach populations exposed to poison + glucose bait began to refuse to eat glucose brings up the question of whether this aversion behavior is learned or whether it originated as a genetic mutation that became more common in the population over generations. To answer this question, you can make use of some simple genetic crosses to look for predicted inheritance patterns. Only genetic traits, rather than learned behaviors, would be expected to show the predicted patterns. First, you need to find two populations of pure-breeding cockroaches: one population that has been exposed to poison + glucose bait and exhibits the glucose-aversion behavior one population that has not been exposed to poison + glucose bait and does not refuse to eat glucose (wild-type) Next you perform a hybrid cross in which you mate together members from each of the two populations to create F1 offspring. Hypothesis: Glucose aversion is a learned behavior Prediction: If true then the F1 offspring will ________. A) Have an intermediate amount of aversion B) Refuse glucose C) Eat glucose D) Have a mix of aversion and non-aversion

A man who has been exposed to the flu virus is tested by his physician. The physician notes that the virus is present but no measurable level of antibodies corresponding to the virus are detected in his body. What might this mean?

He was probably exposed a few days ago and clonal selection has yet to produce plasma cells.

180

How can you determine if the glucose-aversion trait becomes more common in a cockroach population as a result of adaptive evolution? Part complete Exterminators have observed that their hydramethylnon-corn syrup baits initially work for attracting cockroaches, but the effectiveness lessens over time. Does this mean that the aversion trait evolves in the cockroach populations exposed to the bait? To answer this question, you need to identify a population of cockroaches with which you can perform an experiment. The experiment should be set up like this: 1. Observe and record the behavior of naïve cockroaches (never exposed to hydramethylnon) in a paired dish experiment using food with glucose and food without glucose. Record the number of cockroaches exhibiting the three phenotypes: glucose-attracted, intermediate, and glucose-averse. These represent the initial frequencies of wild type glu+ and mutant glu- alleles in the population. 2. Treat the cockroach population's environment with hydramethylnon + glucose bait for 5 years. 3. After 5 years (about 15 generations), observe and record exposed cockroach behavior in a paired dish experiment using food with glucose and food without glucose. Record the number of cockroaches exhibiting the three phenotypes: glucose-attracted, intermediate, and glucose-averse. 4. Determine if the population of cockroaches exposed to hydramethylnon + glucose is at Hardy-Weinberg equilibrium, or if exposure to hydramethylnon + glucose caused a shift in allele frequencies in the population. At the start of your experiment, suppose that you observed the genotypic distribution (based on phenotypic observations) shown in the table below in a naïve group of cockroaches in an infested apartment. The genotype (phenotype) is glu+/glu+ (glucose-attracted) There are 90 individuals in the original population. How many glu+ alleles are there?

How can you determine if the glucose-aversion trait becomes more common in a cockroach population as a result of adaptive evolution? Part complete Exterminators have observed that their hydramethylnon-corn syrup baits initially work for attracting cockroaches, but the effectiveness lessens over time. Does this mean that the aversion trait evolves in the cockroach populations exposed to the bait? To answer this question, you need to identify a population of cockroaches with which you can perform an experiment. The experiment should be set up like this: 1. Observe and record the behavior of naïve cockroaches (never exposed to hydramethylnon) in a paired dish experiment using food with glucose and food without glucose. Record the number of cockroaches exhibiting the three phenotypes: glucose-attracted, intermediate, and glucose-averse. These represent the initial frequencies of wild type glu+ and mutant glu- alleles in the population. 2. Treat the cockroach population's environment with hydramethylnon + glucose bait for 5 years. 3. After 5 years (about 15 generations), observe and record exposed cockroach behavior in a paired dish experiment using food with glucose and food without glucose. Record the number of cockroaches exhibiting the three phenotypes: glucose-attracted, intermediate, and glucose-averse. 4. Determine if the population of cockroaches exposed to hydramethylnon + glucose is at Hardy-Weinberg equilibrium, or if exposure to hydramethylnon + glucose caused a shift in allele frequencies in the population. At the start of your experiment, suppose that you observed the genotypic distribution (based on phenotypic observations) shown in the table below in a naïve group of cockroaches in an infested apartment. The genotype (phenotype) is glu+/glu- (intermediate) There are 7 individuals in the original population. How many glu+ alleles are there?

How can you determine if the glucose-aversion trait becomes more common in a cockroach population as a result of adaptive evolution? Part complete Exterminators have observed that their hydramethylnon-corn syrup baits initially work for attracting cockroaches, but the effectiveness lessens over time. Does this mean that the aversion trait evolves in the cockroach populations exposed to the bait? To answer this question, you need to identify a population of cockroaches with which you can perform an experiment. The experiment should be set up like this: 1. Observe and record the behavior of naïve cockroaches (never exposed to hydramethylnon) in a paired dish experiment using food with glucose and food without glucose. Record the number of cockroaches exhibiting the three phenotypes: glucose-attracted, intermediate, and glucose-averse. These represent the initial frequencies of wild type glu+ and mutant glu- alleles in the population. 2. Treat the cockroach population's environment with hydramethylnon + glucose bait for 5 years. 3. After 5 years (about 15 generations), observe and record exposed cockroach behavior in a paired dish experiment using food with glucose and food without glucose. Record the number of cockroaches exhibiting the three phenotypes: glucose-attracted, intermediate, and glucose-averse. 4. Determine if the population of cockroaches exposed to hydramethylnon + glucose is at Hardy-Weinberg equilibrium, or if exposure to hydramethylnon + glucose caused a shift in allele frequencies in the population. At the start of your experiment, suppose that you observed the genotypic distribution (based on phenotypic observations) shown in the table below in a naïve group of cockroaches in an infested apartment. The genotype (phenotype) is glu-/glu- (glucose-averse) There are 3 individuals in the original population. How many glu+ alleles are there?

187

How can you determine if the glucose-aversion trait becomes more common in a cockroach population as a result of adaptive evolution? Part complete Exterminators have observed that their hydramethylnon-corn syrup baits initially work for attracting cockroaches, but the effectiveness lessens over time. Does this mean that the aversion trait evolves in the cockroach populations exposed to the bait? To answer this question, you need to identify a population of cockroaches with which you can perform an experiment. The experiment should be set up like this: 1. Observe and record the behavior of naïve cockroaches (never exposed to hydramethylnon) in a paired dish experiment using food with glucose and food without glucose. Record the number of cockroaches exhibiting the three phenotypes: glucose-attracted, intermediate, and glucose-averse. These represent the initial frequencies of wild type glu+ and mutant glu- alleles in the population. 2. Treat the cockroach population's environment with hydramethylnon + glucose bait for 5 years. 3. After 5 years (about 15 generations), observe and record exposed cockroach behavior in a paired dish experiment using food with glucose and food without glucose. Record the number of cockroaches exhibiting the three phenotypes: glucose-attracted, intermediate, and glucose-averse. 4. Determine if the population of cockroaches exposed to hydramethylnon + glucose is at Hardy-Weinberg equilibrium, or if exposure to hydramethylnon + glucose caused a shift in allele frequencies in the population. At the start of your experiment, suppose that you observed the genotypic distribution (based on phenotypic observations) shown in the table below in a naïve group of cockroaches in an infested apartment. There are 100 individuals in the original population. How many glu+ alleles are there?

p=0.94, The sum total of all alleles in a population is known as its gene pool, and the allele frequency is a measure of the proportion of each allele in the gene pool.

A) He evaluated blood samples for malaria parasites and the presence of sickle cells. D) He expanded his study area beyond Kenya to the rest of East Africa to see if malaria and sickle disease were connected. Dr. Allison gathered blood samples from more than 5,000 children in East Africa. He analyzed the samples to identify malaria parasites and sickle cells. He found that children carrying the sickle cell character (or trait) had a lower parasite count, as if they were partially protected against malaria.

How did Dr. Allison test his hypothesis that sickle cell disease was connected to malaria? Select all that apply. A) He evaluated blood samples for malaria parasites and the presence of sickle cells. B) He looked for the underlying genetic mechanism causing sickle cell disease. C) He studied the way that the malaria parasite interacts with sickle cells. D) He expanded his study area beyond Kenya to the rest of East Africa to see if malaria and sickle disease were connected.

B) In areas with malaria, individuals with one sickle cell allele reproduced at higher rates than those with no sickle cell alleles. C) In areas without malaria, individuals with two sickle cell alleles reproduced at lower rates than those without sickle cell disease. In different environments, natural selection favors different characteristics. In areas with malaria, the reproductive advantages of having one sickle cell allele (and some protection from malaria) kept the allele at high frequencies in the population. In areas without malaria, the reproductive disadvantages from sickle cell disease reduced the allele in populations.

How does Dr. Allison's work provide an example of natural selection in humans? Select all that apply. A) Natural selection caused the sickle cell allele to appear in east African populations. B) In areas with malaria, individuals with one sickle cell allele reproduced at higher rates than those with no sickle cell alleles. C) In areas without malaria, individuals with two sickle cell alleles reproduced at lower rates than those without sickle cell disease. D) In areas with malaria, natural selection causes individuals to acquire the sickle cell allele as protection against malaria.

B) Homozygotes increase in frequency in the population over generations. Inbreeding increases homozygosity.

How does inbreeding alter genotype and allele frequencies? A) Dominant alleles become less prevalent in the population over generations. B) Homozygotes increase in frequency in the population over generations. C) Heterozygotes increase in frequency in the population over generations. D) There is no change in genotype frequency.

A) It increases genetic diversity by introducing alleles from one population into another. Gene flow is the movement of alleles between populations.

How might gene flow be important in managing an endangered population? A) It increases genetic diversity by introducing alleles from one population into another. B) It is not important to managing an endangered species. C) It increases genetic diversity by introducing new genes into the DNA of a population. D) It decreases genetic diversity via the loss of alleles due to inbreeding depression.

A) The person is homozygous at the hemoglobin locus. C) The person is susceptible to malaria. A person with two copies of any allele is homozygous. A person with two normal copies of the hemoglobin allele is more susceptible to malaria than someone with a sickle cell hemoglobin allele.

If a person has two normal copies of the hemoglobin allele, which statements are true? Select all that apply. A) The person is homozygous at the hemoglobin locus. B) The person is heterozygous at the hemoglobin locus. C) The person is susceptible to malaria. D) The person is protected against malaria.

If Darwin had been aware of genes, and of their typical mode of transmission to subsequent generations, with which statement would he most likely have been in agreement? - If an individual's somatic cell genes change during its lifetime, making it more fit, then it will be able to pass these genes on to its offspring. - If an individual acquires new genes by engulfing, or being infected by, another organism, then a new genetic species will be the result. - A single mutation in a single gene in a single gamete will, if perpetuated, produce a new species within just two generations. - If natural selection can change one gene's frequency in a population over the course of generations then, given enough time and enough genes, natural selection can cause sufficient genetic change to produce new species from old ones.

If natural selection can change one gene's frequency in a population over the course of generations then, given enough time and enough genes, natural selection can cause sufficient genetic change to produce new species from old ones.

A) Support. Because the observed number of glucose-averse roaches is much higher than expected, you can conclude that the population is not in Hardy-Weinberg equilibrium. Therefore, the population must be evolving with regard to this trait. To make a more solid conclusion, you would do a statistical analysis to make sure the observed values were different enough from the expected values that they would not be due to chance alone.

If natural selection for this trait is not occurring, you would expect to see about the same genotype frequencies in all generations of the cockroaches. Below is a table of genotypes observed in 455 individuals after 5 years of exposure to hydramethylnon + glucose bait compared to those expected from predicted allele frequencies. If the observed values do not approximately match the expected values, then you have evidence that the population is going through adaptive evolution. What conclusion can you draw from these data? The data _______ the conclusion that the glucose-aversion trait has become more common in the population as a result of adaptive evolution A) Support B) Do not support

B) Much higher than. Because the observed number of glucose-averse roaches is much higher than expected, you can conclude that the population is not in Hardy-Weinberg equilibrium. Therefore, the population must be evolving with regard to this trait. To make a more solid conclusion, you would do a statistical analysis to make sure the observed values were different enough from the expected values that they would not be due to chance alone.

If natural selection for this trait is not occurring, you would expect to see about the same genotype frequencies in all generations of the cockroaches. Below is a table of genotypes observed in 455 individuals after 5 years of exposure to hydramethylnon + glucose bait compared to those expected from predicted allele frequencies. If the observed values do not approximately match the expected values, then you have evidence that the population is going through adaptive evolution. What conclusion can you draw from these data? The observed number of glucose-averse cockroaches is_________ than expected. A) Much lower than B) Much higher than

D) He hypothesized that there was a connection between malaria and sickle cell disease. On the basis of this hypothesis, Dr. Allison predicted high frequencies of sickle cell disease only in areas where malaria is common.

In 1949, Dr. Tony Allison observed a high frequency of Kenyans carrying the sickle cell allele in coastal areas and near Lake Victoria, but a lower frequency in the highlands. What did he hypothesize? A) He hypothesized that malaria causes sickle cell disease. B) He hypothesized that sickle cell disease was an environmental, not a genetic disease. C) He hypothesized that malaria is a genetic disease. D) He hypothesized that there was a connection between malaria and sickle cell disease.

What is the key difference between active immunity and passive immunity?

In active immunity, a body produces its own antibodies; in passive immunity, a person receives pre-made antibodies.

water and minerals

In both lichens and mycorrhizae, what does the fungal partner provide to its photosynthetic partner?

A) Individuals with one sickle cell allele are protected from malaria and do not have sickle cell disease, thus keeping the allele in the population. People with one sickle cell allele are protected from malaria, but do not have sickle cell disease. Protection from malaria comes at the cost of more sickle cell disease in the population.

In some populations, 1 in 500 people have sickle cell disease. What reason does the film give for why a potentially deadly, inherited disease is found at such high frequencies? A) Individuals with one sickle cell allele are protected from malaria and do not have sickle cell disease, thus keeping the allele in the population. B) Individuals with two sickle cell alleles have an evolutionary advantage because they do not get sickle cell disease or get infected with malaria. C) Sickle cell alleles are new mutations and not enough time has gone by for these alleles to be eliminated from the population by natural selection. D) Individuals with two normal hemoglobin alleles get both sickle cell disease and are susceptible to malaria, so these alleles are eliminated from the population. Submit

A) 136, 65, 0.5 B) 118. 116, 1.0 C) 14, 92, 6.6 Notice how the relative fitness values change based on the type of food offered to the cockroaches in each treatment. Next you will use these relative fitness values to predict which genotypes will thrive under different conditions.

In the presence of poison-laced glucose, cockroaches that refuse glucose will have a much higher survival rate than cockroaches that feed indiscriminately. This explains why the glu- allele frequency increases over time in a population exposed to poison + glucose bait. However, energy from carbohydrates is required for growth and reproduction, and glucose is commonly found in non-poison foods that cockroaches encounter in human dwellings. By refusing to eat glucose, are glu-/glu- roaches missing out on an essential energy source? One way to answer this question is to measure the relative fitness of glu-/glu- roaches. Relative fitness is the contribution an individual makes to the gene pool of the next generation relative to the contribution of other individuals. Relative fitness is affected by diet and environmental hazards. To determine the relative fitness of a particular genotype, you average the fitness values of a group of individuals with that genotype. Suppose you raise populations of each homozygous genotype in captivity with three different food sources (plus supplemental rat chow) and collect data about how many individuals survive from egg to adulthood (survivorship) and how many offspring each adult female produces over her lifetime (fecundity). The survivorship and fecundity data are shown in the table below. From this data, you can calculate fitness values. The absolute fitness of each genotype is calculated by multiplying the survivorship by the fecundity (only those individuals that survive will reproduce). The fitness of one relative to the other is the ratio of the two absolute fitness values. Use the following data to complete the table of fitness calculations. Convert percentage values to decimals before you do the calculations. Round absolute fitness values to the nearest whole number; round relative fitness values to one decimal place. The absolute fitness of glu+/glu+ (survivorship x fecundity), absolute fitness of glu-/glu- (survivorship x fecundity), and relative fitness of glu-/glu- to glu+/glu+ A) Food containing glucose, B) Food lacking glucose C) Hydramethylnon + corn syrup traps

Virus-infected cells produce ________, proteins that help neighboring cells fight further viral infections.

Interferons

Traditionally, whales and hippopotamuses have been classified in different orders, the Cetacea and the Artiodactyla, respectively. Recent molecular evidence, however, indicates that the whales' closest living relatives are the hippos. This has caused some zoologists to lump the two orders together into a single clade, the Cetartiodactyla. There is no consensus on whether the Cetartiodactyla should be accorded order status or superorder status. This is because it remains unclear whether the whale lineage diverged from the lineage leading to the hippos before or after the other members of the order Artiodactyla (pigs, camels, etc.) diverged. If it turns out that the whale lineage diverged from the lineage leading to hippos after the divergence of the lineage leading to the pigs and other artiodactyls, and if the whales continue to be classified in the order Cetacea, then what becomes true of the taxon Cetartiodactyla?

It should be considered as one monophyletic superorder.

cyanobacteria and green algae.

Lichens are symbiotic associations of fungi and _____ and _____.

Most _________ are located at specific areas where bacteria microbes tend to attack so that they can readily engulf and destroy the invading bacteria.

Macrophages

Which of the following statements regarding the cell-mediated response is correct? A. Both B and T cells are responsible for the cell-mediated response. B. The self proteins bind to and present the antigens to the cell so that macrophages can ingest them. C. Macrophages digest the antigen to break it up into its components, which are then bound by and presented to the cell surface for removal. D. Cells may clump around viruses to render the virus inactive.

Macrophages digest the antigen to break it up into its components, which are then bound by and presented to the cell surface for removal.

When it comes to chimpanzees, which of the following is true?

Males catch most of the prey.

Which organisms are not examples of an adaptive radiation?

Mammals and reptiles in the post-dinosaur age

Dinosaurs went extinct during the _____.

Mesozoic

Flowering plants first appeared during the _____.

Mesozoic

If current research proves correct, which of the following will be true?

Modern human ancestors interbred with Neanderthals three times.

What kind of evidence has recently made it necessary to assign the prokaryotes to either of two different domains, rather than assigning all prokaryotes to the same kingdom?

Molecular

________ are a component of the immune system that are able to destroy cancer cells by deploying toxins into infected cells as a means of killing them. In this role they are cytotoxic - that is, "cell killing."

Natural killer cells

The upper forelimbs of humans and bats have fairly similar skeletal structures, whereas the corresponding bones in whales have very different shapes and proportions. However, genetic data suggest that all three kinds of organisms diverged from a common ancestor at about the same time. Which of the following is the most likely explanation for these data? - Forelimb evolution was adaptive in people and bats, but not in whales. - Humans and bats evolved by natural selection, and whales evolved by Lamarckian mechanisms. - Whales are not properly classified as mammals. - Genes mutate faster in whales than in humans or bats. - Natural selection in an aquatic environment resulted in significant changes to whale forelimb anatomy.

Natural selection in an aquatic environment resulted in significant changes to whale forelimb anatomy.

You are an anthropologist and wish to continue the studies of DNA lineage of Denisovans. Which of the following places would likely be best for you to collect new samples from currently living humans?

New Guinea

DDT was once considered a "silver bullet" that would permanently eradicate insect pests. Today, instead, DDT is largely useless against many insects. Which of these would have been required for this pest eradication effort to be successful in the long run? - The frequency of DDT application should have been higher. - DDT application should have been continual. - All habitats should have received applications of DDT at about the same time. - None of the individual insects should have possessed genomes that made them resistant to DDT. - Larger doses of DDT should have been applied.

None of the individual insects should have possessed genomes that made them resistant to DDT.

A large proportion of archaeans are extremophiles, so called because they inhabit extreme environments with high acidity, salinity, and/or temperature. Such environments are thought to have been much more common on the primitive Earth. Thus, modern extremophiles survive only in places that their ancestors became adapted to long ago. Which of the following is, consequently, a valid statement about modern extremophiles, assuming that their habitats have remained relatively unchanged?

On a phylogenetic tree whose branch lengths are proportional to the amount of genetic change, the branches of the extremophiles should be shorter than the non-extremophilic archaeans.

Bony fish first evolved during the _____ .

Paleozoic

Most modern animal phyla evolved during the _____ era.

Paleozoic

Reptiles first appeared during the _____ era.

Paleozoic

Seed plants first appeared during the _____.

Paleozoic

The transfer of antibodies in breast milk to an infant is an example of ________ immunity.

Passive

Macrophages and neutrophils defend against pathogens by _____.

Phagocytizing pathogens

Select the correct statement about photosynthesis by primary producers.

Photosynthetic protists and prokaryotes carry out the majority of the photosynthesis in aquatic communities.

Select the correct statement about phylogenetic trees.

Phylogenetic trees may expand quickly to maximum width and then narrow over time.

Which of the following can initiate an inflammatory response? A. physical injury such as a cut B. antibodies C. adrenaline D. a deficiency in histamine

Physical injury such as a cut

Which of the following is not an observation or inference on which natural selection is based? - Only a fraction of an individual's offspring may survive. - Poorly adapted individuals never produce offspring. - Species produce more offspring than the environment can support. - Individuals whose characteristics are best suited to the environment generally leave more offspring than those whose characteristics are less well suited. - There is heritable variation among individuals.

Poorly adapted individuals never produce offspring.

Animals first appeared during the _____.

Precambrian

Life arose during the _____.

Precambrian

The first prokaryotic cells appeared during the _____.

Precambrian

A) The sickle cell allele will decrease in frequency. Without malaria, selection for the sickle cell allele decreases. As a result, the frequency will likely decrease.

Predict what will happen to the frequency of the sickle cell allele in areas where malaria has been eradicated. A) The sickle cell allele will decrease in frequency. B) The sickle cell allele frequency will not be affected. C) The sickle cell allele will increase in frequency.

Antibodies are

Proteins

Why do some scientists believe that RNA, rather than DNA, was the first genetic material?

RNA has both information storage and catalytic properties.

Logically, which of these should cast the most doubt on the relationships depicted by an evolutionary tree? - The skeletal remains of the organisms depicted by the tree were incomplete (in other words, some bones were missing). - Relationships between DNA sequences among the species did not match relationships between skeletal patterns. - Some of the organisms depicted by the tree had lived in different habitats. - None of the organisms depicted by the tree ate the same foods. - Transitional fossils had not been found.

Relationships between DNA sequences among the species did not match relationships between skeletal patterns.

Your uncle is a paleontologist. Where is he most likely to find Denosivan fossils?

Siberia

Select a plausible hypothesis to explain the difference in mean persistence of snail species with planktonic and nonplanktonic larvae.

Snails with nonplanktonic larvae have more limited distributions than snails with planktonic larvae.

Within six months of effectively using methicillin to treat S. aureus infections in a community, all new infections were caused by MRSA. How can this result best be explained? - A patient must have become infected with MRSA from another community. - S. aureus can resist vaccines. - The drug caused the S. aureus DNA to change. - In response to the drug, S. aureus began making drug--resistant versions of the protein targeted by the drug. - Some drug-resistant bacteria were present at the start of treatment, and natural selection increased their frequency.

Some drug-resistant bacteria were present at the start of treatment, and natural selection increased their frequency.

Currently, two extant elephant species (X and Y) are placed in the genus Loxodonta, and a third species (Z) is placed in the genus Elephas. Thus, which statement should be true? - Species X and Y are the result of artificial selection from an ancestral species Z. - Species X and Y share a common ancestor that is still extant (in other words, not yet extinct). - Species X and Y are not related to species Z. - Species X and Y share a greater number of homologies with each other than either does with species Z. - Species X, Y, and Z share a common ancestor, but nothing more can be claimed than this.

Species X and Y share a greater number of homologies with each other than either does with species Z.

What was the main selective pressure behind the evolution of different Anolis lizard species in the Caribbean?

Specific ecological niches

Which of the following is a lymphatic organ? A. blood B. interstitial fluid C. thymus D. spleen

Spleen

In 1959, doctors began using the powerful antibiotic methicillin to treat infections of Staphylococcus aureus, but within two years, methicillin-resistant strains of S. aureus (MRSA) appeared. How did the resistant strains of S. aureus emerge? - In response to treatment of Staphylococcus aureus infections with methicillin, some bacteria began to synthesize cell walls using a protein that was not affected by methicillin. These bacteria survived the methicillin treatments and reproduced at higher rates than did other individuals. Over time, these resistant individuals became increasingly common. - Staphylococcus aureus bacteria that were able to synthesize cell walls using a protein that was not affected by methicillin survived the methicillin treatments and reproduced at higher rates than did other individuals. Over time, these resistant individuals became increasingly common. - In response to treatment of Staphylococcus aureus infections with methicillin, bacterial populations gradually began to synthesize cell walls using a protein that was not affected by methicillin.

Staphylococcus aureus bacteria that were able to synthesize cell walls using a protein that was not affected by methicillin survived the methicillin treatments and reproduced at higher rates than did other individuals. Over time, these resistant individuals became increasingly common. (Evolutionary change comes about as the proportion of individuals in the population displaying a particular trait increases from generation to generation.)

A) glu-/glu- (glucose-averse) B) glu+/glu+ (glucose-attracted) C) glu-/glu- (glucose-averse) D) It's a tie - no winner As you have seen, the genotype with the greatest fitness depends on the environmental conditions. And as environmental conditions change, the allele frequencies and genotype frequencies in the population will fluctuate. This is the essence of adaptive evolution, not only in cockroaches but in every population of living things.

Suppose a large apartment complex is infested with cockroaches that have never been exposed to glucose-baited poison. A new tenant moves in and unknowingly brings along some stowaway glucose-averse cockroaches from her heavily-treated former apartment. These individuals escape the moving boxes and start reproducing in their new home, where they have to compete with the current resident cockroaches. Using the fitness values you calculated in the previous part, determine which genotype would "win" (that is, survive and reproduce more than the other) if the two genotypes had to compete for resources in the kitchens described below. (Assume that the traps are hydramethylnon + corn syrup traps.) The absolute fitness of glu+/glu+ (survivorship x fecundity), absolute fitness of glu-/glu- (survivorship x fecundity), and relative fitness of glu-/glu- to glu+/glu+ A) Food containing glucose: 136, 65, 0.5 B) Food lacking glucose: 118, 116, 1.0 C) Hydramethylnon + corn syrup traps: 14,92, 6.6 Who is the winner of the kitchen: A) With food items out, plus traps B) With food items out, no traps C) Clean, plus traps D) Clean, no traps

B) If the Tamiflu-resistance gene involves a cost, it will experience directional selection leading to reduction in its frequency.

Swine are vulnerable to infection by bird flu virus and human flu virus, which can both be present in an individual pig at the same time. When this occurs, it is possible for genes from bird flu virus and human flu virus to be combined. If the human flu virus contributes a gene for Tamiflu resistance (Tamiflu is an antiviral drug) to the new virus, and if the new virus is introduced to an environment lacking Tamiflu, then what is most likely to occur? A) If the Tamiflu-resistance gene confers no benefit in the current environment, and has no cost, the virus will increase in frequency. B) If the Tamiflu-resistance gene involves a cost, it will experience directional selection leading to reduction in its frequency. C) The new virus will maintain its Tamiflu-resistance gene, in case of future exposure to Tamiflu. D) The Tamiflu-resistance gene will undergo mutations that convert it into a gene that has a useful function in this environment.

Which term describes the fusion of two gametes to form a diploid zygote?

Syngamy

Homoplasy Example

The eye, which has originated independently in many different species.

Which of the following observations led to Darwin's major inferences? - Members of a population vary in their heritable traits. - Body parts that are not used deteriorate over time. - Organisms only go extinct when catastrophes occur. - Although organisms can produce huge numbers of offspring, many of these offspring do not survive. - The first and fourth answers are correct.

The first and fourth answers are correct. (Both are important observations that led to Darwin's major inferences.)

Orthologous Genes

The genes in different species that evolved from a common ancestral gene by speciation. Normally, they retain the same function in the course of evolution. Identification of these genes is critical for reliable prediction of gene function in newly sequenced genomes.

Which of the following statements about the humoral immune response is true? A. The humoral immune response defends against bacteria and viruses by activating T cells. B. The humoral immune response is the result of macrophages producing antibodies. C. The humoral immune response plays a major role in protecting the body from cancerous cells. D. The humoral immune response defends primarily against bacteria and viruses present in body fluids.

The humoral immune response defends primarily against bacteria and viruses present in body fluids.

This phylogenetic tree was constructed by comparing sequences for a homologous gene involved in development. Select the correct statement.

The nucleotide sequence of this gene in a mouse is more similar to the sequence in a chicken, and both are less similar to the nucleotide sequence of this gene in a frog.

Which of the following statements about the evolution of Anolis lizards in the Caribbean islands is true?

The phylogeny of ecomorphs on a given island reveals that adaptive radiation has taken place.

A researcher who detects a higher-than-normal amount of interferon in a laboratory rat would correctly conclude that

The rat has, or recently had, a viral infection.

Varieties of Staphylococcus aureus that are resistant to the drug methicillin _____. - developed in response to the use of methicillin - already existed in the population before methicillin was developed - always have an advantage in every environment - were strongly selected for as methicillin became widely used to treat bacterial infections - The second and fourth answers are correct.

The second and fourth answers are correct. (Resistant varieties existed in the population but did not confer any advantage until the environment changed with the introduction of the drug methicillin.)

Which of the following distinguishes the secondary immune response from the primary immune response?

The secondary response is faster and stronger.

Members of two different species possess a similar-looking structure that they use in a similar fashion to perform the same function. Which information would best help distinguish between an explanation based on homology versus one based on convergent evolution? - The two species share many proteins in common, and the nucleotide sequences that code for these proteins are almost identical. - The two species live at great distance from each other. - The sizes of the structures in adult members of both species are similar in size. - Both species are well adapted to their particular environments.

The two species share many proteins in common, and the nucleotide sequences that code for these proteins are almost identical.

What advantage do organisms that reproduce sexually have over organisms that reproduce asexually?

Their offspring may be more adaptable to changes in the environment.

If the bacterium Staphylococcus aureus experiences a cost for maintaining one or more antibiotic-resistance genes, then what should happen in environments from which antibiotics are missing? - These genes should continue to be maintained in case the antibiotics ever appear. - The bacteria should start making and secreting their own antibiotics. - The bacteria should try to make the cost worthwhile by locating, and migrating to, microenvironments where traces of antibiotics are present. - These bacteria should be outcompeted and replaced by bacteria that have lost these genes.

These bacteria should be outcompeted and replaced by bacteria that have lost these genes.

Which of the following best describes chimpanzees?

They are omnivores.

Which of the following statements best describes theories? - They are nearly the same things as hypotheses. - They are supported by, and make sense of, many observations. - They are predictions of future events. - They cannot be tested because the described events occurred only once.

They are supported by, and make sense of, many observations.

Which is a true statement about memory cells? A. They engulf antigens bound by antibodies. B. They produce antibodies. C. They have a longer lifespan than plasma cells. D. The first time an antigen is encountered, memory cells become plasma cells.

They have a longer lifespan than plasma cells.

What does the x-axis of a Phylogenetic Tree represent?

Time

A) Roaches ate about the same amount from the dish with no hydramethylnon as they did from the control dish. B) Roaches ate about the same amount from the dish with no oleic acid as they did from the control dish. F) Roaches are refusing corn syrup.

To find out which ingredient the cockroaches are refusing, you can carry out a controlled experiment. Hydramethylnon is dissolved in oleic acid before being mixed with corn syrup to prepare the poisoned bait, so you should test all three ingredients. Suppose you conducted a feeding trial to test each ingredient. In the trial, a set of four agar dishes, three containing all except one ingredient and one with all three ingredients (the control), were weighed and placed 3 cm apart on the kitchen floor in an infested apartment. After two days, the dishes were weighed again to measure food consumption. You then repeated the trial 4 times and averaged the results. Based on the results of the feeding experiment, what conclusions can you draw? Select all that apply. A) Roaches ate about the same amount from the dish with no hydramethylnon as they did from the control dish. B) Roaches ate about the same amount from the dish with no oleic acid as they did from the control dish. C) Roaches ate about the same amount from the dish with no corn syrup as they did from the control dish. D) Roaches are refusing hydramethylnon. E) Roaches are refusing oleic acid. F) Roaches are refusing corn syrup.

True or false? Convergent evolution is said to have occurred if the mouse species on two islands with similar habitats are found to have similar characteristics even though they originated from different species that did not have these characteristics.

True

Fulse, In most fungi, fertilization is a two-step process consisting of the fusion of cells and then the fusion of nuclei in the fused cells.

True or false? In most fungi, fertilization is complete after the cells fuse together.

Which Anolis lizard ecomorph has long legs?

Trunk/ground

Ichthyosaurs were extinct aquatic reptiles distantly related to living lizards. Fossils show us that they had dorsal fins and tails, as do fish, even though their closest relatives were terrestrial reptiles that had neither dorsal fins nor aquatic tails. The dorsal fins and tails of ichthyosaurs and fish are - examples of convergent evolution. - homologous. - adaptations to a common environment. - Three of the responses above are correct. - Two of the responses above are correct.

Two of the responses above are correct.

Which of the following must exist in a population before natural selection can act upon that population? - genetic variation among individuals - sexual reproduction - variation among individuals in reproductive success - Three of the responses are correct. - Two of the responses are correct.

Two of the responses are correct.

Structures as different as human arms, bat wings, and dolphin flippers contain many of the same bones, these bones having developed from very similar embryonic tissues. How do biologists interpret these similarities? - by identifying the bones as being homologous structures - by the principle of convergent evolution - by proposing that humans, bats, and dolphins share a common ancestor - Three of the statements above are correct. - Two of the statements above are correct.

Two of the statements above are correct.

Over evolutionary time, many cave-dwelling organisms have lost their eyes. Tapeworms have lost their digestive systems. Whales have lost their hind limbs. How can natural selection account for these losses? - Natural selection cannot account for losses, only for innovations. - Under particular circumstances that persisted for long periods, each of these structures presented greater costs than benefits. - The ancestors of these organisms experienced harmful mutations that forced them to find new habitats that these species had not previously used. - Natural selection accounts for these losses by the principle of use and disuse.

Under particular circumstances that persisted for long periods, each of these structures presented greater costs than benefits.

A) Frequency-dependent selection

When imbalances occur in the sex ratio of sexual species that have two sexes (that is, other than a 50:50 ratio), the members of the minority sex often receive a greater proportion of care and resources from parents than do the offspring of the majority sex. This is most clearly an example of _____. A) Frequency-dependent selection B) Sexual selection C) Disruptive selection D) Stabilizing selection E) Balancing selection

B) No genetic drift can affect allele frequencies for the gene. Any condition that changes allele frequencies in the population represents a violation of the Hardy-Weinberg principle and means that the population will not be in Hardy-Weinberg equilibrium.

Which assumption must be correct for a population to be in Hardy-Weinberg equilibrium for a specific gene? A) The number of immigrants must equal the number of organisms emigrating. B) No genetic drift can affect allele frequencies for the gene. C) Natural selection must favor one phenotype. D)Mating must be nonrandom with respect to the gene.

E) Decreased genetic difference between the two populations

Which of the following is the most predictable outcome of increased gene flow between two populations? A) Lower average fitness in both populations B) Higher average fitness in both populations C) Increased genetic difference between the two populations D) Increased genetic drift E) Decreased genetic difference between the two populations

C) The direction of evolutionary change due to genetic drift is random. Genetic drift is not driven by a directional effect but occurs as a magnification of chance effects due to small population size.

Which statement about genetic drift is correct? A) Genetic drift results from migration of new individuals into a population. B) Genetic drift becomes increasingly important with increasing population size. C) The direction of evolutionary change due to genetic drift is random. D) Genetic drift increases adaptation of individuals to their environment.

B) The cells that acquire these deleterious mutations are selected against by natural selection and these mutations are lost from the population over time.

Why don't the spontaneous deleterious mutations that occur in an individual E.coli cause downward drops in fitness in this population? See Section 23.6 (Page 475) . A) Deleterious mutations don't occur; the only mutations that occur are beneficial. B) The cells that acquire these deleterious mutations are selected against by natural selection and these mutations are lost from the population over time. C) Only deleterious mutations are lost by genetic drift in this population. D) Only beneficial mutations are fixed by genetic drift in this population.

ascomycete

You are given an organism to identify. It has a fruiting body that contains many structures with eight haploid spores lined up in a row. What kind of a fungus is this? -zygomycete -ascomycete -basidiomycete -chytrid -deuteromycete

B) Glucose aversion is an incompletely dominant trait. Glucose aversion is an incompletely dominant trait. You can tell this from the graph because the heterozygous F1 offspring consumed an intermediate amount of glucose compared to the parental cockroaches. The glu-/glu- parental cockroaches consumed less of the solution as the glucose concentration increased. The glu+/glu+ parental cockroaches consumed more of the solution as the glucose concentration increased. And the glu+/glu- F1 cockroaches consumed less of the solution as the glucose concentration increased, but still more than the glu-/glu- cockroaches. Neurophysiological studies of the glu-/glu- cockroaches' brains revealed that their glucose-sensing cells and bitter-sensing cells were inversely connected, leading them to perceive glucose as a bitter compound. In fact, these roaches spit glucose out when it is fed to them directly. Heterozygous glu+/glu- F1 cockroaches had a mix of normal and inversed sensing cells so that they tasted glucose as both sweet and bitter instead of one or the other.

You divide the roaches into four groups. Each group contains both types of parental roaches (glu-/glu- and glu+/glu+ ) and F1 roaches (glu-/glu+ ): Group 1 is fed a solution containing no glucose. Group 2 is fed a 100 mM glucose solution. Group 3 is fed a 300 mM glucose solution. Group 4 is fed a 500 mM glucose solution. Glucose itself is hard to measure in a cockroach, so a tracking dye needs to be added to the test solutions. After feeding, individual roaches are harvested, the dye is extracted from their bodies, and the amount of dye (representing the volume of glucose test solution ingested) is measured with a spectrophotometer. The results are shown in the graph below. Which hypothesis do these results support? A) Glucose aversion is a learned behavior. B) Glucose aversion is an incompletely dominant trait. C) Glucose aversion is a dominant trait. D) Glucose aversion is a recessive trait.

While playing soccer in your backyard, you disrupt a small fire ant mound. The fire ants emerge and bite your feet. Your feet begin to show swollen, raised areas around the bites. What is happening?

Your innate internal defenses have been activated.

Which of the following is a chimpanzee most likely to use a tool to help catch?

a bush baby

You are a primatologist studying chimpanzee behavior. According to this recent study, which of the following are you most likely to see using a tool?

a female chimpanzee

Which of the following is true of generalized bacteriophage transduction? a.) The bacteriophage packages fragments of bacterial DNA into new phage particles. b.) The bacteriophage chromosome has a region homologous to the bacterial chromosome. c.) The bacteriophage must enter the lysogenic cycle.

a.) The bacteriophage packages fragments of bacterial DNA into new phage particles During transduction, phages package fragments of bacterial DNA into new phage heads. This bacterial DNA can be transferred to another bacteria cell during the next phage infection.

Anaphylactic shock is an example of an

allergic response.

Radiometric dating _____.

allows us to indirectly date fossils up to billions of years old based on minerals in surrounding volcanic strata

Passive immunity can be obtained from __________.

an injection of antibodies that recognize invading microbes

The region of an antigen to which an antibody binds is termed the _____.

antigenic determinant

The oldest fossils usually _____.

are found in the deepest strata

What type of immune response is always disadvantageous to a person?

autoimmune

Of the following anatomical structures, which is homologous to the bones in the wing of a bird? - bony rays in the tail fin of a flying fish - cartilage in the dorsal fin of a shark - bones in the hind limb of a kangaroo - bones in the flipper of a whale - chitinous struts in the wing of a butterfly

bones in the flipper of a whale

Which protists are in the same eukaryotic supergroup as land plants?

both red algae and green algae

A phylogenetic tree constructed using sequence differences in mitochondrial DNA would be most valid for discerning the evolutionary relatedness of ______.

chimpanzees and humans

To apply parsimony to constructing a phylogenetic tree, _____.

choose the tree that represents the fewest evolutionary changes, either in DNA sequences or morphology

The role that humans play in artificial selection is to - choose which organisms breed, and which do not. - perform artificial insemination. - create the genetic variants, which nature then selects. - determine who lives and who dies. - train organisms to breed more successfully.

choose which organisms breed, and which do not.

A paramecium is a(n) _____.

ciliate

All of the organisms classified as _____ move and feed using cilia.

ciliates

The proliferation of the B lymphocyte to which a specific antigen binds is referred to as _____. (Be specific.)

clonal selection

The prokaryotic cells that built stromatolites are classified as _____.

cyanobacteria

The prokaryotic cells that were the first to add significant quantities of oxygen to Earth's atmosphere are classified as _____.

cyanobacteria which are aerobic photosynthesizers

Which of these groups is characterized by glasslike walls containing silica?

diatoms

When a B cell first interacts with its particular antigen, the B cell

differentiates and develops into a clone of antibody-producing effector cells

The cells of _____ and _____ have modified mitochondria.

diplomonads ...parabasalids

A challenge to traditional (pre-1860) ideas about species came from embryology, when it was discovered that _____. - all animals develop similar embryonic gills - embryos of dissimilar organisms, such as sharks and humans, resemble each other - the more advanced the animal, the more slowly it develops - the embryological development of many plants and animals is almost identical - mutations have a far more dramatic effect on embryos than on adult organisms

embryos of dissimilar organisms, such as sharks and humans, resemble each other (Early in development, the similarities among all vertebrate embryos are more apparent than the differences.)

Animals that possess homologous structures probably _____.

evolved from the same ancestor

True or false? Organisms that exhibit alternation of generations reproduce sexually in the diploid stage.

false

The wing of a bat is homologous to the _____ of a whale. - flipper - rib cage - tail - blowhole - baleen

flipper (The bones of a bat wing and a whale flipper are homologous.)

Which of the following compounds is produced and secreted by mast cells during an allergic reaction? A. perforin B. allergens C. interferon D. histamine

histamine

Species that are not closely related and that do not share many anatomical similarities can still be placed together on the same phylogenetic tree by comparing their _____.

homologous genes that are highly conserved

The common ancestors of birds and mammals were very early (stem) reptiles, which almost certainly possessed three-chambered hearts (two atria, one ventricle). Birds and mammals, however, are alike in having four-chambered hearts (two atria, two ventricles). The four-chambered hearts of birds and mammals are best described as ______.

homoplasies

If, someday, an archaean cell is discovered whose rRNA sequence is more similar to that of humans than the sequence of mouse rRNA is to that of humans, the best explanation for this apparent discrepancy would be _____.

homoplasy

Which process occurred frequently in the early history of the three domains on Earth, and makes determining phylogenetic relationships of that time difficult?

horizontal gene transfer

DNA sequences in many human genes are very similar to the sequences of corresponding genes in chimpanzees. The most likely explanation for this result is that - humans evolved from chimpanzees. - humans and chimpanzees share a relatively recent common ancestor. - humans and chimpanzees are not closely related. - chimpanzees evolved from humans. - convergent evolution led to the DNA similarities.

humans and chimpanzees share a relatively recent common ancestor.

The rise of methicillin-resistant Staphylococcus aureus (MRSA) can be considered to be an example of artificial selection because - humans synthesize methicillin and create environments in which bacteria frequently come into contact with methicillin. - humans are becoming resistant to bacteria by taking methicillin. - S. aureus is cultivated by humans to replenish the soil with nutrients. - humans purposefully raise MRSA in large fermenters in an attempt to make the bacteria ever-more resistant.

humans synthesize methicillin and create environments in which bacteria frequently come into contact with methicillin.

The thymus is most active during childhood. A child with a malfunctioning thymus will have trouble with __________.

humoral and cell-mediated immunity

Natural selection is based on all of the following except - populations tend to produce more individuals than the environment can support. - genetic variation exists within populations. - individuals who survive longer tend to leave more offspring than those who die young. - individuals adapt to their environments and, thereby, evolve. - the best-adapted individuals tend to leave the most offspring.

individuals adapt to their environments and, thereby, evolve.

Regarding these sequence homology data, the principle of maximum parsimony would be applicable in _____.

inferring evolutionary relatedness from the number of sequence differences

It has been observed that organisms on islands are different from, but closely related to, similar forms found on the nearest continent. This is taken as evidence that - common environments are inhabited by the same organisms. - island forms and mainland forms descended from common ancestors. - the islands were originally part of the continent. - the island forms and mainland forms are converging. - island forms and mainland forms have identical gene pools.

island forms and mainland forms descended from common ancestors.

As an allergy sufferer, _____ are some of my least favorite cells.

mast cells

Which cell type is responsible for the symptoms of allergies? A. B cells B. helper T cells C. cytotoxic T cells D. mast cells

mast cells

Monoclonal antibodies are a successful driving force of therapy in the treatment of asthma. The use of antibodies to treat asthma is an application of

medical research in a laboratory setting.

Which of the following types of cells initiates a secondary immune response? A. immature white blood cells B. natural killer cells C. memory cells D. effector cells

memory cells

A clade is _____.

monophyletic

Which of the following is an autoimmune disease? A. Hodgkin's disease B. AIDS C. multiple sclerosis D. SCID

multiple sclerosis

Cladograms (a type of phylogenetic tree) constructed from evidence from molecular systematics are based on similarities in _____.

mutations to homologous genes

A researcher wants to determine the genetic relatedness of several breeds of dog (Canis lupus familiaris). The researcher should compare homologous sequences of this type of biochemical________-which can be described as ________.

nucleic acids, poorly conserved

Molecular clocks are based on the idea that _____.

on average neutral mutations arise at a constant rate

From his observations of organisms in the Galapagos islands, Darwin reasoned that _____. - all island species should be similar to each other - the organisms in the Galapagos had been specially created to thrive in that environment - organisms had adapted to new environments, giving rise to new species - the shape of a bird's beak does not affect its ability to survive and reproduce - none of the above

organisms had adapted to new environments, giving rise to new species (Darwin reasoned that natural selection had increased the match between the organisms and their environment.)

Concerning growth in genome size over evolutionary time, which of these is least associated with the others?

orthologous genes

Humans, chimpanzees, gorillas, and orangutans are members of a clade called the great apes, which shared a common ancestor about 18 million years ago. Gibbons and siamangs comprise a clade called the lesser apes. Tree-branch lengths indicate elapsed time. Assuming chimps and gorillas are humans' closest relatives, removing humans from the great ape clade and placing them in a different clade has the effect of making the phylogenetic tree of the great apes _____.

paraphyletic

The basic function of activated T cells is to battle

pathogens that have already entered body cells.

Some molecular data place the giant panda in the bear family (Ursidae) but place the lesser panda in the raccoon family (Procyonidae). Consequently, the morphological similarities of these two species are probably due to _____.

possession of analogous structures

The earliest organisms were most likely _____.

prokaryotic

Which of these algal groups possess a photosynthetic pigment that allows them to live in deep water?

red algae

The two main functions of the lymphatic system are

returning tissue fluid to the circulatory system and fighting infections.

In a hypothetical environment, fishes called pike-cichlids are visual predators of algae-eating fish (in other words, they locate their prey by sight). If a population of algae-eaters experiences predation pressure from pike-cichlids, which of the following is least likely to be observed in the algae-eater population over the course of many generations? - selection for algae-eaters that are faster swimmers - selection for nocturnal algae-eaters (active only at night) - selection for larger female algae-eaters, bearing broods composed of more, and larger, young - selection for algae-eaters that become sexually mature at smaller overall body sizes - selection for drab coloration of the algae-eaters

selection for larger female algae-eaters, bearing broods composed of more, and larger, young

Fossil evidence indicates that some dinosaurs had feathers. If birds are indeed descended from dinosaurs, feathers are what kind of character?

shared ancestral character

When using a cladistic approach to systematics, which of the following is considered most important for classification?

shared derived characters

Spiral-shaped bacteria are likely to be placed with _____.

spirochetes

To which part of an antigen does an antibody bind?

the antigenic determinant

Helper T cells are part of _____.

the cell-mediated immune response

A physician diagnoses a patient with a bacterial infection and determines that the patient is not immune to the bacteria. He delivers a shot of blood plasma that contains antibodies to his patient. The physician is transferring

the humoral immune response.

A primary immune response is

the immune response elicited by the first exposure of lymphocytes to a particular antigen.

The idea behind vaccination is to induce _____ without the vaccinated individual having to get sick.

the primary immune response

A group of small fish live in a lake with a uniformly light-brown sandy bottom. Most of the fish are light brown, but about 10% are mottled. This fish species is often prey for large birds that live on the shore. A construction company dumps a load of gravel in the bottom of the lake, giving it a mottled appearance. Which of these statements presents the most accurate prediction of what will happen to this fish population? - The proportion of mottled fish will increase over time. - As the mottled fish are eaten, more will be produced to fill the gap. - The ratios will not change. - In two generations, all the fish will be mottled. - There is no way to predict the result.

the proportion of mottled fish will increase over time. (The mottled fish will tend to escape predation because they are camouflaged against the mottled lake bottom. The mottled fish will most likely produce more offspring.)

Hox genes are thought to play an important role in the development of different morphologies because _____.

they provide positional information in the embryo

If two modern organisms are distantly related in an evolutionary sense, then one should expect that - they should be members of the same genus. - their chromosomes should be very similar. - they live in very different habitats. - they shared a common ancestor relatively recently. - they should share fewer homologous structures than two more closely related organisms.

they should share fewer homologous structures than two more closely related organisms.

Miller and Urey's experiments that attempted to recreate conditions on early Earth were significant because _____.

they showed that organic molecules such as amino acids could be produced from inorganic molecules

The following question refers to the figure, which shows an outcrop of sedimentary rock whose strata are labeled A-D. If x indicates the fossils of two closely related species, neither of which is extinct, then their remains may be found in how many of these strata? - two strata - four strata - one stratum - three strata

two strata

The atmosphere of early Earth probably contained no O2 until the emergence of organisms that _____.

used water as an electron source for photosynthesis

Which of the following disease-causing organisms is most similar to that which causes Zika? A. bacterium that causes Lyme disease B. protozoan that causes malaria C. virus that causes HIV D. nematode that causes onchocerciasis

virus that causes HIV

You perform a bacteriophage transduction experiment. The donor bacteria strain has the genotype a+ b+ c+ d+. The recipient bacteria strain has the genotype a- b- c- d-. Genotype Number of cotransduced cells a+ and b+ 0 a+ and c+ 10 a+ and d+ 0 b+ and c+ 2 b+ and d+ 10 c+ and d+ 0 When you analyze the recipients, you obtain the results shown in this data table.

---A--c---------b-d The relative location of genes on the bacterial chromosome can be determined by the frequency at which they cotransduce. Genes that are closely linked on the bacterial chromosome are more likely to be cotransduced -- 10 cells contained the cotransduced a and c genes, which means these two genes are close together on the bacterial chromosome. Genes that are not linked will only rarely (or never) cotransduce -- no cells contained contransduced a and b genes or a and d genes, which means that a must be far away from both b and d on the bacterial chromosome. Then, using the cotransduction data for the c and b genes (2 cells) and the c and d genes (0 cells), you can determine that gene b is closer to gene c than is gene d.

Azotobacter is a genus of bacteria that live in soil and have the following characteristics: •They are bacilli. •They are gram-negative. •They are obligate aerobes. •They can fix nitrogen. (Unlike some other nitrogen-fixing bacteria, which associate with the roots of plants, Azotobacter species are free-living.) Select the four statements that are true for bacteria in the genus Azotobacter: -They require amino acids or other organic molecules as a source of nitrogen. -They appear purple after Gram staining. -They can carry out anaerobic respiration in an environment that lacks O2. -They are shaped like rods. -They have a relatively thin layer of peptidoglycan in their cell wall. -They have the appearance of coils or corkscrews. -They can convert atmospheric nitrogen to ammonia. -They use O2 for cellular respiration. -They are poisoned by O2.

-They are shaped like rods -They have a relatively thin layer of peptiodglycan in their cell wall -They can convert atmospheric nitrogen to ammonia -They use O₂ for cellular respiration

Phylogenetic Tree

A way of depicting the evolutionary history of a group of organisms. They are all works in progress. Represents a hypothesis of the history of the species.

The members of _____ are characterized by cells with small membrane-bounded cavities under their cell membranes.

Alveolata

Ascospores have undergone genetic recombination during their production, whereas conidia have not.

Among sac fungi, which of these correctly distinguishes ascospores from conidia? Ascospores are larger, whereas conidia are smaller. Ascospores will germinate into haploid hyphae, whereas conidia will germinate into diploid hyphae. Ascospores are diploid, whereas conidia are haploid. Ascospores have undergone genetic recombination during their production, whereas conidia have not. Ascospores are produced only by meiosis, whereas conidia are produced only by mitosis. SubmitMy AnswersGive Up

animals

Among the organisms listed here, which are thought to be the closest relatives of fungi? -vascular plants -brown algae -animals -mosses -slime molds

Mycorrhizae are mutualistic associations with the roots of plants, which enhance the absorption of nutrients.

An important example of interaction between fungi and certain other organisms is mycorrhizae, in which the fungal partners _____. -cause the decay of cellulose and lignin -help plants take up nutrients and water -sicken herbivores that attempt to feed on plants -provide carbohydrates to the plant partner -control soil nematodes

plasmogamy

At which stage of a basidiomycete's life cycle would reproduction be halted if an enzyme that prevented the fusion of hyphae was introduced? -plasmogamy -germination -karyogamy -fertilization

what are ways the bacteria can acquire new genes?

Bacteria can acquire new genes from the environment through transformation, by direct contact with another bacteria cell through conjugation, or by being infected with a bacteriophage through transduction.

meiosis, Basidia produce spores by meiosis.

Basidia produce spores by a process known as ____. decomposition mitosis meiosis hyphae binary fission

Which of the following statements supports the hypothesis of an endosymbiotic origin of mitochondria?

Each mitochondrion has its own DNA molecule

According to this phylogenetic tree, which of these pairs of prokaryotic subgroups share the most recent common ancestor?

Euryarchaeota ... Crenarchaeota

by flagella

For several decades now, amphibian species worldwide have been in decline. A significant proportion of the decline seems to be due to the spread of the chytrid fungus, Batrachochytrium dendrobatidis (Bd). Chytrid sporangia reside within the epidermal cells of infected animals, animals that consequently show areas of sloughed skin. They can also be lethargic, which is expressed through failure to hide and failure to flee. The infection cycle typically takes four to five days, at the end of which zoospores are released from sporangia into the environment. In some amphibian species, mortality rates approach 100%; other species seem able to survive the infection. Apart from direct amphibian-to-amphibian contact, what is the most likely means by which the zoospores spread from one free-living amphibian to another? For several decades now, amphibian species worldwide have been in decline. A significant proportion of the decline seems to be due to the spread of the chytrid fungus, Batrachochytrium dendrobatidis (Bd). Chytrid sporangia reside within the epidermal cells of infected animals, animals that consequently show areas of sloughed skin. They can also be lethargic, which is expressed through failure to hide and failure to flee. The infection cycle typically takes four to five days, at the end of which zoospores are released from sporangia into the environment. In some amphibian species, mortality rates approach 100%; other species seem able to survive the infection. Apart from direct amphibian-to-amphibian contact, what is the most likely means by which the zoospores spread from one free-living amphibian to another? -by wind-blown spores -by hyphae -by cilia -by flagella -by pseudopods

absorption, Fungi are heterotrophs that acquire their nutrients by absorbing small molecules from the surrounding medium.

Fungi obtain nutrients through _____. -endocytosis -ingestion -absorption -chemosynthesis -photosynthesis

The production of saclike structures during sexual reproduction is characteristic of the phylum Ascomycota.

Fungi of the phylum Ascomycota are recognized on the basis of their production of _____ during sexual reproduction. -lichens -yeasts -flagellated zoospores -saclike structures -a dikaryotic structure

surroundings, Fungi then absorb the digested nutrients.

Fungi release digestive enzymes into their _____. surroundings gastrovascular cavity stomach hyphae mycelia

Which term describes the multicellular haploid form of a protist that shows alternation of generations?

Gametophyte

How does the haploid form of Ulva "switch" to its diploid form?

Gametophytes produce cells that undergo mitosis to produce gametes that fuse to form a zygote.

Which of the following statements about Ulva's haploid stage is true?

Haploid cells are produced by meiosis of diploid cells.

Which structure mediates the attachment of spores to a surface on which to grow?

Holdfast

conidiophores

In what structures do both Penicillium and Aspergillus produce asexual spores? -rhizoids -zygosporangia -conidiophores -asci -gametangia

Which form of Plasmodium is the immediate cause of anemia in humans?

Merozoites

Which of the features below are found in all protist lineages?

Mitochondria

decomposers, Fungi obtain nutrients from nonliving organic matter.

Most fungi are _____. -photoautotrophs -decomposers -herbivores -carnivores -chemoautotrophs

Which species interaction applies to bees that harvest nectar and pollen from flowers?

Mutualism.

identify key features of the 5 major groups of bacteria

Proteobacteria: •photosyntheic •nitrogen fixing •disease-causing Chlamydias: •parasitic •disease causing Spirochetes •flagellum •corck-screw motion •disease-causing •digests wood Gram-positive bacteria: •disease causing •food production •lost cell wall •smallest Cyanobacteria: •photosynthetic •aquatic producer/nitrogen fixers

2 and 3, They do not form heterokaryons and their spores are probably produced by mitosis.

Sexual reproduction has never been observed among the fungi that produce the blue-green marbling of blue cheeses. What is true of these fungi and others that do not have a sexual stage? 1) They are currently classified among the ascomycetes. 2) They do not form heterokaryons. 3) Their spores are probably produced by mitosis. 4) They form dikaryotic mycelium. 5) The spores undergo crossing over during meiosis.

mutualistic

Some fungal species can kill herbivores while feeding off of sugars from its plant host. What type of relationship does this fungus have with its host? -mutualistic -parasitic -commensal -predatory

Which group is characterized by cells with fine hairlike projections on their flagella?

Stramenopila

an extensive surface area well suited for invasive growth and absorptive nutrition.

The adaptive advantage associated with the filamentous nature of fungal mycelia is primarily related to -avoiding sexual reproduction until the environment changes. -an extensive surface area well suited for invasive growth and absorptive nutrition. -the ability to form haustoria and parasitize other organisms. -the increased probability of contact between different mating types. -the potential to inhabit almost all terrestrial habitats.

hyphae ... mycelium, Hyphae form a network called a mycelium.

The body of most fungi consists of threadlike _____, which form a network called a _____.

Systematics

The branch of biology that deals with classification of organisms; taxonomy. Meant to reflect evolutionary history.

The following figure depicts the outline of a large fairy ring that has appeared overnight in an open meadow, as viewed from above. The fairy ring represents the furthest advance of this mycelium through the soil. Locations A-D are all 0.5 meters below the soil surface. What is the most probable location of the oldest portion of this mycelium?

a green alga

The photosynthetic symbiont of a lichen is often a small vascular plant. -an ascomycete. -a moss. -a green alga. -a brown alga.

True, A mushroom consists mainly of hyphae that are heterokaryotic, which means they have two distinct haploid nuclei per cell; these nuclei may fuse in specialized cells called basidia and become diploid in preparation for meiosis and spore production.

True or false? Most of the cells in a mushroom contain haploid nuclei.

The sporangia of the bread mold Rhizopus are asexual structures that produce haploid spores.

What are the sporangia of the bread mold Rhizopus? -asexual structures that produce haploid spores -sexual structures that produce diploid spores -sexual structures that produce haploid spores -asexual structures that produce diploid spores

karyogamy and meiosis, During karyogamy, the haploid nuclei fuse, and meiosis produces genetic variation in several ways.

What sexual processes in fungi generate genetic variation? -karyogamy and meiosis -budding and meiosis -haustoria and karyogamy -diploidy and the heterokaryotic condition -plasmogamy and meiosis

fungicide might also kill mycorrhizae.

When pathogenic fungi are found growing on the roots of grape vines, grape farmers sometimes respond by covering the ground around their vines with plastic sheeting and pumping a gaseous fungicide into the soil. The most important concern of grape farmers who engage in this practice should be that the....

Systematics Example

When you learn that a chimpanzee is a primate, and all primates are mammals. The fact that Humans and Chimpanzees are both primates, but a Cat is not, reflects the fact that Humans and Chimpanzees share a more recent evolutionary history than Humans and Cats or Chimpanzees and Cats.

Basidia are specialized cells in the gills of a mushroom in which haploid nuclei fuse in preparation for meiosis.

Where does meiosis occur in a mushroom? -Spores -Basidia -Mycelium -Hyphae

flagellated spores

Which feature seen in chytrids supports the hypothesis that they diverged earliest in fungal evolution? -parasitic lifestyle -the absence of chitin within the cell wall -coenocytic hyphae -flagellated spores

Photosynthetic cells are surrounded by fungal hyphae.

Which of the following best describes the physical relationship of the partners involved in lichens? -Fungal cells are enclosed within algal cells. -Lichen cells are enclosed within fungal cells. -The fungi grow on rocks and trees and are covered by algae. -Photosynthetic cells are surrounded by fungal hyphae.

Photosynthetic cells are surrounded by fungal hyphae.

Which of the following best describes the physical relationship of the partners involved in lichens? -Fungal cells are enclosed within algal cells. -The fungi grow on rocks and trees and are covered by algae. -Lichen cells are enclosed within fungal cells. -Photosynthetic cells are surrounded by fungal hyphae. -Algal cells and fungal cells mix together without any apparent structure.

conidiophores

Which of the following cells or structures are associated with asexual reproduction in fungi? -Zygosporangia -basidiospores -ascocarps -conidiophores -ascospores

The presence of flagella is a characteristics is unique to chytrids compared to other groups of fungi?

Which of the following characteristics is unique to chytrids compared to other groups of fungi? -presence of flagella -autotrophic mode of nutrition -cell walls of cellulose -heterotrophic mode of nutrition -nucleotide sequences of several genes

The spore undergoes mitosis to produce hyphae, which then form a filamentous network called a mycelium.

Which of the following events occurs first in the development of a spore into a mature mushroom? -A heterokaryotic mycelium forms. -The mycelium forms. -Haploid nuclei fuse to form a diploid nucleus. -Hyphae are produced by mitosis.

The mycelium is a mass of filaments with a high surface-area-to-volume ratio, which allows for efficient nutrient absorption.

Which structure allows the growing mushroom to nourish itself? -Basidia -Mycelium -Gills -Spore

A mycelium is a network of filaments that forms the body of a fungus.

Which structure is not directly involved in the reproduction of at least one major group of fungi? -Mycelium -Basidium -Motile spores -Asci

Plasmogamy is the fusion of cytoplasm from different individuals.

Which term describes the fusion of cytoplasm from two individuals? -Spore -Karyogamy -Heterokaryotic -Plasmogamy

Biologists suspect that endosymbiosis gave rise to mitochon-dria before plastids partly because

all eukaryotes have mitochondria (or their remnants), whereas many eukaryotes do not have plastids

Plasmodium, the parasitic organism that causes malaria, is a _____.

apicomplexan

The largest seaweeds are _____.

brown algae

Which three groups contain large algae known as seaweeds?

brown algae, red algae, and green algae

Organisms that can cause nongonococcal urethritis are classified with _____.

chlamydias

Which algal group has chloroplasts much like those of green plants in structure and pigment makeup?

chlorophytes

distinguish between the three process of genetic transfer in bacteria

conjugation: -involves the transfer of DNA from an Hfr cell to an F⁻ cell -requires cell-to-cell contact transduction: -involves bacteriophage transferring pieces of bacterial DNA from one cell to another transformation: -involves DNA from the environment being taken up into a bacterial cell All three: -involves recombination

how does gene transfer help a bacterial species survive?

gene transfer allows the transfer of antibiotic resistance genes to spread in a species of bacteria

Streptococcus pyogenes is classified with _____.

gram-positive bacteria

distinguish between gram-positive bacteria & gram-negative bacteria.

gram-positive bacteria: •have a thick peptidoglycan layer •appear purple after Gram staining •alcohol rinse does not remove crystal violet Gram-negative bacteria: •have a thin peptidoglycan layer •appear pink after Gram staining •alcohol rinse easily removes crystal violet •have an outer membrane as part of their cell wall structure both: •have a plasma membrane

Label the diagram below to show the relationship between nutritional modes of bacteria.

http://www.chegg.com/homework-help/questions-and-answers/label-diagram-show-relationship-nutritional-modes-bacteria-drag-labels-appropriate-locatio-q10745827 From left to right: autotroph - heterotroph chemoautotroph - photoautotroph - photoheterotroph - chemoheterotroph phototrophs chemotrophs Some bacteria obtain energy from light (phototrophs), whereas other bacteria obtain energy from chemicals (chemotrophs). Autotrophs (literally "self-feeders") require only an inorganic substance, such as carbon dioxide, as their carbon source; heterotrophs (literally "other-feeders") require at least one organic nutrient as their carbon source.

What is the point of genetic recombination?

it aids in diversity

Which of these groups consist of parasitic flagellated cells, such as Trypanosoma, the organism that causes sleeping sickness?

kinetoplastids

In life cycles with an alternation of generations, multicellular haploid forms alternate with

multicellular diploid forms

Humans, chimpanzees, gorillas, and orangutans are members of a clade called the great apes, which shared a common ancestor about 18 million years ago. Gibbons and siamangs comprise a clade called the lesser apes. Tree-branch lengths indicate elapsed time. Together, the lesser apes and great apes shared a common ancestor most recently with other members of their _____.

order

Golden algae, brown algae, red algae, chlorophytes, and charophyceans are some examples of protists that are _____.

photosynthetic

Plastids that are surrounded by more than two membranes are evidence of

secondary endosymbiosis

The various taxonomic levels (namely, genera, classes, etc.) of the hierarchical classification system differ from each other on the basis of _____.

their inclusiveness

what is the point of horizontal gene transfer?

to help bacteria respond and adapt to their environment much more rapidly by acquiring large DNA sequences from another bacterium in a single transfer.

True or false? One example of a coevolutionary arms race is when faster deer evolve and favor wolves and cougars that have stronger eyesight and senses of smell.

true

what is horizontal gene transfer?

when individual members from different species exchange DNA

Antibiotic-resistant bacteria are becoming an increasing problem. Some bacteria that were once killed by common antibiotics have acquired the ability to survive in the presence of those antibiotics. What are ways that bacteria can acquire antibiotic resistance?

•Bacteria can acquire random mutations that allow them to grow in the presence of antibiotics. •Bacteria can gain an antibiotic-resistance gene by conjugating with another species of bacteria. •Bacteria can pick up an antibiotic-resistance gene from the environment through transformation. •Bacteria can acquire antibiotic-resistance genes by becoming infected with a virus that contains an antibiotic-resistance gene. Bacteria can acquire antibiotic resistance by a variety of methods, including random mutation and genetic transfer by transformation, transduction, or conjugation.

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