Chapter 1: Studying Life (HOMEWORK & QUIZ)

Which are the two main lineages of prokaryotes that diverged early in life's history? A) Bacteria and Archaea B) Eukarya and Microbial Eukaryotes C) Archaea and Eukarya D) Bacteria and Eukarya E) Microbial eukaryotes and Bacteria

A) Bacteria and Archaea

Colony collapse disorder that has been decimating bee colonies was first reported around 2006. Massive numbers of honey bees were suddenly dying for unexplained reasons. Researchers have since discovered that major factors causing these die-offs are infestations by parasitic mites and pesticides used on crops. Which is the best explanation for how this information can be useful to agriculture? A) Bees are major pollinators of crops, so it is important to know which pesticides to manage in order to avoid risk to bee survival. B) Bees are beautiful insects, so learning how to preserve them for future generations is important. C) Knowing what kills bees could help people avoid being stung by bees. D) Knowing how to protect bees is important so that students can learn about social insects. E) Knowing how to protect honey bees will help preserve an important food source for bears.

A) Bees are major pollinators of crops, so it is important to know which pesticides to manage in order to avoid risk to bee survival.

Which statement about model systems is true? A) The results of a study of a model organism, such as a fruit fly, might be extended to humans. B) Much of what we know about the genes that control animal development has come from work on Arabidopsis thaliana. C) Basic understanding of chemical reactions in eukaryotic cells can only come from research on eukaryotes. D) The biochemistry of photosynthesis was worked out from experiments on roundworms. E) Knowledge of how animals develop has come from work on Chlorella.

A) The results of a study of a model organism, such as a fruit fly, might be extended to humans.

Analyze the following question to determine whether it is a scientific question or a non-scientific question, and explain why: What causes cancer? A) This is a scientific question because scientists can gather data through experimentation that provide support for answers to this question. B) This is a non-scientific question because scientists have been working to try to answer it for decades and still cannot answer it completely. C) This question does not qualify as either a scientific or non-scientific question because it is too broad to classify. D) This is a scientific question because it deals with a medical topic and medicine is a branch of science. E) This is a non-scientific question because today's scientists do not have all of the tools they would need to answer it.

A) This is a scientific question because scientists can gather data through experimentation that provide support for answers to this question.

Genetic information A) can be passed on to offspring. B) is only found in animal and plant cells. C) is identical for all living cells. D)continues unchanging from one generation to the next. E) originates in the proteins in a cell.

A) can be passed on to offspring.

The initial accumulation of oxygen in the atmosphere was the result of photosynthesis from an organism most like modern A) cyanobacteria. B) eukaryotes. C) kelp. D) algae. E) mosses.

A) cyanobacteria.

Which of the following is required for natural selection to occur? A) Organisms in a population must have the same traits. B) A trait must be heritable so that it is capable of being passed onto future generations. C) A trait must decrease survival. D) A trait must decrease reproductive success. E) A trait must be capable of change within a single individual.

B) A trait must be heritable so that it is capable of being passed onto future generations.

Which statement provides evidence that an organ system provides a level of function not possible with individual organs operating independently? A) Bears grow thick fur on their bodies. B) Blood circulates to all tissues of a horse's body. C) Humans produce antibodies that bind to invading pathogens. D) Bones in mammals are composed of living cells. E) The dog stomach produces digestive enzymes.

B) Blood circulates to all tissues of a horse's body.

Which correctly lists the order of important first events in the history of life? A) First archaea, chemical evolution, first chloroplasts, first nucleus, first cyanobacteria B) Chemical evolution, first archaea, first cyanobacteria, first nucleus, first chloroplasts C) Chemical evolution, first cyanobacteria, first archaea, first chloroplasts, first nucleus D) First cyanobacteria, first nucleus, first archaea, first chloroplasts, chemical evolution E) First cyanobacteria, chemical evolution, first archaea, first nucleus, first chloroplasts

B) Chemical evolution, first archaea, first cyanobacteria, first nucleus, first chloroplasts

In 1928, British bacteriologist Alexander Fleming made an accidental discovery. He noticed that a fungus had contaminated one of the agar plates he had streaked with a bacterial species to be studied. The fungus prevented the bacteria from growing in the immediate area surrounding the fungus. Upon further investigation, Fleming found that the fungus produced a substance that was the agent responsible for killing the bacteria. He called this substance penicillin. Given this information, which statement best explains why Fleming's discovery is relevant to the general public today? A) Fleming's sloppiness in the lab serves as a reminder to all researchers that sterile technique is critical to preventing unwanted fungal growth on bacterial plates. B) Fleming's discovery enabled the development of chemical substances as antibiotics to treat deadly bacterial infections. C) Fleming's work revealed the ability of bacteria to mutate, which necessitates the constant search for new antibiotics. D) Fleming's attention to detail diverted his efforts to investigate bacteria and likely robbed humanity of important discoveries that he would have otherwise made. E) Fleming's research spawned new questions about the ecological interactions between fungi and bacteria.

B) Fleming's discovery enabled the development of chemical substances as antibiotics to treat deadly bacterial infections.

Prior to the industrial revolution in the mid-1800s, a species of moth had light-colored wings speckled with small black spots. This coloration camouflaged the moths resting on the birch trees growing in their native habitat, since birch bark has similar coloring. In the early 1900s, this changed as dark soot produced by industrial pollution coated birch trees such that the trees lost their speckled coloring. Years later, it was observed that the moths of this species had changed from being light and speckled to being solid black. Which is the most plausible reason for this change? A) Both birds and moths evolved to become better able to survive since evolution always causes change in the direction of improving any species. B) Speckled moths declined and darker variants rose in numbers, as birds could more easily prey on speckled moths and less easily prey on black moths. C) The moths changed their coloration to match their habitat as a response to increases in birds that preyed on the moths. D) Birds evolved to become better predators of the speckled moths since there were more of them available as a food source. E) Black moths migrated into the habitat while speckled moths migrated out to decrease their chances of becoming prey for birds.

B) Speckled moths declined and darker variants rose in numbers, as birds could more easily prey on speckled moths and less easily prey on black moths.

Which of the following is an issue that requires data from biological studies in order to make wise public policy decisions? A) Whether it is appropriate to invoke evening curfews to control crime B) Whether the use of fossil fuels should be regulated C) Whether rank-choice voting should be implemented in national elections D) Whether the minimum age for voting should be lowered E) Whether prayer should be allowed in public schools

B) Whether the use of fossil fuels should be regulated

Fruit flies have a heart that beats rhythmically and continues to beat normally in an open, partially dissected preparation. This has allowed biologists to test the direct effects of neurotransmitters and various pharmaceuticals on heart rate and rhythm. Could these studies be useful to medical studies of the human heart? Why or why not? A) No, because work carried out in a laboratory setting would not be applicable to human medical science. B) Yes, because all life on Earth is related by descent from a common ancestor, shares a genetic code, and consists of similar biochemical building blocks. This allows much of the knowledge derived from a model organism, such as the fruit fly, to be generalized to humans. C) Yes, because all organs with similar functions have similar anatomies, so the anatomy of the human heart will be the same as the anatomy of the fruit fly heart. D) No, because humans are eukaryotes and insects are prokaryotes, so organ processes in the two groups differ in too many ways. E) No, because the biology of fruit flies is unrelated to anything found in humans.

B) Yes, because all life on Earth is related by descent from a common ancestor, shares a genetic code, and consists of similar biochemical building blocks. This allows much of the knowledge derived from a model organism, such as the fruit fly, to be generalized to humans.

A population differs from a community in that a community A) is synonymous with an ecosystem. B) includes many species. C) is individuals of the same species that interact with each other. D) consists of just one species. E) includes the abiotic environment.

B) includes many species.

A cell A) is never an entire organism. B) is the fundamental unit of life. C) is always prokaryotic. D) is found only in plants and animals. E) always contains a nucleus.

B) is the fundamental unit of life.

Scientists postulate that the enclosure of complex proteins and other biological molecules by membranes resulted in the first cells with the ability to A) photosynthesize. B) reproduce. C) differentiate. D) carry out aerobic respiration. E) live in nonaqueous environments.

B) reproduce.

For a hypothesis to be scientifically valid, it must be _______, and it should be possible to _______ it. A) testable; prove B) testable; reject C) controlled; prove D) controlled; reject E) testable; control

B) testable; reject

In the scientific method, a hypothesis is A) formulated solely by speculation. B) the basis for making predictions. C) a final answer to a question. D) an alternative to an experiment. E) formulated by statistical analysis of data.

B) the basis for making predictions.

Among the techniques used for determining the relationships between living organisms, the one that provides the most precise data compares A) the fossil record to today's living organisms. B) the genomes of living organisms. C) the patterns of embryological development of living organisms. D) anatomical features of fossils. E) anatomical features of living organisms.

B) the genomes of living organisms.

Which question cannot be answered by means of the method that uses a hypothesis and then a prediction? A) Do red roses bloom earlier than yellow roses? B) Are bees more attracted to red roses than to yellow roses? C) Are red roses more beautiful than yellow roses? D) Are red roses more susceptible to mildew than yellow roses? E) Why are red roses red?

C) Are red roses more beautiful than yellow roses?

Evidence from which type of data supports the common origin of all life on Earth? A) Atmospheric oxygen levels B) Age of oldest fossil C) DNA structure D) Cellular specialization E) Mitochondrial function

C) DNA structure

Suppose that you are working in a research lab investigating the nature of multicellularity. Which evidence could you gather from two different types of cells obtained from an adult multicellular animal to show that they are specialized? A) Presence of cell machinery needed to synthesize proteins B) Ability to take in nutrients C) Differences in genes being expressed D) Changes in the total amount of energy produced E) Responses of cells to waste buildup

C) Differences in genes being expressed

A fungus species is observed to undergo asexual reproduction at some times and sexual reproduction at other times. A researcher hypothesizes that the nutrient levels available to the fungus may be responsible for this effect. Which data could be used to test this hypothesis? A) Compare the genome of a mutant that is not able to switch from asexual to sexual reproduction to the genome of the normal fungus. B) Observe the sexual behavior of the fungus grown in a laboratory under various conditions such as pH, temperature, and water availability. C) Find samples of the fungus growing in the wild, record their reproductive behavior, and collect samples of the substrate they are growing on for chemical analysis. D) Collect information from cells about which genes are being expressed under the two types of reproductive behaviors. E) Grow fungi on high levels of nutrients in the lab, and observe reproductive behavior before and after adding additional nutrients.

C) Find samples of the fungus growing in the wild, record their reproductive behavior, and collect samples of the substrate they are growing on for chemical analysis.

Suppose fish caught at one location in a bay are tagged with simple, numbered, plastic tags. Which kind of information can a scientist gain if she catches one of these fish in another bay, distant from the first? A) The route it took before it was caught B) How far it can swim C) How far it swam D) Whether it was chased by a predator fish E) How deep it swam

C) How far it swam

Which is the oldest example of a human application of biological principles? A) Antibiotic production B) Vaccinations C) Plant breeding techniques D) Molecular genetic technologies E) Stem cell therapies

C) Plant breeding techniques

Which of the following is a feature of scientific hypotheses? A) They are not based on observations. B) They do not make predictions. C) They can be tested by experimentation. D) They cannot be tested by observational analysis. E) They cannot be falsified.

C) They can be tested by experimentation.

A research group hypothesizes that diet influences the distribution of bacterial species inhabiting the human digestive system. The researchers define two populations with very different diets—one in England and another in Africa—for sample collection. They take fecal samples from each group and measure the percentage of each species of bacteria present in the samples. How is this investigation classified, and why? A) This investigation is a controlled investigation because controlled methods were used for the collection and analysis of fecal samples. B) This investigation is a controlled investigation because it was carried out using defined study populations. C) This investigation is a comparative study because it compares a characteristic of two different groups that could be influenced by many variables. D) This investigation is a comparative study because it tests a hypothesis that was formulated by comparing the diets of two populations. E) This investigation is both a controlled and comparative study because it controls all but one variable influencing two study groups and then compares how that variable differs.

C) This investigation is a comparative study because it compares a characteristic of two different groups that could be influenced by many variables.

A researcher conducting a field study records the number of eggs laid by female wood ducks in a region over several breeding seasons. The researcher also records observations of wood duck mating and nesting behavior. The measurements of egg numbers constitute A) a controlled experiment. B) qualitative data. C) data that can be subjected to statistical methods of analysis. D) the conclusion to an experiment. iE) nformation about evolutionary change in the birds over a breeding season.

C) data that can be subjected to statistical methods of analysis.

Peeling skin syndrome is a disease in which outer skin tissue peels off in large sheets in affected individuals. This disease has a genetic basis. Research has identified that patients with this disease produce a nonfunctional protein. This protein normally becomes embedded in skin cell membranes and functions in adhesion between cells to hold them together to stabilize skin tissue. Continued investigation into this disease would likely focus on _______ the gene encoding the nonfunctioning adhesion protein in affected patients. A) duplicating B) turning off C) locating the mutation in D) increasing the expression of E) removing

C) locating the mutation in

Medical researchers interested in finding effective treatments for human diseases often use _______ in their work. The reason for this is that it is unethical to do certain kinds of experiments on humans, and so another organism that has characteristics similar to those of humans is used _______. A) fungi; as an easily obtainable organism B) archaea; in comparative experiments C) mice; as a model system D) Arabidopsis; for comparisons Chlorella; in controlled experiments

C) mice; as a model system

Many of the microbial organisms that are periodically epidemic in human populations have . A) long generation times and high mutation rates. B) long generation times and low mutation rates. C) short generation times and high mutation rates. D) short generation times and low mutation rates. E) long generation times and no mutations.

C) short generation times and high mutation rates.

Scientists estimate that for more than _______ years after cells originated, all organisms consisted of one cell. A). 2,500 B). 250,000 C). 2.5 million D). 2.5 billion E). 2.5 trillion

D) 2.5 billion

Which governmental committee should rely heavily on information concerning biodiversity in order to make wise decisions? A) Judiciary B) Rules and Administration C) Veterans' Affairs D) Energy and Natural Resources E) Financial Services

D) Energy and Natural Resources

Which is a reason to use statistics to evaluate data? A) It facilitates the exclusion of data that do not fit your hypothesis. B) It enables you to predict experimental results. C) It provides a way for proving that your hypothesis is correct. D) It accounts for variation in scientific measurements. E) It makes it possible to avoid having to consider the null hypothesis.

D) It accounts for variation in scientific measurements.

According to current thinking about the rise of life on Earth, which two critical types of molecules evolved in what order before the first primordial cells formed? A) Carbohydrates followed by lipids B) Oxygen followed by ozone C) Enzymes followed by DNA D) Nucleic acids followed by proteins E) Photosynthetic pigments followed by amino acids

D) Nucleic acids followed by proteins

Which sequence gives the correct ordering of levels from smallest to largest? A) Ecosystem, community, population, organism B) Organism, community, population, ecosystem C) Community, ecosystem, organism, population D) Organism, population, community, ecosystem E) Population, organism, ecosystem, community

D) Organism, population, community, ecosystem

An international commission drew a line down the middle of the Atlantic Ocean with the intent of allowing western populations of bluefin tuna to recover from ocean fishing. Which statement about this effort is true? A) Bluefin fishing was restricted in both the western Atlantic Ocean and eastern Atlantic Ocean. B) Bluefin tuna populations recovered in the western Atlantic Ocean. C) Tracking data revealed that a population of bluefin tuna feeds on only one D) The policy had little effect on bluefin populations, as the eastern and western Atlantic populations freely mix. E) It was initially assumed that bluefin tuna populations did not have geographically separated feeding grounds.

D) The policy had little effect on bluefin populations, as the eastern and western Atlantic populations freely mix.

A key point in Darwin's explanation of evolution is that A) the biological structures most likely to be inherited are those that have become best suited to the environment through constant use. B) extinction is nature's way of weeding out undeserving organisms. C) all mutations that occur are those that will help future generations fit more successfully into their environments. D) any trait that confers even a small increase in the probability that its possessor will survive and reproduce will be favored and will spread through the population. E) genes change to help organisms cope with problems encountered within their environments.

D) any trait that confers even a small increase in the probability that its possessor will survive and reproduce will be favored and will spread through the population.

Ozone is important to life on Earth because it A) can be used in place of oxygen. B) is toxic to all forms of life. C) acts as a disinfectant. D) blocks much ultraviolet (UV) radiation. E) provides energy to some basic forms of life.

D) blocks much ultraviolet (UV) radiation.

Homeostasis involves the maintenance of a A) constant rate of natural selection. B) variable internal environment. C) variable rate of natural selection. D) constant internal environment. E) constant external environment.

D) constant internal environment.

During development, cells in a human embryo divide and take on varying shapes and functions. For example, some embryonic cells divide and become osteoclasts while others become osteoblasts, two types of cells that make up bone. This process is called A) genetic drift. B) cellular autonomy. C) evolution. D) differentiation. E) determination.

D) differentiation.

An individual organism A) cannot do biological work. B) can survive without nucleic acids. C) can evolve. D) must be able to regulate its internal environment. E) always contains more than one cell.

D) must be able to regulate its internal environment.

Comparative experiments are designed to answer questions that require A) experimental groups and control groups. B) a final, definitive answer. C) the collection of qualitative data. D) observation and comparison rather than controlled variables. E) little or no data collection.

D) observation and comparison rather than controlled variables.

When applying biology to public policy, A)the recommendations of scientists are always followed. B) there are no ethical issues involved. C) the economic issues of a policy are not considered. D) several countries may be involved. E) the correct course of action is always evident.

D) several countries may be involved.

Which does not result from a scientific investigation? A) Formulation of new questions that result in additional experimentation B) Refinement of the experimental design C) Use of statistical tests to evaluate the significance of the results D) Experiments repeated and verified by others E) A conclusion based on the investigator's opinion

E) A conclusion based on the investigator's opinion

Which represents a correct ordering of the levels of complexity at which life is studied, from most simple to most complex? A) Community, population, organism, organ, tissue, cell B) Tissue, organ, cell, population, organism, community C) Cell, tissue, organ, population, organism, community D) Cell, organ, tissue, organism, population, community E) Cell, tissue, organ, organism, population, community

E) Cell, tissue, organ, organism, population, community

A researcher poses the hypothesis that plants grow tallest under a full spectrum of visible light. The researcher runs an experiment in which she plants seeds of the same plant species in pots and places different groups of pots under different lighting conditions. Group 1 receives the full spectrum of visible light, while groups 2 through 6 receive narrow ranges of visible wavelengths of light. All lighting conditions are at the same intensity. The researcher observes that the plants growing tallest are those exposed to blue light. After making these observations, which step is she most likely to carry out next? A) Run a control trial to be sure that a valid conclusion can be made based on the results. B) Design a follow-up experiment to change soil type and water conditions simultaneously as tests of these variables on plant growth. C) Repeat the experiment at a different level of light intensity. D) Discard her question that asks what factors influence plant growth and why. E) Discard her original hypothesis and formulate a new one.

E) Discard her original hypothesis and formulate a new one.

Which set of outcomes is most likely if cell processes become unregulated and homeostasis is lost? A) Differentiation and cell specialization B) Mutation and genetic change C) Metabolic readjustment and healing D) Adaptation and survival E) Malfunction and disease

E) Malfunction and disease

A biologist hypothesizes that keeping mice on a restricted diet with minimal calories will increase their aggression. The biologist designs an experiment in which 100 mice are to be housed in individual cages under similar conditions and diets. He then plans to place pairs of mice together in the same cage to observe their interactions. What is true about this study design? A) The study is well designed since it uses a large sample of mice. B) The study is unnecessary because the results are obvious. C) The study is flawed because the hypothesis is not testable. D) The study includes too many variables. E) The study is not controlled.

E) The study is not controlled.

Nutrient molecules acquired by animals A) are a source of matter but not energy for the animals. B) are all broken down outside of cells. C) are all synthesized by the animals' cells. D) do not play a role in the synthesis of complex molecules. E) are broken down to produce usable energy for cellular processes.

E) are broken down to produce usable energy for cellular processes.

A public policy committee trying to decide _______ would benefit most from the knowledge a biologist could provide. A) if a bridge across a river should be repaired B) how many signatures a candidate should require in order to be put on a ballot C) which organizations in a town should be tax-exempt D) if a town should invest in opening a medical clinic E) if a shopping center should be built close to a marsh

E) if a shopping center should be built close to a marsh

Diabetes type 1 is a disease in which the hormone insulin is not produced. Insulin promotes the uptake of glucose by cells, so when insulin is absent, cells do not take up glucose from the blood. This causes elevated blood glucose levels and leaves cells starved for an energy source. Injecting insulin as needed by these patients is a solution that allows their bodies to A) prevent passing of the disease to someone else. B) cure themselves of the disease. C) digest their food. D) increase circulation to all their organs. E) maintain a state of homeostasis.

E) maintain a state of homeostasis.

Darwin referred to the differential reproductive success of individuals with particular variations as A) evolution. B) artificial selection. C) inheritance of acquired characteristics. D) the cell theory. E) natural selection.

E) natural selection.

Biologists have discovered A) about three-quarters of the species that inhabit Earth. B) almost all of the species that inhabit Earth. C) about half of the species that inhabit Earth. D) a small percentage of the species that inhabit Mars. E) only a small percentage of the species that inhabit Earth.

E) only a small percentage of the species that inhabit Earth.

The early organisms that produced the first oxygen gas in Earth's atmosphere were A) completely unlike modern organisms. B) aerobic eukaryotes. C) aerobic prokaryotes. D) anaerobic eukaryotes. E) photosynthetic prokaryotes.

E) photosynthetic prokaryotes.

The organisms that produced the oxygen gas in Earth's early atmosphere were A) aerobic prokaryotes. B) anaerobic eukaryotes. C) completely unlike modern organisms. D) aerobic eukaryotes. E) photosynthetic prokaryotes.

E) photosynthetic prokaryotes.