Bio 102 Exam 3 – Flashcards
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A person's skin tone is not caused by _______.
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D. whether or not the person is related to the "mitochondrial Eve" or the last common female ancestor
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Which of the following statements is not a correct relationship about how the UV light environment affects humans?
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E. In a high UV-light environment, skin color is more likely to be lighter.
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The darker the skin of a person, the more likely that some of their ancestors ___________.
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D. Were from a geographical area closer to the equator
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Hominids evolved under natural selection pressures that selected for certain traits that conferred an advantage to individual consider the following list of traits. Choose the answer that correctly orders the evolutionary pattern of hominid traits. 1. Hominids lost their excessive body hair and gained more sweat glands. 2. Hominids evolved dark and hairless skin. 3. Hominids covered in thick hair and had light skin.
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C. 3, 1, 2= Hominids covered in thick hair and had light skin, hominids lost their excessive body hair and gained more sweat glands, and hominids evolved dark and hairless skin.
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Why is there so much variation in skin coloration?
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E. all of the above contribute to the wide variation of human skin coloration; this occurred because humans underwent natural selection that resulted in traits that conferred advantages to humans becoming fixed in populations, this occurred because skin coloration results in different advantages depending on the levels of sun in the region, this occurred because alleles that are harmful in one environmental context may be beneficial in another, this occurred because humans are found in areas that range from high UV light environments to low UV light environments.
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Research into evolution of skin color has resulted in a complete hypothesis explaining why skin color varies geographically. Which of the following is not a result of this research?
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D. The weaker the ultraviolet light, the darker the skin, because people with light skin are more vulnerable to folate destruction than darker-skinned people
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Scientists have found that _____
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E. genetic diversity decreased as early humans migrated away from Africa and founded new populations
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Scientists have studied patterns of mitochondrial DNA to determine where humans first evolved and how they spread. Humans inherit their mitochondrial genes only from their mothers. Why aren't a father's mitochondrial genes passed to offspring?
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B. Sperms do not contribute their mitochondria to the zygote
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Scientists used mitochondrial DNA to investigate patterns of human evolution. Which of the following is a result of this research?
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B. all humans are related to a single female ancestor
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Which of the following is not a way scientists used mitochondrial DNA to determine where humans first evolved and how they spread?
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E. both B and C are not ways scientists used mtDNA to infer human evolutionary patterns; Scientists constructed an evolutionary tree based on paternal tDNA to trace human ancestry back to a single female, and scientists extracted mtDNA from Homo erectus fossils and compared them to modern humans
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What are characteristics of mitochondrial DNA that made it a suitable choice for studying human evolutionary patterns?
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B. Mutations from mothers are passed to offspring without recombination with paternal mtDNA
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Researchers have studied human genetic relatedness and the distribution of certain traits to infer patterns of human migration. Their studies show that humans who migrated northward from Africa had descendants with ________.
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D. A greater risk of folate deficiency
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Which of the groups below contains a species that is not a hominid?
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D. Humans, chimpanzees, Homo melanin, Homo erectus
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Scientists rely on evidence from the fossil record to determine how and when events in human evolution occurred. Which of these major milestones in human evolution is not correctly dated?
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B. the most recent common ancestor of chimpanzees and humans was Ardipithecus ramidus, which lived 4.4 million years ago
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Which of the following is not something found in the fossil record that has been used by scientists to understand human evolutionary patterns?
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A. genetic material extracted from a 4.4 million year old fossil of Ardipithecus ramidus
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The fossil remains Ardipithecus Ramidus showed that ____
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B. the ability to walk upright preceded the evolution of a larger brain
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Variations of human skin tone is driven by
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E. all of the above; DNA variation in the population, natural selection, inheritance and survival, and adaptations over time
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In a person of very dark skin tone, it is expected that their melanocytes produce
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B. Very large quantities of melanin pigment
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In the absence of melanin production, a person would
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D. have albinism
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Humans have been a species for
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B. 200,000 years
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Skin color is determined by the amount of ____ a person has in their skin
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D. melanin
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Who is mitochondrial eve?
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A. an African maternal ancestor of all humanity today
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What fact was used to determine that mitochondrial eve is every human's ancestor?
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C. only females pass on mitochondrial genes in the egg cell
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Mitochondrial eve can be traced back to
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D. Eastern Africa, 150-200,000 years ago
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How do we know mitochondrial eve is every human's ancestor
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C. global comparison of human mitochondrial and nuclear sequences
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Which of the following statements about human evolutionary history is true?
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A. All modern humans can trace their ancestry to one female
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Which of the following statements about mitochondrial eve is true?
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B. mitochondrial Eve lived about 200,000 years ago
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The ancestral population of humans lived in
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A. Africa
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The oldest known fossils of modern humans found in Eastern Africa date to
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C. 160-195,000 years ago
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Scientists use genetics to trace the evolution and migration of humans. How do scientists know which populations are older than others?
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C. members of older populations have more genetic variability
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Anatomically modern humans
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A. left Africa 150-200,000 years ago arrived in both Western Europe and Australia around 40,000 years ago-- before they arrived in North or South America
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Hominids include
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E. living and extinct great apes, humans, orangutans, chimpanzees, and gorillas
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Chimpanzee and human divergence occurred
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A. 6 million years ago
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The first tool users were members of genus
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B. Austrolopithecus
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All of the following statements regarding ecosystems are correct EXCEPT _______.
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D. sunlight and water are good examples of living components of an ecosystem
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Which of the following ecological definitions is incorrect?
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D. A community is made up of biotic and nonliving components
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Imagine a system where a finch feeds on thistle seeds and the finch population size is linked to the productivity of the thistle, and the thistle population size is related to foraging pressure of the finch population. This is the example of population dynamic of the ________ level.
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B. Community
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Ecologists study organisms at a number of levels with different numbers of components. Which of the following correctly orders these levels, from smallest to largest?
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A. individual, population, community, ecosystem
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Which of the following is not an example of something that ecologists would generally study?
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B. How the mitochondria of a mouse function in its cell
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Ecologists often study the spatial distribution of animals. Which of these descriptions does not match one of the common distribution patterns?
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C. Uniform: moose are highly territorial creatures and more around an island habitat in large groups
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Why are truly random distributions rare in nature?
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E. a, b, and c are all reasons why random distributions are rare; Individuals of a particular species often need certain types of conditions to survive and grow, so more individuals are found in these areas, Resources are unevenly distributed across most landscapes, Many species have social behaviors that promote clusters of individuals for increasing foraging success or for predator avoidance
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All of the following can be advantages of a clumped distribution pattern EXCEPT _____________.
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A. it allows individuals to maximize space between them
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Which of the following is TRUE of distribution patterns in nature?
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D. a and b are true, but not c
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Carrying capacity is NOT the point _________.
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C. Where additional resources are available only to individuals that immigrate into the population
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Once the carrying capacity of an environment is reached, the population generally ________.
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D. all of the above
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Growth rates are ________.
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E. A and B; the difference between birth and death rates in a population, and influenced by immigration and emigration patterns
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Which of the following events of conditions to a density independent factor that could influence population growth?
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C. a volcanic eruption that covers an island in a layer of lava
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When moose first arrived on Isle Royale and found a habitat without predators, the moose population _______.
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E. all of the above
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How have warmer than normal climate conditions affected moose population on Isle Royale?
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D. A and C
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Population dynamics are influenced by birth and death rates. Which of the following are not factors that can cause death for wolves on Isle Royale?
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C. Warmer temperatures have caused tick populations that feed on wolves to increase dramatically, which causes wolves to lose blood and increase their hunting abilities
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By studying the data collected from Isle Royale, ecologists have discovered that a large wolf population correlates to vigorous tree growth. Which of the following best explains this pattern?
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E. A and C
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Which of the following is not a biotic factor affecting population growth of moose on Isle Royale?
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A. Summer temperatures
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The island of Guam traditionally has not had any snakes that prey on birds; however, brown tree snakes that prey upon birds were introduced. Use your knowledge of wolf-moose population dynamics to determine what happened to the population dynamics of birds and the new snakes on Guam. Which of the following is probably not one of the results of the snake introduction? (NOT ON TEST)
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E. all of the above are probably results of the snake introduction (NOT ON THE TEST)
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The total number of wolves inhabiting Isle Royale is defined as a __________.
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C. population
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The term ________ describes the interacting populations (eg. moose and ticks) within an ecosystem
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B. community
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A report based on the interactions of wolves, moose, ticks, and trees on Isle Royale describes a(n) ___________.
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B. community
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The term __________ describes all interacting species such as moose ticks and wolves as well as their surrounding environment of trees, vegetation, and climate
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D. Ecosystem
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A report that documents all the species (plants and animals) in an area but does not include the environment describes
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C. a community
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In predator-prey relationships, scientists are interested in which level of organization
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D. a community
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A researcher who investigates how flooding affects the different populations on an island is most interested in which level of organization?
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A. ecosystem
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Which would NOT be examined in the study of community
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D. rainfall and drought
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Butterflies eat flower nectar and birds eat butterflies. The butterflies, flowers, and birds constitute a(n)
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C. community
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The ocean, sand, rocks, plants, seagulls, and invertebrate represent a(n)
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D. ecosystem
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Which behavior would most likely result in a uniform distribution pattern?
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D. territorial and nesting behaviors in birds
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A flock of birds represents a __________ distribution pattern, while birds on a power line with six inches of space between each bird represents a ___________ distribution pattern
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D. clumped; uniform
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In a geographically isolated habitat, DNA analysis of a population can document
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E. all of the above; DNA interbreeding, loss of genetic diversity, identification of individuals, by DNA profiling, and changes in allele frequency of a gene
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When a population reaches its carrying capacity, its growth rate will
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C. slow and remain near zero
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A population limited by environmental factors would be an example of
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A. logistic growth
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The growth rate of a population is calculated from the ______ for that population
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B. difference between births and deaths
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Which of the following conditions would lead to the fastest population growth?
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C. birth rate > death rate; immigration > emigration
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A few years after a predator species population decreases, the ______________
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E. prey population will increase
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Removal of a predator from an ecosystem may do all of the following, EXCEPT
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B. allow prey populations to remain above carrying capacity
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Which is NOT a biotic factor that could affect a population?
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C/E?? Water availability
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Which is a density-dependent factor?
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A. predation
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Which is a density-independent factor?
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B. drought
