Question 1

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

Accepted Answer

A)  fruit fly.
B)  earthworm.
C)  nematode.
D)  angiosperm.
E)  fungus.F) All of the above
G) B) and C)

Question 2

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

Accepted Answer

A)  animal pole
B)  vegetal pole
C)  equator region
D)  membraneE) B) and C)
F) C) and D)

Question 3

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

Accepted Answer

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.E) None of the above
F) C) and D)

Question 4

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

Accepted Answer

A)  30
B)  60
C)  90
D)  120
E)  180F) B) and E)
G) B) and D)

Question 5

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

Accepted Answer

A)  animal pole
B)  vegetal pole
C)  equator region
D)  membraneE) None of the above
F) B) and D)

Question 6

Signal molecules that determine relative positions during development are known as

Accepted Answer

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

Question 7

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

Accepted Answer

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

Question 8

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

Accepted Answer

A)  root cells
B)  chloroplasts
C)  cast cells
D)  meristemsE) A) and B)
F) A) and C)

Question 9

A mutation in a Hox gene typically results in

Accepted Answer

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.E) All of the above
F) A) and C)

Question 10

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.

Accepted Answer

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.E) All of the above
F) B) and D)

Question 11

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

Accepted Answer

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

Question 12

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

Accepted Answer

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

Question 13

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

Accepted Answer

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.E) All of the above
F) B) and C)

Question 14

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

Accepted Answer

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.E) A) and B)
F) B) and D)

Question 15

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?

Accepted Answer

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.E) A) and B)
F) A) and C)

Question 16

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

Accepted Answer

A)  pupation
B)  ecdysis
C)  metamorphosis
D)  transferenceE) A) and B)
F) C) and D)

Question 17

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

Accepted Answer

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.E) A) and C)
F) B) and C)

Question 18

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

Accepted Answer

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.F) B) and E)
G) B) and C)

Question 19

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

Accepted Answer

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.E) All of the above
F) A) and D)

Question 20

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

Accepted Answer

A)  caudal.
B)  hairy.
C)  hunchback.
D)  engraileD.E) All of the above
F) A) and D)

Exam 19: Cellular Mechanisms of Development

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Signal molecules that determine relative positions during development are known as

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

A mutation in a Hox gene typically results in

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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