Biology Chapter 16 Flashcards

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What is the most plausible explanation for why the male of most birds species have elaborate plumage and mating rituals?

A. sexual selection
B. natural selection
C. gene flow
D. genetic mutations



The recessive allele for sickle cell anemia is more prevalent in regions of Africa where malaria is prevalent, than it is in regions where there is no malaria.This is due to a

A. frequency dependent selection
B. Founder Effect
C. bottleneck effect
D. heterozygous advantage



Which of the following reflect(s) the likely of (a) gene mutation(s)?

A. fruit flies subjected to intense produce a wider array of variable offspring.
B. a chemical leaking from the surface of an old abandoned coal mine alters a regulatory gene so that a cricket nymph develops an extra set of eyes.
C. the bacteria that cause gonorrhea, a common sexually transmitted disease, have previously been killed by penicillin; however, after continuous usage of antibiotic, penicillin-resistant strains are now becoming prevalent.
D. radiation causes an alteration in a DNA nucleotide sequence, which is discovered when mapped, but which appears to be neither increasing nor decreasing in successive generations.



A population of organisms that reproduce asexually without gametes from other individuals will display more variation than a population that reproduces sexually. This results in a greater likelihood of the population evolving.



Which of the following is required for natural selection to occur in a population?

A. variation in the population
B. inheritance of variation through genetic differences
C. differential reproduction so that the more fir individuals have more offspring that survive to reproduce
D. accumulation of adaptive traits to that they increase in the population
E. all of the choices are required



The northern elephant seal was hunted almost to extinction during the 18th and 19th centuries. Less than 100 seals were left to contribute to the gene pool of their future generations. Since the early 20th century, the elephants seals have been protect by law in both the U.S. and Mexico. Over 100,000 seals now inhabit the western shores of North America, all related to the small population that survived the slaughter of hunters. Scientists fear the elephant seals may be more susceptible to disease and pollution due to a _____________

A. Founder Effect
B. Bottleneck Effect
C. disruptive type of selection
D. heterozygous advantage



If two adjacent populations of the same species show gene flow, then the two populations will

A. become isolated from each other
B. become more similar in their gene pools
C. adapt to different conditions and become separate
D. develop into different species



A certain species of butterfly varies in color from white to dark blue. The birds found in the same area feed on the white or lightly colored butterflies, leaving butterflies that are darkly colored. This may result in what type of selection?

A. directional selection
B. stabilizing selection
C. disruptive selection



An allele becomes the most common allele in a population by becoming the dominant allele.



The bottleneck effect is thought to be responsible for the loss of genetic variability in a species



The most common source of genetic variation in sexually reproducing organisms is

A. duplication of chromosomes
B. mutation
C. recombination of alleles through meiosis and fertilization
D. duplication of genes



In a population, the allele frequency for red flower color remained at 0.7 and the allele frequency for white flower remained at 0.3 for six generations. This _____ an example of a Hardy-Weinberg equilibrium in that __________

A. is, evolution did not occur
B. is not, evolution occurred
C. is, evolution occurred
D. is not, evolution did not occur



Which of the following would change the allele frequencies of a population?

A. DNA is stable from generation to generation and does not change, so allele frequencies do not change.
B. tall people in a population preferentially marry other tall people and do not marry people who are short or average height.
C. a population on an island remains isolated and no one leaves or moves onto the island.
D. All of the answer choices would change allele frequencies of a population.



While studying gull egg laying abilities a researcher noted that the birds laid an average of 7-9 eggs per clutch at the beginning of the study. After studying the population for 15 generations the researcher noted that the birds now laid an average of 3-4 eggs per clutch. What type of natural selection is occurring in the population of gulls?

A. stabilizing
B. directional
C. there is no selection occurring in this population
D. disruptive



Our domesticated honey bee-originally from Europe- is slow to sting, requires abundant flower nectar, gets up late in the morning, & store much honey but only produces enough new brood to swarm once a year. Because the European honey bee was performing poorly as a honey producer in South America, the African subspecies was imported in a breeding experiment. The African honey bee formed small nests, foraged earlier & on smaller nectar sources, produced less honey stores & more brood, swarmed four or five times a year, & was fast to sting. However, when the African queens escaped, the two populations interbred & the African genotype spread several hundred miles north each year. Surprisingly, a hundred miles behind the expanding range of the African honey bees, the European and hybrid stains died out and the bees were essentially 100 percent African. How would this be explained in evolutionary genetics terms?

A. gene flow is occurring between these subspecies but the African bee is 'ecologically better suited'
B. this is a natural consequence of the Hardy- Weinberg equilibrium
C. this can be understood as a classic case of genetic drift
D. obviously the African bee genes are dominant over the European honey bee alleles
E. gene flow is not occurring and therefore these are two separate species



If the Hardy-Weinberg equilibrium is met, what is the net effect?

A. very slow and continuous evolution with no increased adaptation
B. evolution leading to a population better adapted to an unchanging environment
C. no evolution because the alleles in the population remain the same
D. evolution leading to a population better adapted to a changing environment



What is the term used to describe the changes in allele frequencies of a population over generations?

A. founder effect
B. genetic drift
C. microevolution
D. directional selection