The Great Gatsby Test#1
3) Which of the following correctly describes the reproduction of males in Daphnia? A) Daphnia males are produced asexually from unfertilized eggs. B) Daphnia males are produced sexually through fertilization of eggs but are sterile from birth. C) Daphnia males are produced from a pseudosexual union of two eggs. D) Daphnia males are produced asexually but are sterile from birth.
A) Daphnia males are produced asexually from unfertilized eggs.
19) Why do histones bind tightly to DNA? A) Histones are positively charged, and DNA is negatively charged. B) Histones are negatively charged, and DNA is positively charged. C) Both histones and DNA are strongly hydrophobic. D) Histones are covalently linked to the DNA. E) Histones are highly hydrophobic, and DNA is hydrophilic.
A) Histones are positively charged, and DNA is negatively charged.
16) Which of the following correctly describes a difference between spermatogenesis and oogenesis? A) Spermatogenesis results in four mature sperm cells, whereas oogenesis results in one mature egg cell. B) Spermatogenesis results in one mature sperm cell, whereas oogenesis results in four mature egg cells. C) In spermatogenesis, mitosis occurs twice and meiosis once; in oogenesis, mitosis occurs once and meiosis twice. D) In spermatogenesis, mitosis occurs twice and meiosis once; in oogenesis, mitosis occurs once and meiosis twice.
A) Spermatogenesis results in four mature sperm cells, whereas oogenesis results in one mature egg cell.
30) The protein of the bicoid gene in Drosophila determines the of the embryo. A) anterior—posterior axis B) anterior—lateral axis C) posterior—dorsal axis D) posterior—ventral axis
A) anterior—posterior axis
32) During Drosophila development, there is a regulatory cascade of gene activation. The proper sequence for this cascade is . A) bicoid, gap genes, pair-rule genes, and segment-polarity genes B) bicoid, pair-rule genes, gap genes, and segment-polarity genes C) bicoid, segment-polarity genes, gap genes, and pair-rule genes D) bicoid, gap genes, segment-polarity genes, and pair-rule genes
A) bicoid, gap genes, pair-rule genes, and segment-polarity genes
13) Mature human sperm and ova are similar in that they . A) both have the same number of chromosomes B) are approximately the same size C) each have a flagellum that provides motility D) are produced from puberty until death E) are formed before birth
A) both have the same number of chromosomes
12) Muscle cells differ from nerve cells mainly because they A) express different genes B) contain different genes C) use different genetic codes D) have unique ribosomes E) have different chromosomes
A) express different genes
6) Muscle cells differ from nerve cells mainly because they . A) express different genes B) contain different genes C) use different genetic codes D) have unique ribosomes E) have different chromosomes
A) express different genes
1) Asexual reproduction results in offspring that are genetically identical to their parent. What type of cell process commonly occurs to generate this type of offspring? A) mitosis B) spermatogenesis C) cell fusion D) oogenesis
A) mitosis
15) Asexual reproduction results in offspring that are genetically identical to their parent. What type of cell process occurs to generate this type of offspring? A) mitosis B) meiosis C) cell fusion D) gametogenesis
A) mitosis
23) Histone acetyl transferases exert their effect on gene activity by . A) neutralizing positive charges on the lysines of histones B) introducing negative charges on the glutamic acids of histones C) modifying the DNA sequence of the promoter D) increasing the affinity of transcriptional activators for DNA E) increasing the affinity of transcriptional inhibitors for DNA
A) neutralizing positive charges on the lysines of histones
21) In eukaryotes, the normal or default state is that genes are turned . A) off through their association in nucleosomes B) off through their association with exons C) on through their association with exons D) on through their association in nucleosomes
A) off through their association in nucleosomes
28) The duplication of homeotic (Hox) genes has been significant in the evolution of animals because it . A) permitted the evolution of novel forms B) caused the extinction of major groups C) reduced morphological diversity into simpler forms of life D) allowed animals to survive on significantly fewer calories
A) permitted the evolution of novel forms
24) Internal and external fertilization both . A) produce single-celled zygotes B) occur only among invertebrates C) occur only among terrestrial animals D) depend on the use of copulatory organs E) occur only among birds
A) produce single-celled zygotes
19) What is the primary mechanism by which eukaryotes control transcription during cellular differentiation? A) regulatory transcription factors that influence chromatin structure and bind to regulatory regions B) production of microRNAs to disable mRNAs that should not be expressed C) post-translational control of proteins through ubiquitination and phosphorylation D) alternative splicing of genes in different tissue types E) inhibition of RNA polymerase through the expression of inhibitory enzymes
A) regulatory transcription factors that influence chromatin structure and bind to regulatory regions
38) Twenty-five years ago, when Oshima and colleagues discovered that a mutation in the GAL4 gene led to the inability to synthesize all five enzymes required for galactose catabolism (breakdown), they couldn't be blamed for wanting to apply a bacterial model to explain this finding. What they expected, but did not find, was . A) that all five genes constitute an operon B) five widely separated genes, each containing a GAL4-binding site in its regulatory region C) that chromatin decondensation played an important role in regulating the genes of galactose catabolism D) that transcription is important in regulating the genes of galactose catabolism
A) that all five genes constitute an operon
14) Cell differentiation always involves . A) the production of tissue-specific proteins, such as muscle actin B) the movement of cells C) the transcription of the myoD gene D) the selective loss of certain genes from the genome E) the cell's sensitivity to environmental cues, such as light or heat
A) the production of tissue-specific proteins, such as muscle actin
13) The functioning of enhancers is an example of A) transcriptional control of gene expression B) a post-transcriptional mechanism to regulate mRNA C) the stimulation of translation by initiation factors D) post-translational control that activates certain proteins E) a eukaryotic equivalent of prokaryotic promoter functioning
A) transcriptional control of gene expression
30) The functioning of enhancers is an example of . A) transcriptional control of gene expression B) a post-transcriptional mechanism to regulate mRNA C) the stimulation of translation by initiation factors D) post-translational control that activates certain proteins E) a eukaryotic equivalent of prokaryotic promoter functioning
A) transcriptional control of gene expression
20) Gene expression in developing organisms is regulated on several different levels. In many developing animals, regulation of gene expression is influenced by the action of Hox genes. Which of the following regulatory elements is produced by many Hox genes? A) transcriptional factors A) cell-surface molecules for cell—cell interactions B) signals from maternal cytoplasm, such as bicoid C) mRNA processing factors
A) transcriptional factors
7) The fibrous layer that surrounds an oocyte is called the . A) vitelline envelope B) jelly layer C) corona radiate D) plasma membrane E) acrosome
A) vitelline envelope
29) When the Bicoid protein is expressed in Drosophila, the embryo is still syncytial (divisions between cells are not yet fully developed). This information helps to explain which observation by Nüsslein-Volhard and Wieschaus? A) mRNA from the egg is translated into the Bicoid protein. B) Bicoid protein diffuses throughout the embryo in a concentration gradient. C) Bicoid protein serves as a transcription regulator. D) Bicoid protein determines the dorsoventral axis of the embryo.
B) Bicoid protein diffuses throughout the embryo in a concentration gradient.
18) Which of the following statements is TRUE of histones? A) Each nucleosome consists of two molecules of histone H1. B) Histone H1 is not present in the nucleosome bead; instead, it draws the nucleosomes together. C) The carboxyl end of each histone extends outward from the nucleosome and is called a "histone tail." D) Histones are found in mammals but not in other animals or in plants or fungi.
B) Histone H1 is not present in the nucleosome bead; instead, it draws the nucleosomes together
2) Which of the following is most TRUE of sexual reproduction? A) Sexual reproduction allows for more rapid population growth than does asexual reproduction. B) Only half of the offspring from sexually reproducing females are also females. C) Asexual reproduction produces offspring of greater genetic variety. D) Sexual reproduction is completed more rapidly than asexual reproduction. E) Asexual reproduction is better suited to environments with extremely varying conditions.
B) Only half of the offspring from sexually reproducing females are also females.
21) You decide to study two species of birds, both of which form monogamous pairs (one male and one female). In species 1, you find that the eggs in a pair's nest are in fact almost always the offspring of that pair. In species 2, you are surprised to find that many of the eggs in a nest were actually fathered by males of neighboring pairs. Apparently, mating outside of monogamous pairings is widespread in species 2. Given this information, what would be the logical prediction to make before comparing the testes size of males of the two species? A) Testes of species 1 are larger than testes of species 2. B) Testes of species 2 are larger than testes of species 1. C) The testes size of species 1 will increase throughout its lifespan, eventually becoming larger than that of species 2. D) There is no relationship between this observation and the size of testes.
B) Testes of species 2 are larger than testes of species 1.
17) If a cell were unable to produce histone proteins, which of the following would be a likely effect? A) There would be an increase in the amount of "satellite" DNA produced during centrifugation. B) The cell's DNA couldn't be packed into its nucleus. C) Spindle fibers would not form during prophase. D) Amplification of other genes would compensate for the lack of histones.
B) The cell's DNA couldn't be packed into its nucleus.
25) Suppose the protein specified by bicoid was injected into Drosophila embryos so that a high concentration was present everywhere in the embryo. What might be the result of such an experiment? A) The embryos would grow larger than normal. B) The embryos would show no development of posterior regions. C) The embryos would show no development of anterior regions. D) The embryos would halt their development.
B) The embryos would show no development of posterior regions.
26) Which of the following mechanisms is (are) used to coordinate the expression of multiple, related genes in eukaryotic cells? A) Environmental signals enter the cell and bind directly to promoters. B) The genes share a single common enhancer, which allows appropriate activators to turn on their transcription at the same time. C) The genes are organized into a large operon, allowing them to be coordinately controlled as a single unit. D) A single repressor is able to turn off several related genes.
B) The genes share a single common enhancer, which allows appropriate activators to turn on their transcription at the same time.
5) When we compare animal development to plant development, we find that . A) plant cells, but not animal cells, migrate during morphogenesis B) animal cells, but not plant cells, migrate during morphogenesis C) plant cells and animal cells migrate extensively during morphogenesis D) neither plant cells nor animal cells migrate during morphogenesis
B) animal cells, but not plant cells, migrate during morphogenesis
6) During metamorphosis, a tadpole's tail is reduced in size by the process of . A) regeneration B) apoptosis C) meiosis D) oxidative phosphorylation E) re-differentiation
B) apoptosis
27) In eukaryotes, general transcription factors . A) are required for the expression of specific protein-encoding genes B) bind to other proteins or to the TATA box C) inhibit RNA polymerase binding to the promoter and begin transcribing D) usually lead to a high level of transcription even without additional specific transcription factors E) bind to sequences just after the start site of transcription
B) bind to other proteins or to the TATA box
9) Sexual reproduction . A) allows animals to conserve resources and reproduce only during optimal conditions B) can produce diverse phenotypes that may enhance survival of a population in a changing environment C) yields more numerous offspring more rapidly than is possible with asexual reproduction D) enables males and females to remain isolated from each other while rapidly colonizing habitats E) guarantees that both parents will provide care for each offspring
B) can produce diverse phenotypes that may enhance survival of a population in a changing environment
10) You are interested in studying a receptor and decide to make a knockout mouse. However, you notice severe developmental defects that result in embryonic lethality in this receptor knockout. Which developmental process is most likely affected when you disrupt a receptor on the cell surface, disrupting its ability to receive a signal and initiate a transduction pathway? A) cell proliferation B) cell—cell interactions C) cell differentiation D) cell movement E) apoptosis
B) cell—cell interactions
21) Gap genes, segment-polarity genes, and homeotic genes all . A) act independently of one another B) code for transcription regulatory factors C) can be activated at any time during development D) are unique to Drosophila embryos
B) code for transcription regulatory factors
A researcher found a method she could use to manipulate and quantify phosphorylation and methylation in embryonic cells in culture. 14) In one set of experiments she succeeded in increasing acetlylation of histone tails. Which of the following results would she most likely see? A) increased chromatin condensation B) decreased chromatin condensation C) activation of histone tails for enzymatic function D) decreased binding of transcription factors E) inactivation of the selected genes
B) decreased chromatin condensation
31) In combination, the products of gap genes, pair-rule genes, and segmentation-polarity genes . A) trigger the reorganization of the larval body into an adult body B) define the segmented body plan of the embryo C) set up the back-to-belly axis of the larval body D) direct cell movements during differentiation
B) define the segmented body plan of the embryo
35) Regulatory transcription factors . A) influence the binding of sigma factor to DNA B) influence the assembly of the basal transcription complex C) influence the degree of unwinding of DNA at the promoter D) open the two strands of DNA so that RNA polymerase can begin transcription
B) influence the assembly of the basal transcription complex
34) An example of a basal transcription factor is . A) RNA polymerase B) the TATA-binding protein C) an enhancer-binding transcription factor D) a silencer-binding transcription factor E) a promoter-proximal-binding transcription factor
B) the TATA-binding protein
17) Within a cell, the amount of protein made using a given mRNA molecule depends partly on . A) the degree of DNA methylation B) the rate at which the mRNA is degraded C) the presence of certain transcription factors D) the number of introns present in the mRNA E) the types of ribosomes present in the cytoplasm
B) the rate at which the mRNA is degraded
5) In an animal that switches between sexual and asexual reproduction, when is sexual reproduction more likely to occur? A) when conditions for survival are favorable B) when conditions for survival are unfavorable C) when males and females find each other D) What conditions favor sexual over asexual reproduction remains a complete mystery.
B) when conditions for survival are unfavorable
Which of the following allows more than one type of protein to be produced from one gene? A) alternative forms of chromatin remodeling B) alternative forms of RNA splicing C) alternative forms of nucleosomes D) control of the frequency of translation initiation
B. Alternative forms of RNA splicing
22) Which statement about human reproduction is correct? A) Fertilization occurs in the uterus. B) In humans, spermatogenesis and oogenesis function best at normal, core body temperatures. C) A human oocyte completes meiosis after a sperm penetrates it. D) The earliest stages of spermatogenesis occur closest to the lumen of the seminiferous tubules.
C) A human oocyte completes meiosis after a sperm penetrates it.
26) Scientists have found that the lifetimes of mRNAs coding for pair-rule regulatory elements in Drosophila embryos may last only a few minutes. What does this suggest about the overall developmental plan of an animal body? A) The role of mRNAs is less important than the position of genes in chromosomes. B) Homeotic genes have greater impact in forming an embryo than mRNA from pair-rule genes. C) Building an animal body requires a sequence of precisely timed steps. D) Timing of pair-rule sequence determination is not as important as spatial signaling.
C) Building an animal body requires a sequence of precisely timed steps
11) Why is Caenorhabditis elegans an appropriate model organism for studying developmental processes? A) C. elegans does not undergo programmed cell death. B) C. elegans have meristems, regions that contain many stem cells. C) C. elegans is transparent and has only about 1000 cells, allowing the cells to be followed during development. D) C. elegans has millions of cells but can be easily mutated to have no gastrulation. E) C. elegans has genes that are completely unique from mice and humans.
C) C. elegans is transparent and has only about 1000 cells, allowing the cells to be followed during development.
32) If cells of an individual contain the same set of genes, how do these cells become different from each other during development? A) Different cell type-specific regulatory elements in DNA are created during development. B) Different cell type-specific regulatory elements in DNA are selectively lost during development. C) Differences in extracellular signals received by each cell lead to differences in the types of regulatory proteins present in each cell. D) Differences develop in promoter sequences that lead to different signals being produced by each type of cell.
C) Differences in extracellular signals received by each cell lead to differences in the types of regulatory proteins present in each cell.
24) Imagine that you have isolated a yeast mutant that contains a constitutively (constantly) active histone deacetylase. What phenotype do you predict for this mutant? A) The mutant will grow rapidly. B) The mutant will require galactose for growth. C) The mutant will show low levels of gene expression. D) The mutant will show high levels of gene expression.
C) The mutant will show low levels of gene expression
22) Imagine that you've isolated a yeast mutant that contains histones resistant to acetylation. What phenotype do you predict for this mutant? A) The mutant will grow rapidly. B) The mutant will require galactose for growth. C) The mutant will show low levels of gene expression. D) The mutant will show high levels of gene expression.
C) The mutant will show low levels of gene expression.
4) From earliest to latest, the overall sequence of early development proceeds in which of the following sequences? A) gastrulation → organogenesis → cleavage B) ovulation → gastrulation → fertilization C) cleavage → gastrulation → organogenesis D) gastrulation → blastulation → neurulation E) preformation → morphogenesis → neurulation
C) cleavage → gastrulation → organogenesis
27) Which of the following likely has the most Hox genes? A) jellyfish B) slugs C) dolphins D) bees
C) dolphins
36) Which of the following are maternal effect genes that control the orientation of the egg and thus the Drosophila embryo? A) homeotic genes B) segmentation genes C) egg-polarity genes D) morphogens E) inducers
C) egg-polarity genes
2) Meristematic tissue cells in plants are most similar to which kind of cells in animals? A) somite cells B) ectodermal cells C) embryonic stem cells D) mesodermal cells
C) embryonic stem cells
6) An advantage of asexual reproduction is that it . A) allows the species to endure long periods of unstable environmental conditions B) enhances genetic variability in the species C) enables the species to flourish in stable habitats that are favorable to that species D) produces offspring that respond effectively to new pathogens E) allows a species to easily rid itself of harmful mutations
C) enables the species to flourish in stable habitats that are favorable to that species
If you were to observe the activity of methylated DNA, you would expect it to A) be replicating nearly continuously B) be unwinding in preparation for protein synthesis C) have turned off or slowed down the process of transcription D) be very actively transcribed and translated E) induce protein synthesis by not allowing repressors to bind to it
C) have turned off or slowed down the process of transcription.
In a nucleosome, the DNA is wrapped around A) polymerase molecules B) ribosomes C) histones D) a thymine dimer E) satellite DNA
C) histones
19) For which of the following is the number the same in spermatogenesis and oogenesis? A) gametes produced over the lifetime of an organism B) functional gametes produced by meiosis C) meiotic divisions required to produce each gamete D) gametes produced in a given time period E) different cell types produced by meiosis
C) meiotic divisions required to produce each gamete
1) Which one of the following processes in a developing embryo is a prerequisite for all of the other processes? A) organogenesis B) cell differentiation C) mitosis D) germ layer formation
C) mitosis
10) All individuals of a particular species of whiptail lizards are females. Their reproductive efforts depend on . A) fertilization of their eggs by males of other lizard species B) gonadal structures that only undergo mitosis C) parthenogenesis D) budding prior to the development of a sexual phenotype E) fission of diploid gametes
C) parthenogenesis
11) For water fleas of the genus Daphnia, switching from a pattern of asexual reproduction to sexual reproduction coincides with . A) environmental conditions becoming more favorable for offspring B) greater abundance of food resources for offspring C) periods of temperature or food stresses on adults D) completion of puberty E) exhaustion of an individual's supply of eggs
C) periods of temperature or food stresses on adults
33) How do chromatin-remodeling complexes recognize the genes they should act on? Chromatin-remodeling complexes . A) are activated by specific extracellular signals that direct them to particular genes B) recognize specific promoters when they are phosphorylated, methylated, or acetylated C) recognize specific transcription factors bound to regulatory sequences of DNA D) bind to the basal transcription complex
C) recognize specific transcription factors bound to regulatory sequences of DNA
39) The reason for differences in the sets of proteins expressed in a nerve and a pancreatic cell of the same individual is that nerve and pancreatic cells contain different . A) genes B) regulatory sequences C) sets of regulatory proteins D) promoters E) promoter-proximal elements
C) sets of regulatory proteins
12) In vertebrate animals, spermatogenesis and oogenesis differ in that . A) oogenesis begins at the onset of sexual maturity, whereas spermatogenesis begins during embryonic development B) oogenesis produces four functional haploid cells, whereas spermatogenesis produces only one functional spermatozoon C) the division of cytoplasm is unequal in oogenesis, whereas it is equal in spermatogenesis D) oogenesis ends at menopause, whereas spermatogenesis is finished before birth E) spermatogenesis is not completed until after fertilization occurs, but oogenesis is completed by the time a girl is born
C) the division of cytoplasm is unequal in oogenesis, whereas it is equal in spermatogenesis
36) If the DNA sequence was substantially altered from one of the following, which would prevent the binding of the TATA-binding protein (TBP)? A) RNA polymerase B) the point where transcription begins C) the promoter D) promoter-proximal elements E) histone acetyl transferases (HATS)
C) the promoter
15) Which of the following is an example of post-transcriptional control of gene expression? A) the addition of methyl groups to cytosine bases of DNA B) the binding of transcription factors to a promoter C) the removal of introns and alternative splicing of exons D) gene amplification contributing to cancer E) the folding of DNA to form heterochromatin
C) the removal of introns and alternative splicing of exons
18) Which of the following characterizes parthenogenesis? A) An individual may change its sex during its lifetime. B) Specialized groups of cells grow into new individuals. C) An organism is first a male and then a female. D) An egg develops without being fertilized. E) Both mates have male and female reproductive organs.
D) An egg develops without being fertilized.
23) Suppose there was a mutation in the segment-polarity genes of Drosophila. What do you suppose might be the outcome? A) Several segments of the embryo will be missing. B) Every other segment of the embryo will be missing. C) Legs will appear in the place of antennae. D) Antennae will appear in a different part of their usual segment.
D) Antennae will appear in a different part of their usual segment.
37) The bicoid gene product is normally localized to the anterior end of the embryo. If large amounts of the product were injected into the posterior end as well, which of the following would occur? A) The embryo would grow to an unusually large size. B) The embryo would grow extra wings and legs. C) The embryo would probably show no anterior development and die. D) Anterior structures would form in both ends of the embryo. E) The embryo would develop normally.
D) Anterior structures would form in both ends of the embryo.
13) Two potential devices that eukaryotic cells use to regulate transcription are . A) DNA methylation and histone amplification B) DNA amplification and histone methylation C) DNA acetylation and methylation D) DNA methylation and histone modification E) histone amplification and DNA acetylation
D) DNA methylation and histone modification
18) Which of the following is TRUE of the cloning experiment that resulted in Dolly the sheep? A) Dolly was genetically identical to the egg-cell donor. B) Dolly was cloned by fusing an egg with an embryonic stem cell. C) Dolly was infertile, which indicated incomplete nuclear reprogramming. D) Dolly was cloned by using a differentiated cell fused to an egg from another breed of sheep. E) Dolly was cloned by fusing the nuclei from two separate eggs harvested from the same individual.
D) Dolly was cloned by using a differentiated cell fused to an egg from another breed of sheep.
4) Why was it informative for researchers to study the proximate causation of Daphnia switching reproductive tactics in the laboratory? A) Daphnia in the wild were genetically identical and the laboratory was the only place where Daphnia would reproduce sexually. B) Daphnia could not obtain enough energy in the wild to reproduce sexually. C) Daphnia were no longer available in the wild when the investigations occurred. D) The density of Daphnia populations could be easily manipulated in the laboratory.
D) The density of Daphnia populations could be easily manipulated in the laboratory.
24) Suppose the pair-rule genes were inactivated in Drosophila embryos. What is the likely result of the experiment? A) The embryos would develop normally. B) The embryos would lack several segments. C) The embryos would have impaired anterior—posterior polarity. D) The embryos would have missing alternate segments
D) The embryos would have missing alternate segments.
31) Imagine that you are studying the control of β-globin gene expression in immature red blood cells. (Mature red blood cells contain β-globin protein but lack a nucleus and, therefore, the β- globin gene.) If you deleted a sequence of DNA outside the protein-coding region of the β-globin gene and found that this increased the rate of transcription, the deleted sequence likely functions as . A) a promoter B) a promoter-proximal element C) an enhancer D) a silencer E) any of the listed functions
D) a silencer
16) Which of the following statements describes a eukaryotic chromosome? A) a single strand of DNA B) a series of nucleosomes wrapped around two DNA molecules C) a chromosome with different numbers of genes in different cell types of an organism D) a single linear molecule of double-stranded DNA plus proteins
D) a single linear molecule of double-stranded DNA plus proteins
37) The primary difference between enhancers and promoter-proximal elements is that enhancers. A) are transcription factors; promoter-proximal elements are DNA sequences B) enhance transcription; promoter-proximal elements inhibit transcription C) are part of the promoter; promoter-proximal elements are regulatory sequences distinct from the promoter D) are at considerable distances from the promoter; promoter-proximal elements are close to the promoter E) are DNA sequences; promoter-proximal elements are proteins
D) are at considerable distances from the promoter; promoter-proximal elements are close to the promoter
Which method is utilized by eukaryotes to control their gene expression that is NOT used in bacteria? A) control of chromatin remodeling B) control of RNA splicing C) transcriptional control D) control of both RNA splicing and chromatin remodeling E) control of chromatin remodeling, RNA splicing, and transcription
D) control of both RNA splicing and chromatin remodeling
25) The B-I mutation in anthocyanin (red pigments) produces pigmented corn plants, whereas the B′ mutation in the same gene usually produces nearly unpigmented corn plants when homozygous (B ́/B ́). When homozygous B-I and B′ plants are intercrossed, the F1 plants are essentially unpigmented, like the B′ homozygotes. If this outcome were due simply to the dominance of B′ to B-I, then a self-cross of the F1 plants (B ́/B-I) should generate B-I-colored homozygotes as approximately 1/4 (B-I/B-I) of the F2 progeny. Instead, no F2 are pigmented. Intercrosses of the F2 and of further generations do not restore the pigmented phenotype. What is the term for this type of inheritance? A) Mendelian inheritance B) organelle genome inheritance C) allelic inheritance D) epigenetic inheritance
D) epigenetic inheritance
12) DNA methylation and histone acetylation are examples of . A) genetic mutation B) chromosomal rearrangements C) karyotypes D) epigenetic phenomena E) translocation
D) epigenetic phenomena
14) Which of the following is an example of sexual reproduction? A) parthenogenesis in lizards B) budding in sponges C) binary fission in Amoeba D) fertilization in Daphnia
D) fertilization in Daphnia
9) Plant embryos do NOT undergo the process of . A) gene expression B) mitosis C) embryogenesis D) gastrulation
D) gastrulation
22) Suppose you found several Drosophila mutants that possessed additional legs growing out of their head segments. The probable mutation would be found in . A) segment-polarity genes B) gap genes C) pair-rule genes D) homeotic genes
D) homeotic genes
35) Mutations in which of the following genes lead to transformations in the identity of entire body parts? A) morphogens B) segmentation genes C) egg-polarity genes D) homeotic genes E) inducers
D) homeotic genes
A researcher found a method she could use to manipulate and quantify phosphorylation and methylation in embryonic cells in culture. 29) One of her colleagues suggested she try increased methylation of C nucleotides in the DNA of promoters of a mammalian system. Which of the following results would she most likely see? A) decreased chromatin condensation B) activation of histone tails for enzymatic function C) higher levels of transcription of certain genes D) inactivation of the selected genes
D) inactivation of the selected genes
At the beginning of this century there was a general announcement regarding the sequencing of the human genome and the genomes of many other multicellular eukaryotes. Many people were surprised that the number of protein-coding sequences was much smaller than they had expected. Which of the following could account for much of the DNA that is NOT coding for proteins? A) most of the DNA serving as origins of DNA replication B) DNA that consists of histone coding sequences C) DNA that is translated directly without being transcribed D) non-protein-coding DNA that is transcribed into several kinds of small RNAs with biological function E) non-protein-coding DNA that serves as binding sites for reverse transcriptase
D) non-protein-coding DNA that is transcribed into several kinds of small RNAs with biological function
28) Activator proteins in eukaryotes usually have a domain that binds to DNA and other activation domains that often bind to . A) DNA polymerases B) ATP C) protein-based hormones D) other regulatory proteins E) tRNA
D) other regulatory proteins
20) On a submarine expedition to the ocean bottom, you discover a population of fish that are only female. What type of reproduction does this fish most likely use? A) sexual B) budding C) cloning D) parthenogenesis
D) parthenogenesis
8) Gastrulation is an important event in early embryonic development. Which of the following is NOT a result of gastrulation? A) formation of three embryonic cell layers B) movement and alignment of many embryonic cells C) the formation of a gastrula D) the formation of specialized adult tissues
D) the formation of specialized adult tissues
7) During gastrulation, . A) the neural tube forms B) the blastula forms C) somites form D) three germ layers form
D) three germ layers form
17) During oogenesis, meiosis results in . A) four equally sized cells that stop dividing in meiosis I B) two equally sized cells that are both typically fertilized C) two equally sized cells, but only one that is typically fertilized D) two or three small cells and one large cell that develops further if fertilized
D) two or three small cells and one large cell that develops further if fertilized
20) Which of the following is most critical for the association between histones and DNA? A) Histones are small proteins. B) Histones are highly conserved (that is, histones are very similar in every eukaryote). C) Histones are synthesized in the cytoplasm. D) There are at least five different histone proteins in every eukaryote. E) Histones are positively charged.
E) Histones are positively charged.
16) Which of the following statements about the DNA in one of your brain cells is TRUE? A) Most of the DNA codes for protein. B) All of the genes of the genome are likely to be transcribed. C) Each gene lies immediately adjacent to an enhancer. D) Many genes are grouped into operon-like clusters. E) It is the same as the DNA in one of your heart cells.
E) It is the same as the DNA in one of your heart cells.
38) Suppose you have identified a type of lizard that seems to have acquired a mutation in which hindlimbs are absent. Which gene, also responsible for the loss of limbs in snakes, may be mutated in this animal? A) bicoid B) MONOPTEROS C) PHANTASTICA D) cytoplasmic determinants E) Sonic hedgehog
E) Sonic hedgehog
8) Asexual reproduction results in greater reproductive success than does sexual reproduction when . A) pathogens are rapidly diversifying B) a species has accumulated numerous deleterious mutations C) there is some potential for rapid overpopulation D) a species is expanding into diverse geographic settings E) a species is in stable and favorable environments
E) a species is in stable and favorable environments
Several of the different globin genes are expressed in humans but at different times in development. What mechanism could allow for this? A) exon shuffling B) intron activation C) pseudogene activation D) differential translation of mRNAs E) differential gene regulation over time
E) differential gene regulation over time
33) Your brother has just purchased a new plastic model airplane. He places all the parts on the table in approximately the positions in which they will be located when the model is complete. His actions are analogous to which process in development? A) morphogenesis B) determination C) induction D) differentiation E) pattern formation
E) pattern formation
34) The product of the bicoid gene in Drosophila provides essential information about . A) lethal genes B) the dorsal—ventral axis C) the left—right axis D) segmentation E) the anterior—posterior axis
E) the anterior—posterior axis
Which of the following statements about DNA in one of your brain cells is TRUE? A) Most of the DNA codes for protein. B) All of the genes of the genome are likely to be transcribed. C) Each gene lies immediately adjacent to an enhancer. D) Many related genes are transcribed from a single promoter. E) It is the same as the DNA in one of your heart cells.
It is the same as the DNA in one of your heart cells.
Mammals have a family between 500 and 1000 genes that encode receptor proteins on the surface of odor-receptor neurons. If all mammals have these genes, why do some mammals have a better sense of smell than others do? A) Some of the genes actively transcribing receptor proteins in some species are completely absent in other species. B) Some of the genes may have been mutated and rendered inactive in some species but not in others. C) Some species, particularly humans, rely much less on odor detection for survival; thus, the genes have mutated to encode proteins that aid in other senses, such as sight. D) Some species of mammals have a larger set of "basic odors" than other species.
Some of the genes may have been mutated and rendered inactive in some species but not in others.
The Predominant mechanism driving cellular differentiation is the difference in gene_________. A) expression B) sequences C) order D) replication
expression
3) Cells move to new positions as an embryo establishes its three germ-tissue layers during . A) determination B) cleavage C) fertilization D) induction E) gastrulation
gastrulation
Cloning of plants from cutting demonstrates that __________. A) an individual plant cell cannot de-differentiate and then re-differentiate B) differentiated plant cells may contain embryonic mRNAs C) plants lose genetic information in the differentiation process D) mature plant cells retain the full genetic information needed to carry out the developmental processes to produce a new individual plant
mature plant cells retain the full genetic information needed to carry out the developmental processes to produce a new individual plant
Cell differentiation always involves . A) the production of tissue-specific proteins, such as muscle actin B) the movement of cells C) the transcription of the myoD gene D) the selective loss of certain genes from the genome E) the cell's sensitivity to environmental cues, such as light or heat
the production of tissue-specific proteins, such as muscle actin.