Final Exam Cumulative Questions

As cleavage continues during frog development, the number of cells in a blastula _____. A) increases as the size of the cells decreases. B) increases as the size of the cells stays the same. C) increases as the size of the cells increases. D) decreases as the size of the cells increases. E) decreases as the size of the cells decreases.

A

Which of the following process and stabilize mRNA by inhibiting its degradation? a. TATA box b. spliceosomes c. 5' cap d. poly-A tail e. C and D

5' cap and poly-A tail

If an amphibian zygote is manipulated so that the first cleavage plane does not divide the gray crescent, what is the expected fate of the two daughter cells? A) Only the daughter cell with the gray crescent will develop normally. B) Both daughter cells will develop normally because amphibians are totipotent at this stage. C) The daughter cell with the entire gray crescent will die. D) Both daughter cells will develop abnormally. E) Both daughter cells will die immediately.

A

In animals, embryonic stem cells differ from adult stem cells in that ______. A) embryonic stem cells can be totipotent, and adult stem cells are multipotent. B) embryonic stem cells have fewer genes than adult stem cells. C) embryonic stem cells are differentiated whereas adult stem cells are not. D) embryonic stem cells have more genes than adult stem cells. E) embryonic stem cells can be totipotent, and adult stem cells are pluripotent.

A

Once transcribed, eukaryotic mRNA typically undergoes substantial alteration that includes ______. A) excision of introns. B) fusion with other newly transcribed mRNA. C) fusion into circular forms known as plasmids. D) union with ribosomes. E) linkage to histone molecules.

A

Which of the following is true concerning a bone marrow cell and a nerve cell? A) They are genomically equivalent. B) Both are pluripotent but totipotency can be induced given the correct cell-culture conditions. C) Both are totipotent but pluripotency can be induced given the correct cell-culture conditions. D) Both are examples of undifferentiated adult stem cells. E) none of the above

A. they are genomically equivalent

If gastrulation within an embryo was blocked by an environmental toxin, then ___. A) cleavage would not occur in the zygote B) embryonic germ layers would not form C) fertilization would be blocked D) a blastula would not form E) yolk would not be produced

B) embryonic germ layers would not form

Initial contact of sperm and egg signal molecules causes the egg to undergo _____. A) cell division B) membrane depolarization C) an expansion in size D) a permanent block to polyspermy E) the acrosomal reaction

B) membrane depolarization

The "information content" of DNA is contained in _____. A) the molecule's sugar-phosphate backbone B) the molecule's sequence of nitrogenous bases C) the molecule's different 5-carbon sugars D) the width of the molecule's double helix E) the molecule's anticodons

B) the molecule's sequence of nitrogenous bases

A cell that remains entirely flexible in its developmental possibilities is said to be ______. A) epigenetic. B) under post-transcriptional regulation. C) determined. D) totipotent. E) differentiated.

D

Muscle cells and nerve cells in one species of animal owe their differences in strucutre to ______.

DiIfferential gene expression

Hans Spemann has referred to which of the following structures as the primary "organizer" in the early development of amphibian embryos? A) notochord B) neural tube C) optic cup D) dorsal ectoderm E) dorsal lip of the blastopore

E

What is the outer-to-inner sequence of germ layers in a vertebrate embryo? A) endoderm, ectoderm, mesoderm. B) endoderm, mesoderm, ectoderm. C) ectoderm, endoderm, mesoderm. D) mesoderm, endoderm, ectoderm. E) ectoderm, mesoderm, endoderm.

E

Which one of the following plays a major role in gas exchange in a chick embryo? A) trophoblast B) hypoblast C) amnion D) yolk sac E) chorion

E

Why was the cloning of "Dolly" considered a major scientific breakthrough? A) It was the first time an organism had been cloned. B) It proved that the pattern of gene expression is controlled at transcription. C) It showed that cells can be arrested in the cell cycle. D) It was evidence that DNA methylation regulates gene expression. E) It showed that genes in differentiated adult cells of mammals can

E

Without the formulation of an ectoderm, vertebrates would not form _______. A) pancreas. B) a liver. C) kidneys. D) heart. E) a nervous system.

E

An inward movement of outer cells during _____ gives rise to an embryonic primitive gut, or ____. A) cleavage; blastocoel B) cleavage; archenteron C) blastulation; blastocoel D) gastrulation; blastocoel E) gastrulation; archenteron

E) gastrulation; archenteron

Initial contact of sperm and egg signal molecules causes the sperm to undergo _____. A) cell division B) membrane depolarization C) an expansion in size D) a permanent block to polyspermy E) the acrosomal reaction

E) the acrosomal reaction

Using RNA as a template for protein synthesis instead of translating proteins directly from the DNA is advantageous for the cell because___________.

RNA acts as an expendable copy of the genetic material, allowing the DNA to serve as a permanent, pristine repository of the genetic materal. Many mRNA molecules can be transcribed from a single gene, increaasing the potential rate of gene expression.

RNA polymerase binds to DNA at a region called a(n) __________. A) operator B) inducer C) promoter D) repressor E) co-repressor

promoter

For a molecular signal to evoke a specific cellular response, it must frist interact with a __________.

receptor

From the perspective of the cell receiving the message, the three stages of cell signaling are ____. A) signal reception, signal transduction, and cellular response B) signal reception, nucleus disintegration, and new cell generation C) replication, transcription, and translation D) signal transduction, cellular response, and cell division E) the paracrine, local, and synaptic stages

signal reception, signal transduction, and cellular response

What is an anticodon part of? A) tRNA B) mRNA C) DNA D) a ribosome E) RNA polymerase

tRNA

What molecule is an anticodon part of? a. DNA b. tRNA c. mRNA d. rRNA e. an operon

tRNA

Which is true of transcription factors? (read choices carefully!) A) They are control elements needed to regulate the synthesis of protein in the cytoplasm. B) They transcribe ATP into cAMP. C) They control which genes are turned on to form mRNA. D) They regulate the synthesis of DNA in response to a signal. E) They are control elements that regulate post-transcriptional processing in animal cells.

they control which genes are turned on to form mRNA

All of the following are made up of nucleic aid except a ___________.

transcription fact- it's a protein.

In eukaryotes, transcription can occur for ________.

both euchromatin and histone acetylation

Which of the following accurately distinguishes a pluripotent human cell from a totipotent cell? a. the pluripotent cell has half the number of chromosomes as the totipotent cell b. the totipotent cell has more genes c. genes are regulated in the pluripotent cell but not in the totipotent cell d. determination has progressed further in the pluripotent cell.

d. determination has progressed further in the pluripotent cell.

The combined length of the introns in a gene is 3000 nucleotides. The combined length of the same gene's exons is 660 nucleotides. Which of the following is the best estimate for the number of amino acids in the protein encoded by this gene?

220

Changes in the shape of a cell usually involve a reorganization of ______. A) cytoskeletal microtubules. B) the nucleus. C) transport proteins. D) the extracellular matrix. E) none of the above.

A

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) Anterior structures would form in both sides of the embryo. B) The embryo would grow to an unusually large size. C) The embryo would grow extra wings and legs. D) The embryo would develop normally. E) The embryo would probably show no anterior development and die.

A

The term applied to a morphogenetic process whereby groups of cells extend themselves, making the mass of cells narrower and longer, is ______. A) convergent extension. B) ingression. C) bi-axial elongation. D) filopodial extension. E) induction.

A

What is the process called that involves the movement of cells into new relative positions in an embryo and results in the establishment of three germ tissue layers? A) gastrulation B) determination C) neurulation D) induction E) cleavage

A

Which of the following is not true of cell communication systems? A) Most signal receptors are bound to the outer membrane enclosing the nucleus. B) Signaling mechanisms occur in eukaryotic cells, but not in prokaryotic cells. C) Communicating cells may be far apart or close together. D) Phosphorylation cascades are a major mechanism of signal transduction. E) In response to a signal, the cell may alter activities by changes in transcription of RNA.

A

Which statement about cell adhesion molecules (CAMs) is false? A) They are all produced by the same gene. B) They contribute to cell's being able to migrate. C) They bind to CAMs on other cells. D) They contribute to stable tissue structure. E) They are glycoproteins.

A

What is a hypothesis?

A tentative explanation that can be tested and is falsifiable.

Which of the following best represents the flow of information in eukaryotic cells? A) DNA → RNA → proteins B) RNA → proteins → DNA C) proteins → DNA → RNA D) RNA → DNA → proteins E) DNA → proteins → RNA

A) DNA → RNA → proteins

In animals, embryonic stem cells differ from adult stem cells in that _____. A) embryonic stem cells are totipotent, and adult stem cells are pluripotent B) embryonic stem cells are pluripotent, and adult stem cells are totipotent C) embryonic stem cells have more genes than adult stem cells D) embryonic stem cells have fewer genes than adult stem cells E) embryonic stem cells are more differentiated than adult stem cells

A) embryonic stem cells are totipotent, and adult stem cells are pluripotent

Which of the following is true regarding deoxyribonucleic acid (DNA)? A) Genes are composed of deoxyribonucleic acid. B) Each deoxyribonucleic acid molecule is composed of two long chains of nucleotides arranged in a double helix. C) DNA is composed of chemical building blocks called nucleotides. D) Only A and C are correct. E) A, B, and C are correct.

A, B, and C are correct

A cell removed from an 8-cell mammalian embryo can develop into a normal late-stage embryo. This finding supports the idea that ______. A. there is no organizer in mammals B. the first three cell divisions do not result in an asymmetrical distribution of cytoplasmic determinants C. the cell lacked cytoplasmic determinants D. the first cleavage event must be transverse to the animal-vegetal axis of the zygote E. only the zygote is totipotent

B

If an egg cell contained EDTA, a chemical that binds calcium ions and magnesium ions, what effect would this have on fertilization? A) The fast block to polyspermy would not occur. B) The fertilization envelope would not be formed. C) The acrosomal reaction would be blocked. D) The fusion of sperm and egg nuclei would be blocked. E) The zygote would not contain maternal and paternal chromosome

B

If you were to observe the activity of methylated DNA, you would expect it to _______. A) be very active in translation. B) have turned off or slowed down the process of transcription. C) induce protein synthesis by not allowing repressors to bind to it. D) be unwinding in preparation for protein synthesis. E) be replicating.

B

In vertebrate embryos, the early stages of neural-tube formation is induced by chemical signals from ______. A) the dorsal lip of the blastopore. B) cells of the notocord. C) cells that will become the neural plate. D) neural-crest cells E) both A and B

B

Ribosomes and transfer RNAs are used during the process of ______. A. replication B. translation C. transcription D. mutation

B

The fact that a complete plant can be cloned from a somatic cell such as a stem or leaf or root cell demonstrates that ______. A) genes are lost during differentiation. B) differentiated cells retain all the genes of the zygote. C) the differentiated state is very stable. D) differentiation does not occur in plants. E) differentiated cells contain masked mRNA.

B

The process of cellular differentiation is a direct result of ______. A) apoptosis. B) differential gene expression. C) morphogenesis. D) differences in cellular genomes. E) cell division.

B

Which is true of transcription factors? A) They initiate the epinephrine response in animal cells. B) They control which genes are turned on to form mRNA. C) They regulate the synthesis of DNA in response to a signal. D) Some transcribe ATP into cAMP. E) They are needed to translate mRNA transcripts into protein.

B

What is the role of histone proteins in eukaryotic cells? A) They are part of the transition initiation complex. B) They help package DNA into a nucleus. C) They are a means of regulating gene expression. D) choices B and C only E) all of the above

B and C; they help package DNA into nucleus, and they are a means of regulation gene expression.

Transcription in eukaryotes requires which of the following in addition to RNA polymerase? A) codons and anticodons B) several transcription factors (Tfs) and DNA control elements C) ribosomes and tRNAs D) a pool of free amino acids E) histones

B) several transcription factors (Tfs) and DNA control elements

"Genomic equivalence" refers to the ______. A) similarity in genomes between males and females of the same species. B) organizational similarity of the genomes of all living organisms, reflecting their common ancestry. C) fact that all the somatic cells of an organism have identical genomes, regardless of their state of differentiation. D) similarity in genomes among all individuals of the same species. E) fact that all the cells of an organism express the same genes, regardless of differences in their genomes.

C

) Muscle is derived from _______. A.ectoderm B. endoderm C. mesoderm

C

The blastocoel in a sea-urchin blastula differs from that in a frog blastula because______. A) the urchin blastocoel is relatively smaller because cleavage is holoblastic in the urchin but meroblastic in the frog. B) the urchin blastocoel is relatively smaller because cleavage is meroblastic in the urchin but holoblastic in the frog. C) the urchin blastocoel is relatively larger because the urchin egg is microlecithal but the frog egg is mesolecithal. D) the urchin blastocoel is relatively larger because the urchin egg is mesolecithal but the frog egg is microlecithal. E) the urchin blastocoel is relatively larger because the urchin egg is macrolecithal but the frog egg is microlecithal.

C

Which of the following is an example of a possible step in the post-transcriptional control of gene expression? A. gene amplification during a stage in development B. the folding of DNA to form heterochromatin C. the removal of introns and splicing together of exons D. the binding of transcription factors to a promoter E. the addition of methyl groups to cytosine bases of DNA

C

Which of the following is true about the slow block to polyspermy in sea urchins? A. It can be reversed if a fertilization envelope fails to develop B. It is induced by a depolarization, or change in membrane potential, of the egg C. It provides a permanent block D. It is induced when acrosomal enzymes digest a path through the jelly coat E. It is slow to develop but lasts for only a minute

C

During fertilization, the acrosomal enzymes _____. A) block polyspermy B) help propel more sperm toward the egg C) digest the protective coat on the surface of the egg D) nourish the mitochondrion of the sperm E) trigger the completion of meiotic cell division by the sperm

C) digest the protective coat on the surface of the egg

The outermost embryonic germ layer is _____ and this eventually gives rise to the ______. A) endoderm; nervous system B) endoderm; digestive system C) ectoderm; nervous system D) ectoderm; digestive system E) ectoderm; musculo-skeletal system

C) ectoderm; nervous system

The vitelline layer of a sea urchin egg _____. A) is outside of the fertilization envelope B) releases calcium, which initiates the cortical reaction C) has receptor molecules that are specific for binding acrosomal proteins D) is first visible only when gastrulation is complete E) is a mesh of proteins embedded within the cytoplasm of the egg

C) has receptor molecules that are specific for binding acrosomal proteins

Which of the following statements is TRUE? a. Heterochromatin is composed of DNA, whereas euchromatin is made of DNA and RNA b. Both heterochromatin and euchromatin are found in the cytoplasm c. Heterochromatin is highly condensed, whereas euchromatin is less compact d. Euchromatin is not transcribed, whereas heterochromatin is transcribed e. Only euchromatin is visible under the light microscope

C. Heterochromatin is highly condensed, whereas euchromatin is less compact

As an embryo develops, new cells are formed and different types of cells develop by the process of ______. A) preformation and epigenesis. B) preformation and cell differentiation. C) preformation and morphogenesis. D) cell division and differentiation. E) differentiation and morphogenesis

D

In a nucleosome, what is the DNA wrapped around? A) polymerase molecules B) mRNA C) ribosomes D) histones E) nucleolus protein

D

In deuterostomes such as the sea urchin, frog, and human, the opening of the gut where the archenteron first starts to form becomes the ______. A. central nervous system B. notocord C. mouth

D

The primitive streak in a chick or human embryo is the functional equivalent of ______. A) neural crest cells in a mammal. B) the notochord in a mammal. C) the archenteron in a frog. D) the lip of the blastopore in the frog. E) polar bodies in a sea urchin.

D

Which developmental sequence is correct? A) gastrula, morula, blastula, cleavage B) morula, cleavage, gastrula, blastula C) cleavage, blastula, gastrula, morula D) cleavage, morula, blastula, gastrula E) cleavage, gastrula, morula, blastula

D

Which of the following serve as sources of developmental information? A) cytoplasmic determinants such as mRNAs and proteins produced before fertilization B) signal molecules produced by neighboring cells C) ubiquitous enzymes such as DNA polymerase and DNA ligase D) A and B only E) A, B, and C

D

Differences between human intestinal cells and heart-muscle cells can be explained by these cells ____. A) having different genes in their nuclei B) having different chromosomes C) using different genetic codes D) having different genes expressed E) having unique and different ribosomes

D) having different genes expressed

From the perspective of the cell receiving the message, the three stages of cell signaling are ______. A) signal activation, induction, and cellular response. B) signal reception, cellular response, and cell division. C) signal induction, activation, and cell repression. D) signal ingression, invagination, and involution. E) signal reception, signal transduction, and cellular response.

E

The cortical reaction of sea urchin eggs functions directly in the ________. A. fusion of egg and sperm nuclei B. release of hydrolytic enzymes from the sperm cell C. generation of an electrical impulse by the egg cell D. production of a fast block to polyspermy E. formation of a fertilization envelope

E

Which of the following is least related to the others? A) germ layers B) gastrulation C) invagination D) blastopore E) morula

E

A frameshift mutation could result from ________.

Either an insertion or deletion of a base.

A codon _______. a. may code for the same amino acid as another codon. b. consists of two nucleotides. c. consists of discrete amino acid regions. d. is found in all eukaryotes, but not in prokaryotes e. catalyzes RNA synthesis

May code for the same amino acid as another codon.

Which of the following represents a similarity between RNA and DNA? a. Both are double-stranded molecules b. The presence of uracil c. The presence of an OH group on the 2' carbon of the sugar d. Nucleotides consisting of a phosphate, a sugar, and a nitrogenous base e. Both are found exclusively in the nucleus

Nucleotides consisting of a phosphate, a sugar, and a nitrogenous base.

What occurs at the promoter region of DNA? A) DNA polymerase binds B) RNA polymerase binds C) the operator binds D) a repressor molecule binds E) an inducer molecule binds

RNA polymerase binds

It became apparent to Watson and Crick after completion of their model that the DNA molecule could carry a vast amount of hereditary information in its __________.

Sequence of bases

Hormone signals such as testosterone are involved in eukaryotic cell signaling pathways that typically involve _______. A) signal reception, followed by signal transduction and cellular response B) signal reception, followed by signal transduction and new cell generation C) replication, followed by transcription and translation D) signal transduction, followed by cellular response and cell division E) paracrine, local, and synaptic stages of gene expression

Signal reception, followed by signal transduction and cellular response.

The strands that make up DNA are antiparallel. This means that _________. A) the twisting nature of DNA creates nonparallel strands. B) one strand contains only purines and the other contains only pyrimidines. C) one strand is positively charged and the other is negatively charged. D) the 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand

The 5' to 3' direction of one strand runs counter to the 5' 3' direction of the other strand.

In both eukaryotes and prokaryotes, gene expression is primarily regulated at the level of: a. transcription b. translation c. mRNA stability d. mRNA splicing e. protein stability

a. transcription

A eukaryotic gene typically has all of the following features except ___________.

an anticodon

Access to a certain promoter site in DNA by RNA polymerase is restricted by histones. Which of the following processes will be most directly affected? a. recognition of the termination signal b. gene expression c. transfer of tRNA along the ribosome d. formation of the mitotic spindle

b. gene expression

In eukaryotes, transcription is generally associated with _____. A) euchromatin and histone acetylation B) euchromatin and histone methylation C) highly methylated DNA D) tightly packed DNA E) heterochromatin

euchromatin and histone acetylation

Which of the following statements is not true? A) Euchromatin is highly condensed, whereas heterochromatin is less compact. B) Heterochromatin is composed of DNA and associated proteins. C) Both euchromatin and heterochromatin contain DNA. D) Euchromatin is transcribed, whereas heterochromatin is not. E) Both heterochromatin and euchromatin are found in the nucleus.

euchromatin is highly condense, whereas heterochromatin is less compact

Once transcribed, eukaryotic mRNA typically undergoes substantial alteration that includes _____. A) linkage to histone molecules B) fusion into circular forms known as plasmids C) union with ribosomes D) fusion with other newly transcribed mRNA E) excision of introns 7. The tryptophan operon is a repressible

excision of introns

What are the protein-coding segments within a eukaryotic gene called? A) operons B) exons C) introns D) miRNAs E) codons

exons

In a nucleosome, what is the DNA wrapped around? A) mRNA B) a transcription initiation complex C) ribosomes D) histones E) RNA polymerase

histones

What is a codon part of? A) tRNA B) mRNA C) DNA D) a ribosome E) RNA polymerase

mRNA