BIO152 Term Test 1 10 of 10

Transcription

1 1. A scientific theory is a. An observation leading to a strong hypothesis. b. A conjecture, idea or hypothesis of how something works or how it came to be. c. An educated guess about something; it is the starting point to find the real answer. d. An explanation based on many lines of evidence, tested in many ways, and provides valid predictions. 2. Which of the following is NOT a feature of scientific hypotheses? a. They make predictions. b. They are based on observations. c. They can be tested by experimentation. d. They can be tested by observational analysis. e. They are usually proven true. 3. What is a null hypothesis? a. What should be observed in an experiment if a hypothesis is correct b. A proposed explanation for a scientific phenomenon c. An alternative possibility in the event that the explanation being tested does not apply. d. An experiment to test for factors that might influence an experiment s outcome 4. Identifying evolution in action: Identify which scenario described below is most likely to NOT result in evolution. a. Insecticide is applied to a population of mosquitoes; most of which are initially killed upon exposure to the chemical; but a few survive and reproduce. b. A man spends many hours in the gym exercising and is able to increase his body weight, muscle mass, and strength, which makes him feel healthier. c. Some male individuals in a population of kangaroos are born with larger front paws and longer forearms. This gives them an advantage when boxing other males to compete with them for mating with females. d. Toxic levels of heavy metals are dumped as waste from coal mines. Initially, no plants will grow on the waste dump; but eventually some grasses begin to colonize the dump sites and reproduce. e. A hurricane blows a small group of beetle-eating birds to an island in the ocean. Although the new environment lacks the beetles that the birds normally eat, it has various types of hard-shelled nuts. Some of the birds have larger, more pointed beaks and are able to crack the nuts open.

2 5. Limpets growing in the ocean in the intertidal zone where they experience heavy wave action, are more conical than individuals of the same species growing in the subtidal zone where they are protected from waves. Individuals moved from the high intertidal zone to the subtidal zone, add new growth, which produces a flatter, subtidal shape. This experiment suggest that the difference in shape is a. Environmentally-induced and likely an example of acclimitization b. Environmentally-induced and likely an example of natural selection c. Due to genetic variation which will result in natural selection based on shape. d. Cannot be answered without more information. 6. What is an important feature of sexual reproduction? Sexual reproduction a. is unique to plants and animals. b. produces variation through genetic recombination. c. uses mitosis to produce gametes. d. is more efficient than asexual reproduction. e. is always associated with selective mating. 7. Selection acts on variation; however, evolution depends on variation in the population. a. phenotypic; genetic b. genetic; phenotypic c. genetic; environmentally-induced d. environmentally-induced; phenotypic e. environmentally-induced; genetic 8. Doctors have been treating patients infected with the organism that causes the disease malaria with ZAPIT. However, they noticed that the effectiveness of ZAPIT has been decreasing steadily for a number of years as the organism becomes more resistant to the drug. This phenomenon is an example of what type of selection? a. Stabilizing b. Disruptive c. Directional d. No selection 9. Which one of the following predictions follows from the sexual selection hypothesis for why giraffes have long necks? a. In contests over females, the best-nourished male should always, or almost always, win. b. In contests over females, the male with the longest neck should always, or almost always, win. c. In natural populations, female neck length should decline over time. d. Young males that are given extra amounts of high-quality food should grow particularly long, strong necks.

3 10. Which of the following statements describes similarities between natural and sexual selection? a. Individuals with certain variations have more surviving offspring. b. Traits that are selected are beneficial to survival of both sexes; these traits are genetic and inherited. c. Selection operates on all individuals of the same species. d. Selection operates on both sexes equally. 11. If a population is well adapted to its current environment, and if the environment remains constant, what type of reproductive strategy will be most successful? a. Sexual reproduction b. Asexual reproduction c. Both will be equally successful d. Neither will be successful over long periods of time. 12. For a biologist studying a small fish population in the lab, which Hardy-Weinberg condition is easiest to meet? a. no selection b. no genetic drift c. no gene flow d. no mutation e. random mating Question 13 & 14 Researchers studying a small milkweed population note that some plants produce a toxin and other plants do not. They identify the gene responsible for toxin production. The dominant allele (T) codes for an enzyme that makes the toxin, and the recessive allele (t) codes for a nonfunctional enzyme that cannot produce the toxin. Heterozygotes produce an intermediate amount of toxin. The genotypes of all individuals in the population are determined (see chart) and used to determine the allele frequencies in the population. Genotype Frequencies Allele Frequencies TT Tt tt T t (expected) Is this population in Hardy-Weinberg equilibrium? a. yes b. No; there are more heterozygotes than expected. c. No; there are more homozygotes than expected. d. More information is needed in order to answer this question.

4 14. The researchers had already noted that negligible mutation and migration existed in this milkweed population, and the butterflies that pollinate these plants are not affected by the toxin. Which of the following would be a logical conclusion about this milkweed population based on your answer to the question above? a. There is little of no genetic drift or selection. b. There is either a heterozygote advantage or inbreeding depression. c. There is either directional selection or sexual selection. d. There is either disruptive selection or genetic drift. e. There is either stabilizing selection or gene flow. 15. Currently the only predators of Galápagos marine iguanas are Galápagos hawks. Iguana body size is not correlated with risk of hawk predation, although small iguanas can sprint faster than large iguanas. If predators (e.g., cats) that preferably catch and eat slower iguanas are introduced to the island, iguana body size is likely to in the absence of other factors; the iguanas would then be under selection. a. increase; directional b. increase; disruptive c. decrease; directional d. decrease; stabilizing e. stay the same; stabilizing 16. Three-spined stickleback fish (Gasterosteus aculeatus) show substantial heritable variation in gill raker length. Fish caught in open water tend to have longer gill rakers and eat different foods than do those caught in shallower water. Longer gill rakers appear to function better for capturing open-water prey, while shorter gill rakers function better for capturing shallow-water prey. Which of the following types of selection is most likely to be found in a lake with a high density of these fish? a. directional selection b. stabilizing selection c. disruptive selection d. sexual selection e. no selection 17. Male turkeys have a snood, which is a flap of skin that hangs across their beak. Snood length is negatively correlated with parasite load (e.g., males with longer snoods have fewer parasites), and females prefer to mate with long-snooded males. This is an example of: a. the fundamental asymmetry of sex b. sexual selection via female choice c. sexual selection via male-male competition d. a genetic marker

5 18. In some jacana species, males take care of the eggs and young, and females compete for territories against one to several males. Female jacanas are significantly larger than males. Which of these statements would you predict to be true of this bird species? 1.Male jacana fitness is primarily limited by ability to take care of eggs and raise young. 2.Female jacana fitness is limited by the number of males with which they can mate. 3.Variation in reproductive success should be greater in male jacanas than in females. 4.Variation in reproductive success should be greater in female jacanas than in males. 5.Males and females have equal variation in reproductive success. a. 1 and 3 b. 2 and 4 c. 1, 2, and 3 d. 1, 2, and 4 e Male reproductive success, measured as the number of offspring surviving to adulthood (pupating), is found for two closely related beetle species and graphed below. Which of these statements would you expect to be true of sexual dimorphism in the two species? a. Species A should have greater sexual dimorphism than species B. b. Species B should have greater sexual dimorphism than species A. c. Species A and B should have about equal amounts of sexual dimorphism. d. Neither species should show any sexual dimorphism. 20. In 1986 a nuclear power accident in Chernobyl, USSR (now Ukraine) led to high radiation levels for miles surrounding the plant. The high levels of radiation caused elevated mutation rates in the surviving organisms, and evolutionary biologists have been studying rodent populations in the Chernobyl area ever since. Based on your understanding of evolutionary mechanisms, which of the following most likely occurred in the rodent populations following the accident? a. Mutation by itself led to major changes in rodent physiology over time. b. Genetic drift followed by mutation led to increased genetic variation. c. Mutation caused genetic drift and decreased fitness. d. Mutation caused the fixation of new alleles.

6 21. Guppies are small fish found in streams in Venzuela. Male guppies are brightly coloured, but the amount of colouring varies depending on the number and types of predators in the ponds. If female guppies prefer to mate with males having colourful body patterns despite the risk of predation for colourful males, what hypothesis (es) would best explain the continuation of bright colouration in the males? a. Changing environment hypothesis b. Natural selection c. Bad gene hypothesis d. Good genes e. All of the above f. a and d g. b and c 22. In what sense is the Hardy-Weinberg principle a null hypothesis, similar to the control treatment in an experiment? a. It defines what genotype frequencies should be if nonrandom mating is occurring. b. Expected genotype frequencies can be calculated from observed allele frequencies and then compared with the observed genotype frequencies. c. It defines what genotype frequencies should be if natural selection, genetic drift, gene flow, or mutation is occurring and if mating is random. d. It defines what genotype frequencies should be if evolutionary mechanisms are not occurring.

7 23. Which of these statements most fully characterizes the fundamental asymmetry of sex? a. Female fitness is limited most by the ability to get resources for producing eggs and rearing young, while male fitness is limited by the ability to attract females. b. Female fitness is limited most by the ability to attract males, while male fitness is limited by the ability to get resources for provisioning the female. c. Female fitness is limited most by the ability to get resources for producing eggs and rearing young, while male fitness is limited by the ability to get resources for provisioning the female. d. Female fitness is limited most by the ability to attract males, and male fitness is limited by the ability to attract females. 24. Which of the following is NOT true about sexual selection and its consequences? a. In a species with strong sexual selection, female choice of mates benefits her ability to survive and the ability of her offspring to reproduce. b. Bright colours and extravagant ornaments in males are often the result of natural selection. c. Sexual dimorphism tends to be absent when there is no competition for mates among members of the same sex. d. Sexual dimorphism cannot be easily explained by ordinary natural selection because males and females of a species generally face the same environmental conditions. e. Females are generally expected to be choosy about the males they mate with. 25. Recall the chili pepper experiment that tested whether capsaicin acts as a deterrent to predators. What was the rationale for studying the eating habits of the curve-billed thrasher a known seed disperser? a. The thrasher should eat mild and hot chilies in order for the chilies seeds to be dispersed. b. The thrasher should eat only the mild chilies, because the hot ones could cause damage to its mouth. c. The thrasher should eat only the hot chilies, because it is capable of finding water very quickly. d. The thrasher should not eat any of the chilies, because it would destroy the chilies seeds.

8 The following experiments are used for questions 26 28: In 1668 Francesco Redi did a series of experiments on spontaneous generation. He began by putting similar pieces of meat into eight identical jars. Four jars were left open to the air, and four were sealed. He then did the same experiment with one variation: instead of sealing four of the jars completely, he covered them with gauze (the gauze will exclude the flies while allowing the meat to be exposed to air). In both experiments, he monitored the jars and recorded whether or not maggots (young flies) appeared in the meat. 26. What hypothesis was being tested in the initial experiment with open versus sealed jars? a. Spontaneous generation is more likely during the long days of summer. b. The type of meat used affects the likelihood of spontaneous generation. c. Maggots do not arise spontaneously, but from eggs laid by adult flies. d. Spontaneous generation can occur only if meat is surrounded by air. 27. In both experiments, flies appeared in all of the open jars and only in the open jars. Which one of the following statements is correct? a. The experiment was inconclusive because Redi used only one kind of meat. b. The experiment was inconclusive because it did not run long enough. c. The experiment supports the hypothesis that spontaneous generation occurs in rotting meat. d. The experiment supports the hypothesis that maggots arise only from eggs laid by adult flies. 28. Redi s first experiment compared maggot appearance in jars which were open and sealed with a cover. His second experiment compared open and gauze-covered. Which of the following statements is NOT a reasonable, plausible hypothesis for what is being tested in the second experiment. a. Adult flies are attracted to rotting meat by the smell. b. Maggots can appear in rotting meat only if they are protected from predatory wasps. c. If maggots do not appear in sealed jars, it is because they require fresh air to grow. d. Maggots can appear in the rotting meat if the jars are not sealed correctly. 29. What does the biological term evolution mean? a. The strongest individuals produce the most offspring. b. The characteristics of an individual change through the course of its life, in response to natural selection. c. The characteristics of populations change through time. d. The characteristics of species become more complex over time.

9 30. Which of the following is a condition needed for natural selection to occur? a. Random mating must occur. b. The population must be large for natural selection to occur. c. Humans select which individuals mate. d. Individuals within a population vary in their characteristics. 31. Which of the following explanations for change correctly expresses natural selection as the process for evolution. a. The widespread use of DDT in the mid-1900s put pressure on insect populations to evolve resistance to DDT. As a result large populations of insects today are resistant to DDT. b. Wide-scale use of DDT in the mid-1900s selected for any insects that carried the genes that made them resistant to DDT. These insects mated and passed on their resistance to their offspring c. Both statements are equally correct. d. Neither statement correctly explains insect resistance to DDT by natural selection. 32. Which of the following explanations for change correctly expresses natural selection as the process for evolution. a. Dinosaurs became extinct because they couldn t evolve fast enough to deal with climatic changes that affected their food and water supplies. b. Dinosaurs became extinct because their physiological and behavioural traits were too specialized and lacked enough variability to survive rapid changes. c. Both statements are equally correct. d. Neither statement explains dinosaur extinction by natural selection. Questions use Table 1 below Table 1 Comparison of male cat traits and their offspring NAME Tabby Chessy Tony Tiger Size 5 kg 4.8 kg 3 kg 4 kg # kittens fathered # Kittens surviving to adulthood Age at death(years) Comments Largest & Mated with the strongest most females Lost on family vacation; lived on the street 2 more years Died from infection after cat fight

10 33. Which cat contributed the most genes to the next generation? a. Tabby b. Chessy c. Tony d. Tiger e. Cannot be answered without more information. 34. Which cat is the fittest in evolutionary terms? a. Tabby b. Chessy c. Tony d. Tiger e. Cannot be answered without more information. 35. What is the key point in Darwin s explanation of evolution by natural selection? a. The biological structures most likely inherited are those that have become better suited to the environment through constant use. b. Mutations that occur are those that will help future generations fit into their environments. c. Slight variations among individuals significantly affect the chance that a given individual will survive in its environment and be able to reproduce. d. Genes change in order to help organisms cope with problems encountered within their environments. e. Extinction is nature s way of weeding out undeserving organisms.