BSC2011 Unit I

145 terms by saraperez 

Ready to study?
Start with Flashcards

Create a new folder

Advertisement Upgrade to remove ads

without exams B, C, D & E

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

gene expression

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?
a. 220
b. 660
c. 780
d. 1000
e. 1220

220

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

heterochromatin is highly condensed, whereas euchromatin is less compact

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

transcription

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

tRNA

Which of the following pairs of cell types are genomically equivalent?
a. Mary's skin cell & a skin cell from Mary's mother
b. Mary's skin cell & Mary's egg cell
c. Mary's skin cell & Mary's pancreatic cell
d. Mary's skin cell & a skin cell from her sister

mary's skin cell & mary's pancreatic cell

Proteins that directly interact with & bind to genes & regulate gene expression are called _____.
a. enzymes
b. signal transducers
c. secondary messengers
d. receptors
e. transcription factors

transcription factors

Genes in methylated regions of DNA are _____.
a. being expressed
b. being transcribed
c. being translated
d. inactivated
e. both choices A and B

inactivated

What is the correct sequence for steps in the scientific process?
1. confirm/revise hypothesis
2. experiment/test
3. formulate a hypothesis
4. make a prediction
5. ask a question
a. 5, 3, 2, 4, 1
b. 5, 4, 3, 2, 1
c. 4, 3, 5, 2, 1
d. 5, 3, 4, 2, 1
e. 4, 5, 3, 2, 1

ask a question
formulate a hypothesis
make a prediction
experiment/test
confirm/revise hypothesis

What process was used to clone Dolly the sheep? (FYI: a "ewe" is a female sheep)
a. Reprogramming the genes of just the egg cell from one ewe in a test tube and implanting the resulting cell into a surrogate mother's uterus.
b. Allowing an egg cell and enucleated sperm cell to fertilize in a test tube and implanting the resulting zygote into a surrogate mother's uterus.
c. Re-programming the genes in a differentiated body cell from one ewe in a test tube and implanting the cell into a surrogate mother's uterus.
d. Inserting the nucleus from a differentiated body cell of one ewe into an enucleated egg from another ewe, then reinserting the resulting embryo into a surrogate mother's uterus.
e. Re-programming the genes of a ewe's bone marrow stem cell in a test tube and implanting the transformed cell into a surrogate mother's uterus.

inserting the nucleus from a differentiated body cell of one ewe into an enucleated egg from another ewe, then reinserting the resulting embryo into a surrogate mother's uterus

The majority of genes in an organism's genome code for _____.
a. tRNA molecules
b. proteins
c. carbohydrates
d. rRNA
e. none of these

proteins

An embryologist observes that a single cell removed from an embryo cannot on its own develop into a normal embryo. What is the most likely reason for this?
a. The cell is multipotent. b. The cell is totipotent.
c. The cell is pluripotent.
d. No cytoplasmic determinants were deposited in the egg.
e. Choices A & D apply.

the cell is pluripotent

Molecule "A" activates a cell-membrane G-protein-linked receptor that in turn brings about the activation of an intracellular enzyme. Molecule "A" in this case serves as a(n)_____.
a. gene regulator
b. transcription factor
c. cytoplasmic determinant
d. signal
e. protein kinase

signal

A single DNA molecule corresponds to a _______.
a. gene
b. transcription unit
c. chromosome
d. protein
e. transcription factor

chromosome

Which of the following mutations is most likely to result in a serious error in protein synthesis?
a. a nucleotide substitution in the third nucleotide base of a codon
b. a nucleotide insertion
c. a nucleotide deletion
d. choices A, B and C are equally likely
e. choices B and C are more likely than choice A

a nucleotide insertion or deletion is more likely than a nucleotide substitution

The genetic code consists of _____.
a. 3 DNA codons representing an amino acid
b. 3 mRNA codons representing an amino acid
c. 3 tRNA codons representing an amino acid
d. one tRNA codon representing an amino acid
e. one mRNA codon representing an amino acid

one mRNA codon representing an amino acid

A researcher synthesizes a miRNA molecule with a specific nucleotide sequence based on her knowledge of a particular gene. She inserts the miRNA into a cell. She does this in order to _____.
a. increase transcription of that gene b. block expression of that gene c. locate the gene's position on a chromosome
d. increase translation of the gene's transcript
e. none of the above

block expression of that gene

What is a hypothesis?
a. a fact based on qualitative data that is testable
b. the same thing as an unproven theory
c. a verifiable observation sensed directly, or sensed indirectly with the aid of scientific instrumentation
d. a fact based on quantitative data that is falsifiable
e. a tentative explanation that can be tested and is falsifiable

a tentative explanation that can be tested and is falsifiable

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 _____________.
a. antiparallel backbones
b. different five-carbon sugars
c. phosphate-sugar backbones
d. sequence of bases
e. complementary pairing of bases

sequence of bases

Using RNA as a template for protein synthesis instead of translating proteins directly from the DNA is advantageous for the cell because ________________.
a. RNA is double-stranded and much more stable than DNA
b. RNA acts as an expendable copy of the genetic material, allowing the DNA to serve as a permanent, pristine repository of the genetic material
c. many mRNA molecules can be transcribed from a single gene, increasing the potential rate of gene expression
d. B and C only
e. A, B, and C

B and C only

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

both a 5' cap and a poly-A tail

A frameshift mutation could result from ____________.
a. a base deletion only.
b. deletion of three consecutive bases.
c. a base insertion only.
d. either an insertion or a deletion of a base.
e. a base substitution only.

either an insertion or a deletion of a base.

All of the following are made up of nucleic acid except a _____________.
a. promoter
b. control element
c. transcription factor
d. structural gene
e. regulatory gene

transcription factor

Muscle cells and nerve cells in one species of animal owe their differences in structure to ____.
a. having different genes.
b. differential gene expression
c. having different chromosomes
d. having unique ribosomes
e. using different genetic codes

differential gene expression

A eukaryotic gene typically has all of the following features except _________.
a. a terminator
b. introns
c. an anticodon
d. control elements
e. a promoter

an anticodon

In eukaryotes, transcription can occur for ___________.
a. both euchromatin and histone acetylation
b. euchromatin only.
c. highly methylated DNA only.
d. very tightly packed DNA only
e. heterochromatin only

both euchromatin and histone acetylation

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

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' to 3' direction of the other strand.

What are the protein-coding segments within a eukaryotic gene called?
a. operons
b. exons
c. introns
d. miRNAs
e. codons

exons

What is an anticodon part of?
a. tRNA
b. mRNA
c. DNA
d. a ribosome
e. RNA polymerase

tRNA

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

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

excision of introns

RNA polymerase binds to DNA at a region called a(n) __________.
a. operator
b. inducer
c. promoter
d. repressor
e. co-repressor

promoter

In a nucleosome, what is the DNA wrapped around?
a. mRNA
b. a transcription initiation complex
c. ribosomes
d. histones
e. RNA polymerase

histones

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 concerning reproductive cloning (e.g., Dolly) is true?
a. The cloned offspring is genomically equivalent to the surrogate mother who received the transplanted embryo.
b. The cloned embryo develops after a pluripotent donor nucleus and the nucleus from a surrogate mother's
egg cell fuse.
c. The cloned embryo develops after a totipotent donor nucleus and the nucleus from a surrogate mother's egg cell fuse.
d. The cloned embryo develops after a totipotent donor nucleus is implanted into an enucleated egg cell from a surrogate mother.
e. The cloned embryo develops after a pluripotent donor nucleus is implanted into an enucleated egg cell from a surrogate mother.

The cloned embryo develops after a totipotent donor nucleus is implanted into an enucleated egg cell from a surrogate mother.

Which of the following represents a similarity between RNA and DNA?
a. the presence of uracil
b. nucleotides consisting of phosphate, sugar, and nitrogenous-base components
c. Both are double-stranded.
d. Both are found exclusively in the nucleus.
e. Introns are spliced from both post-transcriptionally.

nucleotides consisting of phosphate, sugar, and nitrogenous-base components

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

What are the non-protein-coding segments within a eukaryotic gene called?
a. operons
b. exons
c. introns
d. miRNAs
e. codons

introns

What is a codon part of?
a. tRNA
b. mRNA
c. DNA
d. a ribosome
e. RNA polymerase

mRNA

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, nucleus disintegration, and new cell generation

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

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

they help package DNA into a nucleus AND they are means of regulating gene expression.

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 condensed, whereas heterochromatin is less compact.

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

they are genomically equivalent.

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

gastrulation; archenteron

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

several transcription factors (TFs) and DNA control elements

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

membrane depolarization

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

has receptor molecules that are specific for binding acrosomal proteins

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

having different genes expressed

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

the molecule's different 5-carbon sugars

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

the acrosomal reaction

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

ectoderm; nervous system

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

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

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

DNA > RNA > proteins

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

digest the protective coat on the surface of the egg

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

embryonic germ layers would not form

Which of the following pairs of cell types are genomically equivalent?
a. Joe's muscle cell & a muscle cell from Joe's father
b. Joe's muscle cell & Joe's sperm cell
c. Joe's muscle cell & Joe's brain cell d. Joe's muscle cell & a muscle cell from his sister

joe's muscle cell & joe's brain cell

Humans belong to the ____ lineage of animals that exhibit _____ embryonic cleavage.
a. protostome; radial
b. protostome; spiral
c. deuterostome; radial
d. deuterostome; spiral

deuterostome; radial

A blastula-stage embryo is likely to have a reduced blastocoel if the female gamete was _____.
a. mesolecithal
b. zygotic
c. holoblastic
d. determinate

mesolecithal

The outer-to-inner pattern of the different germ-tissue layers that comprise an animal embryo is _____.
a. mesoderm -ectoderm -endoderm
b. mesoderm -endoderm -ectoderm
c. endoderm -mesoderm -ectoderm
d. ectoderm -mesoderm -endoderm

ectoderm -mesoderm -endoderm

Which of the following accurately distinguishes a pluripotent human cell from a totipotent human 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

determination has progressed further in the pluripotent cell

Loosely packaged DNA such as _____ is more likely to be _______.
a. Euchromatin; transcribed
b. Euchromatin; translated
c. Heterochromatin; transcribed
d. Heterochromatin; translated

euchromatin; transcribed

What term describes molecules present in an unfertilized egg cell that function as signals that direct early embryonic development?
a. G-proteins
b. cytoplasmic determinants
c. acrosomal proteins
d. yolk
e. tRNAs

cytoplasmic determinants

What occurs most immediately after fertilization?
a. zygote growth
b. zygote cleavage
c. blastula growth
d. blastula cleavage
e. zygote differentiation

zygote cleavage

The hollow tube that forms inside an embryo during embryonic gastrulation is called the _______.
a. coelom
b. blastocoel
c. gastrocoel
d. archenteron
e. primitive streak

archenteron

Which of the following most directly serves to establish the fertilization envelope?
a. hydrolytic enzymes b. the acrosomal reaction c. the cortical reaction
d. bindin
e. bicoid

the cortical reaction

The outer-to-inner pattern of the different germ-tissue layers that comprise an animal embryo is _____.
a. mesoderm - ectoderm - endoderm
b. mesoderm - endoderm - ectoderm
c. endoderm - mesoderm - ectoderm
d. ectoderm - mesoderm - endoderm
e. ectoderm - endoderm - mesoderm

ectoderm - mesoderm - endoderm

The blastopore opening is formed in a sea urchin embryo by _______.
a. ingression of primary mesenchyme cells b. involution of primary mesenchyme cells
c. invagination of the fertilization envelope
d. involution of the zygote cell membrane
e. invagination of surface cells

invagination of surface cells

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

determination has progressed further in the multipotent cell

For a molecular signal to evoke a specific cellular response, it must first interact with a(an) ________.
a. receptor
b. transducer
c. gene
d. transfer RNA molecule
e. enzyme

receptor

Mutations in an organism's Hox genes would likely result in the improper development of _____.
A. the notochord
B. the spinal cord
C. the spinal column
D. the archenteron
E. appendages

appendages

Heterochrony involves ____.
A. changes in the timing of developmental-gene expression
B. changes in the proteins coded for by some developmental genes
C. changes in an organism's appearance during development due to environmental stimuli
D. choices A & B & C apply
E. none of the above

changes in the timing of developmental-gene expression

A rod of mesodermal tissue under the dorsal surface of a late frog gastrula is called the ____.
A. notochord
B. archenteron
C. dorsal lip
D. neural plate
E. limb bud

notochord

Codon-anticodon recognition and binding occurs between ______.
A. mRNA and tRNA
B. tRNA and an amino acid
C. DNA and mRNA
D. mRNA and an amino acid
E. DNA and tRNA

mRNA & tRNA

All of the following describe types of cell movement and rearrangement in embryos except _____.
A) convergent extension
B) ingression
C) induction
D) involution
E) invagination

induction

What permits a sperm to penetrate an egg's outer jelly coat?
A. acrosomal bindin proteins produced by the egg
B. acrosomal hydrolytic enzymes produced by the egg
C. acrosomal bindin proteins produced by the sperm
D. acrosomal hydrolytic enzymes produced by the sperm
E. Both choices A and C apply.

acrosomal hydrolytic enzymes produces by the sperm

Endodermal cells can bind to other endodermal cells as well as ____ cells in a gastrula because of similar _____.
A. ectodermal; morphogens B. mesodermal; cadherins
C. ectodermal; cytoplasmic determinants
D. mesodermal; genes
E. ectodermal; cadherins

mesodermal; cadherins

UnitI-1:
Yolk-rich cells are found in the region closest to the line leading to number _____.
A. 1 B. 2 C. 3 D. 4

4

UnitI-1:
The Spemann-Mangold organizer region of cells is closest to the line leading to number _____.
A. 1 B. 2 C. 3 D. 4

3

UnitI-1:
The space to which the line from #2 points is called the _____.
A) yolk sac
B) archenteron
C) perivitelline space
D) blastocoel
E) blastopore

blastocoel

What role does a morphogen play in embryonic development?
A) different genes get regulated depending on a morphogen's concentration in embryonic cells
B) a morphogen coordinates the correct placement of embryonic features
C) a morphogen induces embryonic cells to differentiate
D) only A and B apply
E) A, B and C apply

A, B and C apply

Which is true of hormones?
A. a particular hormone targets one particular type of cell or tissue
B. a particular hormone can affect gene regulation in multiple types of tissues
C. hormones serve as protein kinases in signal transduction pathways
D. hormone signals from one cell induce changes in adjacent (neighboring) cells
E. all of the above

a particular hormone can affect gene regulation in multiple types of tissues

The genetic code consists of _____.
A) 1 DNA anticodon representing an amino acid
B) 3 mRNA codons representing an amino acid
C) 3 tRNA anticodons representing an amino acid
D) one tRNA codon representing an amino acid
E) one mRNA codon representing an amino acid

one mRNA codon representing an amino acid

Loosely packaged DNA such as _____ is/are more likely to be _______.
A) euchromatin; transcribed B) euchromatin; translated C) heterochromatin; transcribed
D) heterochromatin; translated E) nucleosomes; translated

euchromatin; transcribed

UnitI-2:
The gastrulation event represented in the figure above is called _____.
A. invagination
B. convergent extension
C. involution
D. ingression
E. elongation

ingression

UnitI-2:
The arrow is pointing to a cell that will give rise to which germ layer?
A. endoderm
B. ectoderm
C. blastoderm
D. mesoderm
E. neural ectoderm

mesoderm

UnitI-2:
The cell to which the arrow is pointing is isolated from neighboring cells possibly because of a change in the expression of genes coding for what type of molecule?
A. bicoid
B. bindin
C. a cortical enzyme
D. a morphogen
E. a cadherin

a cadherin

A researcher synthesizes a miRNA with a specific nucleotide sequence based on her knowledge of a particular protein-coding gene. She then inserts the miRNA into a cell. She does this in order to _____.
A) increase transcription of that gene
B) block translation of that gene's transcript
C) identify the gene's location on a particular chromosome
D) block transcritpion of that gene
E) none of the above

block translation of that gene's transcription

Proteins may serve as all of the following but not as ____.
A) hormones
B) a source of genetic information
C) signal receptors
D) transport molecules E) enzymes

a source of genetic information

Which is an accurate comparison between a blastula and a morula?
A) they are roughly equivalent in overall size
B) the cells comprising a morula are smaller
C) the blastocoel in a morula is smaller
D) only a blastula has primary germ layers
E) a blastula has fewer cells

they are roughly equivalent in overall size

Metabolic wastes are collected in a sac formed by which extra-embryonic membrane?
A) chorion
B) vitelline
C) yolk-sac
D) amnion
E) allantois

allantois

In vertebrates with forelimbs (arms, wings, etc.), cells of the apical epidermal ridge organizer are responsible for _____.
A) directing the proper anterior-posterior arrangement of limb bones
B) directing the proper location of neural tube formation
C) directing the proper location of invagination during early gastrulation
D) directing the proper proximal-distal arrangement of limb bones
E) directing the proper anterior-posterior body axis of the embryo

directing the proper proximal-distal arrangement of limbs and bones

Digits remain joined in the webbed feet of ducks because ___.
A) caderin expression is blocked B) apoptosis is blocked
C) bicoid gene expression is blocked
D) choices A and B apply E) choices A, B and C apply

apoptosis is blocked

A biologist observes that the small Florida Keys deer can mate with northern white-tail deer but do not produce any offspring. This most likely explanation is that _____.
A) the gametes of both types of deer have incompatible cytoskeletal microtubules
B) the eggs of both types of deer have different cell-membrane receptors
C) the gametes of both types of deer have different amounts of yolk
D) there is too drastic a difference in size between the egg of one type of deer and sperm of the other
E) the gametes of both types of deer have incompatible cytoplasmic determinants

the eggs of both types of deer have different cell-membrane receptors

Which of the following are NOT components of signal transduction?
A. hormone molecules
B. G-proteins
C. cyclic AMP
D. protein kinases
E. protein phosphatases

hormone molecules

Which of the following is NOT an example of developmental plasticity?
A. A type of sunfish coexisting with large-mouth bass have more numerous spines along their back than when they coexist with small-mouth bass.
B. One species of finch on an island has a large stout beak to crack big, tough seeds and a second species on the island has a small beak to eat small seeds.
C. Grey tree squirrels living in Canada have thicker fur than their counterparts living in Florida.
D. The leaves of a species of flowering violet growing in an open field have more reflective hairs than ones growing in a shaded forest.
E. All of these are accurate examples of developmental plasticity.

one species of finch on an island has a large stout beak to crack big, tough seeds and a second species on the island has a small beak to eat small seeds.

The "genetic information" contained within a gene resides in its ______.
A. sequence of amino acids B. sugar-phosphate chain C. sequence of ribonucleotide bases
D. double helix
E. sequence of deoxyribonucleotide bases

sequence of deoxyribonucleotide bases

The experiment of Spemann and Mangold demonstrated _____.
A. that the dorsal lip is an organizer that induces the development of germ layers in a frog gastrula
B. that maternal genes produce morphogens that induce the development of anterior features on a gastrula embryo
C. that cells transplanted from the dorsal lip of a frog gastrula will induce the development of dorsal embryonic features
D. that the dissociated cells of a frog gastrula can re-aggregate in the correct germ-layer orientation
E. that the grey crescent is an organizer that directs the site of invagination in a frog gastrula

the cells transplanted from the dorsal lip of a frog gastrula will induce the development of dorsal embryonic features

If one or more mutations interfere with proper gene regulation in somites, which of the following might be affected adversely?
A) peripheral nerves coming off the spinal cord
B) neural tube formation
C) formation of vertebrae
D) cadherin expression in neural ectoderm
E) spinal cord formation

formation of vertebrae

What effect does the amount of yolk in a mesolecithal egg have on subsequent development?
A) the resulting blastula has a reduced blastocoel offset toward the vegetal pole
B) invagination forms a primitive streak rather than a blastopore
C) it prevents the formation of a blastocoel but not an archenteron
D) the yolk slows cell division and becomes unevenly distributed among the cells of the resulting blastula
E) it restricts invagination to the blastoderm region of an embryo

the yolk slows cell division and becomes unevenly distributed among the cells of the resulting blastula

Please match the three types of germ tissue listed below (A, B and C) with the organ(s) each type of germ tissue can form. Choices may be used more than once or not at all. A. endoderm
B. ectoderm
C. mesoderm
1. ribs
2. brain
3. liver
4. lungs
5. skin

ribs- mesoderm
brain- ectoderm
liver- endoderm
lungs- endoderm
skin- ectoderm

Which of the following terms are correctly paired?
A. macrolecithal egg & macroblastic cleavage
B. mesolecithal egg & meroblastic cleavage
C. mircolecithal egg & mesoblastic cleavage
D. mesolecithal egg & holoblastic cleavage
E. hololecithal egg & microblastic cleavage

mesolecithal egg & holoblastic cleavage

What role does the protein called bicoid play in Drosophila (fruit fly) development?
A) it is a cytoplasmic determinant and directs neurulation in the fly embryo
B) it is a cytoplasmic determinant that helps establish the anterior-posterior axis of the fly embryo
C) it is a cell adhesion molecule and induces neurulation in the fly embryo
D) it is a cytoplasmic determinant and establishes the dorsal-ventral axis of the fly embryo
E) all of the above

it is a cytoplasmic determinant that helps establish the anterior-posterior axis of the fly embryo

UnitI-3:
Which letter is pointing to a bindin receptor?

E

UnitI-3:
Which letter is pointing to the acrosome?

A

UnitI-3:
Which letter is pointing to a cortical granule?

C

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.

most signal receptors are bound to the outer membrane enclosing the nucleus

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

A and B only

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.

the lip of the blastopore in the frog

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

a nervous system

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

gastrulation

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

chorion

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

mesoderm

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

morula

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

it provides a permanent block

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

cleavage, morula, blastula, gastrula

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.

increases as the size of the cells decreases

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 chromosomes.

the fertilization envelope would not be formed

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

formation of a fertilization envelope

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

cells of the notocord

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.

the urchin blastocoel is relatively larger because the urchin egg is microlecithal but the frog egg is mesolecithal

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.

differential 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

dorsal lip of the blastopore

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.

totipotent

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.

differentiated cells retain all the genes of the zygote

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.

cytoskeletal microtubules

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

translation

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

cell division and differentiation

"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.

fact that all somatic cells of an organism have identical genomes, regardless of their state of differentiation

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

the removal of introns and splicing together of exons

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.

convergent extension

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. anus
E. coelom

anus

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.

they are all produced by the same gene

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.

signal reception, signal transduction, and cellular response

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

histones

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.

only the daughter cell with the gray crescent will develop normally

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.

embryonic stem cells can be totipotent, and adult stem cells are multipotent

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

excision of introns

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

the first three cell divisions do not result in an asymmetrical distribution of cytoplasmic determinants

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

they control which genes are turned on to form mRNA

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 be reprogrammed

it showed that genes in differentiated adult cells of mammals can be reprogrammed

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

anterior structures would form in both sides of the embryo

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again

Example:

Reload the page to try again!

Reload

Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording

Create Set