Deck 19: Cellular Mechanisms of Development

Question 1

In general,the blastomeres of the_______ form the ectodermal tissues.

A)animal pole
B)vegetal pole
C)equator region
D)membrane

Answer 1

A

Question 2

Drosophila eggs acquire an initial asymmetry before fertilization as a result of

A)production of bicoid proteins in one end of the egg.
B)maternal DNA molecules being deposited in one end of the egg.
C)nurse cell migration to one end of the egg.
D)maternal mRNA being deposited in one end of the egg.
E)attachments of cadherins to one end of the cell.

Answer 2

D

Question 3

A hollow ball of cells that results from repeated cell divisions is called a

A)blastomere.
B)gastrula.
C)blastula.
D)somite.
E)imaginal disk.

Answer 3

C

Question 4

Many insects go through an elaborate development called metamorphosis.They move from a larval stage into a pupal stage and after a time emerge as an adult.Which of the following statements regarding this metamorphosis is true?

A)This metamorphosis involves the total rearrangement of all larval cells and contents,which are used in the growth and development of the adult.
B)This metamorphosis involves the partial rearrangement of some of the larval cells and contents,which are used in the growth and development of the adult.
C)This metamorphosis involves the total rearrangement of all pupal cells and contents,which are used in the growth and development of the adult.
D)This metamorphosis involves the absorption of nutrients from the pupal case prior to emerging as an adult insect.

Question 5

A zygote is a fertilized egg formed by an egg and a sperm.The zygote undergoes many mitotic events as it develops into a solid ball of cells called a blastomere.Select the correct statement that describes the condition of a blastomere.

A)During the initial cleavages,there is a tremendous increase in the number of cells and the cell size of the blastomeres.
B)During the initial cleavages,there is a tremendous decrease in the number of cells and the cell size of the blastomeres.
C)During the initial cleavages,there is a tremendous increase in the number of cells coupled with a decrease in the size of the cells composing the blastomeres.
D)During the initial cleavages,there is no increase in the number of cells of the blastomere,but the size of the cells increases.

Question 6

In insects,the passage from one body form to another is called ________.

A)pupation
B)ecdysis
C)metamorphosis
D)transference

Question 7

Very early in development,each cell is capable of expressing all its genes.This is referred to as

A)determination.
B)differentiation.
C)positional labels.
D)totipotency.
E)a chimera.

Question 8

A zygote divides into smaller cells,each called a

A)blastomere.
B)gastrula.
C)neurula.
D)cleavage cell.
E)embryonic cell.

Question 9

There are cases,particularly in fruit flies,in which a perfectly normal body part grows in an area where it should not grow.Extra pairs of wings and legs growing in the antennae location are some examples.Select the statement that best describes this phenomenon.

A)These mutations occur as a result of specialized development called determination in which the gene determining a specific factor will become totipotent.
B)These mutations occur as a result of differentiation of these tissues at the incorrect time during development,which causes a mix-up in signals and protein production in those tissues.
C)These mutations occur as a result of homeotic gene mutations.
D)These mutations occur as a result of gap gene mutations.

Question 10

The elongated structure that links the embryo of a developing plant to its nutrient source is called the

A)suspensor.
B)meristem.
C)vascular tissue.
D)imaginal connection.
E)syncytial blastoderm.

Question 11

________ are cell adhesion proteins that some cells use for movement during their development.

A)Cadherins
B)Glycospheres
C)Receptors
D)Phospholipids

Question 12

Plants have special groups of self-renewing cells called ________.

A)root cells
B)chloroplasts
C)cast cells
D)meristems

Question 13

________,the initial period of division in a zygote,is not accompanied by any increase in the overall size of the embryo.

A)Mitosis
B)Cleavage
C)Meiosis
D)Fertilization

Question 14

A fertilized egg is called a _____________.

A)zygote
B)ovule
C)oocyte
D)blastocyst

Question 15

Scientists attempted for many years to conduct nuclear transplants but failed.However,geneticists at the Roslin Institute in Scotland had success in cloning a sheep.They were successful because they

A)picked a cell very early in development.
B)replicated the blastomeres before insertion.
C)delayed transcription in the blastomeres.
D)treated the nucleus with sheep plasma before nuclear insertion.
E)utilized a new micro pipette techniquE.

Question 16

In general,the blastomeres of the_______ form the endodermal tissues.

A)animal pole
B)vegetal pole
C)equator region
D)membrane

Question 17

In Drosophila development,which of the following choices is true?

A)Paternal genes determine the initial course of the development after fertilization.
B)Zygotic genes determine the initial course of the development after fertilization.
C)Maternal genes determine the initial course of the development after fertilization.
D)Syncytial blastoderm genes determine the initial course of the development after fertilization.

Question 18

Plants do not utilize the process of cell migration in their development.Instead plants utilize

A)the process of building themselves inwardly via the meristems present in the developing plant tissues.
B)the process of building themselves outwardly via the meristems present in the developing plant tissues.
C)the process of building themselves with epidermal tissues,which eventually become ground tissues,which can then begin the process of photosynthesis.
D)the process of building themselves by using their vascular tissues to form meristems,which eventually cause normal development in the plant.

Question 19

In Drosophila,the initial cells created by cleavage contain different developmental signals from the egg called cytoplasmic _______.

A)stem cells
B)signals
C)determinants
D)junctions

Question 20

A seed germinates as a result of

A)a predetermined internal clock set in place at fertilization.
B)responses to changes in its environment.
C)having tolerated a long winter.
D)being planted at the correct time.
E)its genetics.

Question 21

Cells that are programmed to die,shrivel and shrink in a process called

A)apoptosis.
B)necrosis.
C)totipotency.
D)induction.
E)encoded death.

Question 22

The Drosophila homeotic genes typically contain the homeobox.The homeobox is a sequence of 180 nucleotides.This sequence codes for ______ amino acids.

A)30
B)60
C)90
D)120
E)180

Question 23

The finding that homeotic genes are present in both mammals and insects indicates that these genes must

A)control the same traits.
B)be on the same chromosomes.
C)have arisen very early in the evolutionary history of animals.
D)have developed simultaneously.
E)code for the exact same proteins.

Question 24

Which of the following statements regarding stem cells is false?

A)Totipotent stem cells can differentiate into any cell type in the body,except embryonic stem cells.
B)Pluripotent stem cells are descendants of the totipotent stem cells of the embryo.
C)A fertilized egg is a type of totipotent stem cell.
D)Pluripotent stem cells can differentiate into any cell type,except for totipotent stem cells and the cells of the placenta.

Question 25

Egg cells were combined with ______ to form the cloned sheep named Dolly.

A)skin cells
B)sperm cells
C)mucous membrane cells
D)mammary cells
E)ovarian cells

Question 26

Which genes are expressed in Drosophila after pattern formation along the A/P axis has been successfully established?

A)totipotent genes
B)bicoid genes
C)segment polarity genes
D)gap genes
E)homeotic genes

Question 27

In contrast to the cell cycle of adult somatic cells,the dividing cells of an early embryo lack which cell cycle stage(s)?

A)M
B)S
C)G₁ and G₂
D)interphase

Question 28

Which of the following statements regarding animal and vegetal poles is true?

A)When animal pole cells are cultured with vegetal pole cells,some of the animal pole cells become mesoderm.
B)When animal pole cells are cultured with vegetal pole cells,some of the vegetal pole cells become mesoderm.
C)Isolated animal cells develop as endoderm.
D)Isolated vegetal cells develop as ectoderm.

Question 29

In Drosophila,the initial cells formed by cleavage contain different determinants.The determinants direct the path of development.What type of development path is used by Drosophila?

A)regulative development
B)cleavage development
C)mosaic development
D)morphogen development
E)induction development

Question 30

A complete cell lineage map exists for

A)
B)Drosophila.
C)elegans.
C)mouse.
D)human.

Question 31

In Drosophila,different segmental fates of each neuroblast (cells that give rise to neurons)is determined by

A)gap genes.
B)pair-rule genes.
C)segment polarity genes.
D)homeotic genes.

Question 32

Cell transplantation experiments can be used to do all of the following except

A)to study the normal fate of cells.
B)to address the ability of cells to communicate with surrounding tissue.
C)to determine cell lineage.
D)to test the functional compatibility of cells between species.

Question 33

In a 32-cell stage tunicate embryo,vegetal marginal cells that lack functional genes for both macho-1 and the FGF receptor would develop as what cell type?

A)mesenchyme
B)muscle
C)notochord
D)nerve cord

Question 34

Which of the following proteins is associated with activating genes that code for the first mRNA transcribed in Drosophila embryos?

A)bax protein
B)cadherin protein
C)bicoid protein
D)nanos protein
E)morphogen protein

Question 35

A muscle precursor cell would be considered to be

A)pluripotent.
B)determined.
C)differentiated.
D)induceD.

Question 36

In a 32-cell stage tunicate embryo,if the vegetal marginal cells lack a functional FGF receptor,the development of which of the following structures would be affected?

A)the notochord and mesenchyme
B)the underlying endoderm
C)the overlying ectoderm
D)muscle cells

Question 37

Caenorhabditis elegans is an organism with exactly 959 somatic cells.This organism is a(n)

A)fruit fly.
B)earthworm.
C)nematode.
D)angiosperm.
E)fungus.

Question 38

In a cell transplantation experiment,one must

A)label the host cells with cell lineage or genetic markers.
B)label the donor cells with cell lineage or genetic markers.
C)label the host cells with a cell lineage marker and the donor cell with a genetic marker.
D)label the host cells with a genetic marker and the donor cell with a cell lineage marker.

Question 39

Signal molecules that determine relative positions during development are known as

A)inductors.
B)organizers.
C)cadherin domains.
D)determinants.
E)morphogens.

Question 40

Cells that die of injury usually swell and then burst.Their contents are released into the extracellular fluid.This form of cell death is referred to as

A)apoptosis.
B)necrosis.
C)totipotency.
D)induction.
E)encoded death.

Question 41

In

A)131 cells always die.
B)all 1090 cells die.
C)all 1090 cells live.
C)elegans ced-9/ced-3 double mutants
D)only 959 cells livE.

Question 42

A fly that expresses the bicoid mutant phenotype

A)is genetically wild-type,but has a bicoid mutant mother.
B)is mutant for bicoid and has a bicoid mutant mother.
C)may be either genetically wild-type or mutant for bicoid,but definitely has a bicoid mutant mother.
D)can be either genetically wild-type or mutant for bicoiD.The genotype of the mother cannot be determined from the information provideD.

Question 43

The term neoplasia refers to cell accumulation.Neoplasia can be caused by

A)increased apoptosis.
B)decreased apoptosis.
C)blood clots
D)cell membrane interactions

Question 44

A mutation in an integrin protein may result in all of the following except

A)an interruption in signal transduction.
B)defects in attachment of the cell to the extracellular matrix.
C)the failure to induce changes in gene transcription.
D)the failure to mediate Ca2⁺ binding.

Question 45

The offspring of which of the following organisms are most at risk for developmental defects due to endocrine-disrupting chemicals (EDCs)?

A)organisms at the top of the food chain
B)organisms at the bottom of the food chain
C)herbivores
D)omnivores
E)carnivores

Question 46

If a Drosophila mother is mutant for dorsal,her embryos would

A)develop normally.
B)have a delay in the development of dorsal/ventral polarity.
C)lack dorsal structures.
D)lack ventral structures.

Question 47

One piece of evidence suggesting that HOM and Hox genes are homologous is

A)that the mouse has twice as many Hox gene clusters as DrosophilA.
B)that the homeobox identifies the portion of the genome involved in pattern formation.
C)that the homeobox has been identified in primitive organisms.
D)their linear order of organization on chromosomes is the same in mouse and Drosophila.

Question 48

In plants,the main functions of MADS box-containing genes include all of the following except

A)the transition from vegetative to reproductive growth.
B)root development.
C)generation of leaf form.
D)floral organ identity.

Question 49

If one were to inject bicoid⁺ cytoplasm into the middle of a Drosophila egg immediately prior to fertilization,the embryo would

A)try to form anterior structures in the middle of its body.
B)try to form posterior structures in the middle of its body.
C)not develop at all.
D)develop normally.

Question 50

Which of the following best describes the apoptotic pathway in mammalian cells?

A)Bcl2 inhibits Apar1,Apaf1 activates Caspase-8 or 9,caspases degrade cell components
B)Bcl2 activates Apar1,Apaf1 inhibits Caspase-8 or 9,caspases degrade cell components
C)Bcl2 activates Apar1,Apaf1 activates Caspase-8 or 9,caspases degrade cell components
D)Apar1 inhibits Bcl2,Bcl2 activates Caspase-8 or 9,caspases degrade cell components

Question 51

Members of the Bcl-2 family all have Bcl-2 homology (BH)domains,which are essential for protein function.If one were to generate a transgenic worm that expresses a Bcl-2 protein containing a mutation in the BH domain in a ced-9 mutant background,

A)131 cells would die.
B)all 1090 cells would die.
C)all 1090 cells would live.
D)959 cells would live.

Question 52

Adult stem cells are usually

A)differentiated.
B)totipotent.
C)pluripotent.
D)multipotent.

Question 53

A mutation in a Hox gene typically results in

A)a transformation to anterior structures.
B)a transformation to posterior structures.
C)a segmental deletion.
D)legs growing out of the head of a fly.

Question 54

In Drosophila,the MADS box-containing gene,Mef2,is expressed in muscle precursor cells.In Mef2 mutants,these cells fail to develop into muscle fibers,and instead undergo apoptosis.Based on this information,and what you know about MADS box-containing genes,Mef2 plays a role in

A)determination of muscle precursors.
B)differentiation of muscle cells.
C)the initiation of apoptosis.
D)morphogenesis.

Question 55

The low success rate and age-related diseases associated with reproductive cloning is thought to be due to

A)genetic imprinting.
B)the age of the donor cell.
C)cell cycle problems.
D)large offspring syndrome (LOS).

Question 56

What was the most significant research finding that resulted from the successful cloning of Dolly?

A)The key to cloning success is to pick a donor cell from very early in development.
B)Cloned animals are capable of producing normal offspring.
C)The nucleus of a fully-differentiated cell can be reprogrammed to be totipotent.
D)Genetic imprinting,which occurs in adult reproductive tissue,can take months for sperm and years for eggs.

Question 57

The main difference between therapeutic cloning and reproductive cloning is that

A)in therapeutic cloning,embryonic stem cells are extracted from the blastocyst,while in reproductive cloning,the blastocyst is kept intact and implanted into a surrogate mother.
B)somatic cell nuclear transfer is used for therapeutic cloning,while gametic cell nuclear transfer is used in reproductive cloning,the blastocyst is kept intact and implanted into a surrogate mother.
C)unlike cells used for reproductive cloning,cells grown for therapeutic purposes do not display genetic imprinting problems.
D)unlike cells used for reproductive cloning,cells grown for therapeutic purposes do not require the destruction of embryos.

Question 58

Overexpression of caudal in the early Drosophila embryo,at a level high enough to overcome inhibition by bicoid protein,would

A)interfere with the development of anterior structures.
B)interfere with the development of posterior structures.
C)interfere with the development of both anterior and posterior structures.
D)have no effect since the cytoplasm has already been determineD.

Question 59

Which of the following represents the correct order of gene expression in the early Drosophila embryo?

A)pair-rule genes,gap genes,segment polarity genes
B)gap genes,pair-rule genes,segment polarity genes
C)gap genes,segment polarity genes,pair-rule genes
D)segment polarity genes,pair-rule genes,gap genes

Question 60

In Drosophila,the first mRNA to be transcribed after fertilization is

A)caudal.
B)hairy.
C)hunchback.
D)engraileD.