Spring Biology Final Exam Review Chapter 14 Mendel and the Gene Idea

1) What do we mean when we use the terms monohybrid cross and dihybrid cross?

A dihybrid cross involves organisms that are heterozygous for two characters and

a monohybrid cross involves only one.

2) Two plants are crossed, resulting in offspring with a 3:1 ratio for a particular trait. What

does this suggest?

that the parents were both heterozygous for a single trait

3) When crossing an organism that is homozygous recessive for a single trait with a

heterozygote, what is the chance of producing an offspring with the homozygous

recessive phenotype?

50%

4) In certain plants, tall is dominant to short. If a heterozygous plant is crossed with a

homozygous tall plant, what is the probability that the offspring will be short?

0

Chapter 15 The Chromosomal Basis of Inheritance

5) When Thomas Hunt Morgan crossed his red-eyed F1 generation flies to each other, the

F2 generation included both red- and white-eyed flies. Remarkably, all the white-eyed

flies were male. What was the explanation for this result?

The gene involved is on the X chromosome.

6) Males are more often affected by sex-linked traits than females because

males are hemizygous for the X chromosome.

7) SRY is best described in which of the following ways?

a gene region present on the Y chromosome that triggers male development

8) In humans, clear gender differentiation occurs, not at fertilization, but after the second

month of gestation. What is the first event of this differentiation?

activation of SRY in male embryos and masculinization of the gonads

9) What is the reason that linked genes are inherited together?

They are located close together on the same chromosome.

10) What is the source of the extra chromosome 21 in an individual with Down syndrome?

nondisjunction or translocation in either parent

Chapter 16 The Molecular Basis of Inheritance

11) Describe transformation in bacteria?

A) assimilation of external DNA into a cell

12) In an analysis of the nucleotide composition of DNA, how should the percentages of

Cytosine, Guanine, Adenine and Thymine relate to each other?

A) A + C = G + T

13) The DNA of telomeres has been found to be highly conserved throughout the evolution

of eukaryotes. What does this most probably reflect?

that the critical function of telomeres must be maintained

14) How do the leading and the lagging strands of DNA differ?

the leading strand is synthesized in the same direction as the movement of the

replication fork, and the lagging strand is synthesized in the opposite direction.

15) If a cell were unable to produce histone proteins, which of the following would be a

likely effect during cell reproduction?

The cell's DNA couldn't be packed into its nucleus.

16) Why do histones bind tightly to DNA?

Histones are positively charged, and DNA is negatively charged.

17) The genetic code is essentially the same for all organisms. What can one logically assume

from this in relation to transformation?

A) A gene from an organism can theoretically be expressed by any other organism.

18) What characteristic of DNA provides some evidence that RNA probably evolved before

DNA?

A) DNA polymerase uses primer, usually made of RNA.

19) What molecules of post-transcription are attached to mRNA for eukaryotic gene

expression, but are not attached to the mRNA of prokatyotes?

A poly-A tail is added to the 3' end of an mRNA and a cap is added to the 5' end.

20) A part of the promoter, called the TATA box, is said to be highly conserved in

evolution. What does this illustrate?

A) Any mutation in the sequence is selected against.

21) What does Alternative RNA splicing permit?

can allow the production of proteins of different sizes from a single mRNA.

22) A particular triplet of bases in the coding sequence of DNA is AAA. The anticodon on

the tRNA that binds the mRNA codon is:

UUU.

23) Why might a point mutation in DNA make a difference in the level of protein's activity?

It might substitute an amino acid in the active site.

24) What kind of mutation(s) can result in a frameshift mutation?

either an insertion or a deletion of a base.

25) What kind of DNA mutation(s) is most likely to be damaging to the protein it specifies?

a base-pair deletion

26) How does protein synthesis differ in prokaryotes and eukaryotes?

Translation can begin while transcription is still in progress.

27) What is the most current description of a gene?

a DNA sequence that is expressed to form a functional product: either RNA or

polypeptide

28) In eukaryotic cells, what molecules are needed for transcription of DNA to begin?

several transcription factors have bound to the promoter.

29) What molecules, when taken up by the cell, binds to the repressor so that the repressor no

longer binds to the operator?

inducer

30) Most repressor proteins are allosteric. What molecule binds with the repressor to alter its

conformation?

inducer

31) What would result from a mutation that inactivates the regulatory gene of a repressible

operon in an E. coli cell?

continuous transcription of the structural gene controlled by that regulator.

32) What must occur for a repressible operon to be transcribed?

RNA polymerase must bind to the promoter, and the repressor must be inactive.

33) What are two potential devices that eukaryotic cells use to regulate transcription?

DNA methylation and histone modification.

Chapter 22 Descent with Modification: A Darwinian View of Life

34) What best describes theories versus hypotheses?

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

35) Charles Darwin was the first person to propose

a mechanism for evolution that was supported by evidence.

36) What was the major idea that Darwin learned from the writings of Thomas Malthus?

37) Which of the following must exist in a population before natural selection can act upon

that population?

genetic variation among individuals

38) What role do humans play in artificial selection?

choose which organisms breed, and which do not.

39) What is homologous to the bones in the wing of a bird?

bones in the flipper of a whale

40) 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

island forms and mainland forms descended from common ancestors.

Chapter 23 The Evolution of Populations

41) In modern terminology, diversity is understood to be a result of genetic variation. What

are recognized sources of variation for evolution?

recombination by crossing over in meiosis

42) How does Hardy-Weinberg relate to evolution?

can happen whenever any of the conditions for Hardy-Weinberg equilibrium are

not met.

43) How do mutations and natural selection relate to generating evolution?

Mutations occur at random; natural selection can preserve and distribute

beneficial mutations.

44) What is the best summary of evolution as it is viewed today?

It is the differential survival and reproduction of the most-fit phenotypes.

45) Most Swiss starlings produce four to five eggs in each clutch. Starlings producing fewer,

or more, than this have reduced fitness. What term best describes this type of selection?

stabilizing selection

46) What type of selection is heterozygote advantage most closely linked?

stabilizing selection

Chapter 24 The Origin of Species

47) Two species of frogs belonging to the same genus occasionally mate, but the offspring

fail to develop and hatch. What is the mechanism for keeping the two frog species

separate?

the postzygotic barrier called hybrid inviability

48) The origin of a new plant species by hybridization, coupled with accidents during nuclear

division, is an example of what kind of speciation?

sympatric speciation.

49) How is a hybrid zone properly defined?

an area where mating occurs between members of two closely related species,

producing viable offspring.

50) What phenomenon should decline in hybrid zones where reinforcement is occurring?

gene flow between distinct gene pools

51) According to the concept of punctuated equilibrium, the "sudden" appearance of a new

species in the fossil record means that

speciation occurred rapidly in geologic time.

52) According to the concept of punctuated equilibrium, when does a new species acquire

most of its unique features?

a new species accumulates most of its unique features as it comes into existence.

53) Males of different species of the fruit fly Drosophila that live in the same parts of the

Hawaiian Islands have different elaborate courtship rituals. These rituals involve fighting

other males and making stylized movements that attract females. What type of

reproductive isolation does this represent?

behavioral isolation

Chapter 26 Phylogeny and the Tree of Life

54) What is the single most important characteristic of a good classification system?

It reflects evolutionary history.

55) What are some good examples of homologous structures?

bones in the bat wing and bones in the human forelimb

56) Be able to discern relatedness for a a phylogenetic tree constructed using sequence

differences in mitochondrial DNA.

chimpanzees and humans.

57) What are examples of shared, ancestral characteristics?

a shared ancestral character – bird wing, human arm.

58) To apply parsimony to constructing a phylogenetic tree, what must one choose?

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

sequences or morphology.

59) If you were using cladistics to build a phylogenetic tree of cats, what kind of organism

could be used to represent the outgroup?

Chapter 38 Angiosperm Reproduction and Biotechnology

60) Name several primary functions of flowers.

a. pollen production.

b. meiosis.

c. egg production.

61) In what flower parts can meiosis be described as occurring?

a. megasporangium.

b. anther.

c. ovule

62) In flowering plants, pollen is released from the

anther.

63) What is the male gametophyte of a flowering plant?

pollen grain

64) What is the difference between pollination and fertilization in flowering plants?

Pollination is the transfer of pollen from an anther to a stigma. Fertilization is the

fusion of haploid nuclei.

65) The structure of a mature, functional fruit always includes

one or more seeds.

66) What do fruits develop from?

ovaries.

67) What is an advantage of sexual reproduction as opposed to asexual reproduction?

a. increased genetic variation in progeny

68) What is a fruit?

a. a mature ovary.

69) What does double fertilization mean?

a. one sperm is needed to fertilize the egg, and a second sperm is needed to fertilize

the polar nuclei.

Chapter 39 Plant Responses to Internal and External Signals

70) Plants growing in a partially dark environment will grow toward light in a response called

phototropism. How does auxin produce this result?

Auxin causes a growth increase on one side of the stem.

71) We know from the experiments of the past that plants bend toward light because

a. cell expansion is greater on the dark side of the stem.

72) The ripening of fruit and the dropping of leaves and fruit are principally controlled by the

hormone _______________

ethylene.

73) The plant hormone involved in aging and ripening of fruit is

a. ethylene.

74) How do plant hormones produce their effects?

altering the expression of genes and modifying the permeability of the plasma

membrane.

75) Which of the following statements best summarizes the acid growth hypothesis in an

actively growing shoot?

Auxin-activated proton pumps lower the pH of the cell wall, which breaks bonds

and makes the walls more flexible

76) If you were shipping green bananas to a supermarket thousands of miles away, which of

the following chemicals would you want to eliminate from the plants' environment?

ethylene

77) We tend to think of plants as immobile when, in fact, they can move in many ways. What

are legitimate ways in which plants move?

growth movements toward or away from light

78) A short-day plant will flower only when

nights are longer than a certain critical value.

79) Many plants flower in response to day-length cues. What cell type is responsible to

monitoring day length?

Flowering in short-day and long-day plants is controlled by phytochrome.

80) What must a biological clock controlling circadian rhythms ultimately do?

affect gene transcription.

81) Plants often use changes in day length (photoperiod) to trigger events such as dormancy

and flowering. Why is it logical that plants have evolved this mechanism over

temperature changes?

are more predictable than air temperature changes.

Chapter 40 Basic Principles of Animal Form and Function

82) Which is a reasonable mechanism for animal structures becoming better suited over

evolutionary time to specific functions?

Animals with mutations that give rise to effective structures will become more

abundant.

83) What process produced penguins, seals, and tuna with body forms that permit rapid

swimming, but not because of descent from a common ancestor?

the shape is a convergent evolutionary solution to the need to reduce drag while

swimming.

84) What happens to an animal’s surface area-to-volume ratio as body size increases?

a. there is a decrease in the surface-to-volume ratio.

85) To increase the effectiveness of exchange surfaces lining the lungs and the intestines,

evolutionary pressures have

a. increased the exchange surface area with folds and branches.

86) Describe positive feedback and give at least one example.

uterine contractions needed for the birthing process are expedited by the pressure

of a moving baby in its mother's uterus.

87) In a survivably cold environment, an ectotherm is more likely to survive an extended

period of food deprivation than would an equally sized endotherm because the ectotherm

invests little energy in temperature regulation.

88) Panting by an overheated dog achieves cooling by

evaporation.

89) What does the thin horizontal arrows in the figure above show?

the warmer arterial blood transfers heat to the cooler venous blood.

90) Examine the figure above. Near a goose's abdomen, what does the countercurrent

arrangement of the arterial and venous blood vessels cause?

a. the temperature difference between the contents of the two sets of vessels to be

minimized.

Chapter 43 The Immune System 91) What are typical inflammatory response symptoms?

i. increased activity of phagocytes in an inflamed area.

92) Histamines trigger dilation of nearby blood vessels as well as an increase in their

permeability, producing

redness, heat, and swelling.

93) What do the receptors on T cells and B cells bind to

A) antigens.

94) What is the function of antibodies?

A) mark pathogenic cells for destruction.

Chapter 52 Intro to Ecology

95) What type of investigation would shed the most light on the distribution of organisms in

temperate regions that are faced with climate change?

Look back at the changes that occurred since the Ice Age and how species

redistributed as glaciers melted, then make predictions on future distribution in

species based on past trends.

96) What is the correct sequence of layers from top to bottom in a tropical rain forest?

emergent layer, canopy, under story, shrub/immature layer, ground layer

Chapter 53 Population Ecology

97) An ecologist recorded 12 white-tailed deer, Odocoileus virginianus, per square mile in

one woodlot and 20 per square mile in another woodlot. What was the ecologist

comparing?

Density

98) Long-term studies of Belding's ground squirrels show that immigrants move nearly 2 km

from where they are born and become 1%-8% of the males and 0.7%-6% of the females

in other populations. On an evolutionary scale, why is this significant?

A) These immigrants provide a source of genetic diversity for the other populations.

99) What population measuring techniques would provide the most legitimate data on

population density?

Count the number of pine trees in several randomly selected 10 m x 10 m plots

and extrapolate this number to the fraction of the study area these plots represent.

100) Consider two forests: one is an undisturbed old-growth forest, while the other has

recently been logged. In which forest are species likely to experience exponential growth,

and why?

Logged, because the disturbed forest affords more resources for increased specific

populations to grow.

100. What is carrying capacity?

the maximum population size that a particular environment can support.

101. What factor most often causes populations to shift most quickly from an exponential to a

logistic population growth?

competition for resources

102.Natural selection involves energetic trade-offs between what two factors?

high survival rates of offspring and the cost of parental care.

103.Why do populations grow more slowly as they approach their carrying capacity?

Density-dependent factors lead to fewer births and increased mortality.

Please read the paragraph below and review Figure 53.2 to answer the following

question.

Researchers in the Netherlands studied the effects of parental care given in

European kestrels over five years. The researchers transferred chicks among nests

to produce reduced broods (three or four chicks), normal broods (five or six chicks),

and enlarged broods (seven or eight chicks). They then measured the percentage of

male and female parent birds that survived the following winter. (Both males and

females provide care for chicks.)

Figure 53.2: Brood size manipulations in the kestrel: Effects on offspring and parent

survival.

104.What can one conclusion can be drawn from this graph regarding parental survival

through the winter after brooding?

There appears to be a negative correlation between brood enlargements and

parental survival.

Refer to Figure 53.4 and then answer the following questions.

Figure 53.4: Infant mortality and life expectancy at birth in developed and

developing countries (data as of 2005).

105.Why do population ecologists follow the fate of same-age cohorts?

To determine the birth rate and death rate of each group in a population.

Chapter 54 Community Ecology

106.What is the principle of competitive exclusion?

Even a slight reproductive advantage will eventually lead to the elimination of the

less well adapted of two competing species.

107.As you study two closely related predatory insect species, the two-spot and the three-spot

avenger beetles, you notice that each species seeks prey at dawn in areas without the other

species. However, where their ranges overlap, the two-spot avenger beetle hunts at night

and the three-spot hunts in the morning. When you bring them into the laboratory and

isolate the two different species, you discover that the offspring of both species are found

to be nocturnal. You have discovered an example of

resource partitioning.

108.What are examples of Batesian mimicry?

a nonvenomous snake that looks like a venomous snake

109.Elephants are not the most dominant species in African grasslands, yet they influence

community structure. The grasslands contain scattered woody plants, but they are kept in

check by the uprooting activities of the elephants. Take away the elephants, and the

grasslands convert to forests or to shrublands. The newly growing forests support fewer

species than the previous grasslands. Why are elephants the keystone species in this

scenario?

A) Essentially all of the other species depend on the presence of the elephants to

maintain the community.

110.Which of the following is the most accepted hypothesis as to why invasive species take

over communities into which they have been introduced?

Invasive species are not held in check by the predators and agents of disease that

have always been in place for the native species.

111. The 1988 Yellowstone National Park lodgepole pine forest fires were likely the result of

years of fire suppression by humans.

112.Why do moderate levels of disturbance result in an increase in community diversity?

Habitats are opened up for less competitive species.

Chapter 55 Ecosystems and Restoration Ecology

113.Many homeowners mow their lawns during the summer and collect the clippings, which

are then hauled to the local landfill. What actions would most benefit the suburban

ecosystem?

Collect the lawn clippings and add them to a compost pile, don't collect the

clippings and let them decompose into the lawn, or apply composted clippings to

the lawn.

114.How does inefficient transfer of energy among trophic levels result in the typically high

endangerment status of many top-level predators?

Top-level predators are destined to have small populations that are sparsely

distributed.

115.For most terrestrial ecosystems, pyramids of numbers, biomass, and energy are essentially

the same. They have a broad base and a narrow top. What is the primary reason for this

pattern?

at each step, energy is lost from the system as a result of keeping the organisms

alive.

116.Which of the following is primarily responsible for limiting the number of trophic levels

in most ecosystems?

Energy transfer between tropic levels is in almost all cases less than 20%

efficient.

117.Which trophic level is most vulnerable to extinction?

tertiary consumer level

118.Secondary consumers that can eat only primary consumers receive what percent of the

energy fixed by primary producers in a typical field ecosystem?

1%

119.In terms of nutrient cycling, why does timber harvesting in a temperate forest cause less

ecological devastation than timber harvesting in tropical rain forests?

Typical harvests remove up to 75% of the nutrients in the woody trunks of

tropical rain forest trees, leaving nutrient-impoverished soils behind.

Chapter 56 Conservation Biology and Global Change

120.What is a critical load?

the amount of added nutrient that can be absorbed by plants without damaging

ecosystem integrity

2013 FRQ

Directions: Answer all questions.

Answers must be in essay form. Outline form is not acceptable. Labeled diagrams may be used to

supplement discussion, but in no case will a diagram alone suffice. It is important that you read each

question completely before you begin to write. Write all your answers on the pages following the

questions in the pink booklet.

A laboratory assistant prepared solutions of 0.8 M, 0.6 M, 0.4 M, and 0.2 M sucrose, but forgot to label

them. After realizing the error, the assistant randomly labeled the flasks containing these four unknown

solutions as flask A, flask B, flask C, and flask D.

Design an experiment, based on the principles of diffusion and osmosis, that the assistant could use to

determine which of the flasks contains each of the four unknown solutions.

Include in your answer (a) a description of how you would set up and perform the experiment; (b) the

results you would expect from your experiment; and (c) an explanation of those results based on the

principles involved. (Be sure to clearly state the principles addressed in your discussion.)