16 Development, Stem Cells, and Cancer

Initially, cytoplasmic determinants are localized in one part of a zygote and could be which of the following? (Choose more than one answer.) gene mRNA transcription factor ribosome myoblast Answer: B, C. © 2016 Pearson Education, Inc. 2

Initially, cytoplasmic determinants are localized in one part of a zygote and could be which of the following? (Choose more than one answer.) gene mRNA transcription factor ribosome myoblast © 2016 Pearson Education, Inc. 3

The shape of an organ, the number of brain cells in an embryonic brain, the removal of mutated cells, and the webbing cells between the toes of a human embryo are all regulated by which of the following? certain cells becoming much larger certain cells shrinking certain cells dying formation of embryonic cells concentration of Bicoid protein Answer: C. © 2016 Pearson Education, Inc. 4

The shape of an organ, the number of brain cells in an embryonic brain, the removal of mutated cells, and the webbing cells between the toes of a human embryo are all regulated by which of the following? certain cells becoming much larger certain cells shrinking certain cells dying formation of embryonic cells concentration of Bicoid protein © 2016 Pearson Education, Inc. 5

The photograph shows Rainbow and CC (CC is Rainbow’s clone) The photograph shows Rainbow and CC (CC is Rainbow’s clone). Why is CC’s coat pattern different from Rainbow’s given that CC and Rainbow are genetically identical? random X chromosome inactivation heterozygous at coat color gene locus environmental effects on gene expression all of the above Answer: D. See Figure 16.13. © 2016 Pearson Education, Inc. 6

The photograph shows Rainbow and CC (CC is Rainbow’s clone) The photograph shows Rainbow and CC (CC is Rainbow’s clone). Why is CC’s coat pattern different from Rainbow’s given that CC and Rainbow are genetically identical? random X chromosome inactivation heterozygous at coat color gene locus environmental effects on gene expression all of the above © 2016 Pearson Education, Inc. 7

Which of the following would not typically cause a proto-oncogene to become an oncogene? gene repression translocation amplification point mutation retroviral activation Answer: A. © 2016 Pearson Education, Inc. 8

Which of the following would not typically cause a proto-oncogene to become an oncogene? gene repression translocation amplification point mutation retroviral activation © 2016 Pearson Education, Inc. 9

Which of the following is not a likely example of induction? the optic cup of a tadpole brain signaling the overlaying epidermis to form a lens the anchor cell of a nematode signaling the overlaying epidermis to form the vulva the transcription factor MyoD activating target genes the heart mesoderm of a chick signaling the adjacent endoderm to form the liver Answer: C. Induction is a cell-to-cell or tissue-to-tissue interaction. Without knowing the details of any of these examples, students should be able to make this distinction. © 2016 Pearson Education, Inc.

Which of the following is not a likely example of induction? the optic cup of a tadpole brain signaling the overlaying epidermis to form a lens the anchor cell of a nematode signaling the overlaying epidermis to form the vulva the transcription factor MyoD activating target genes the heart mesoderm of a chick signaling the adjacent endoderm to form the liver © 2016 Pearson Education, Inc.

If cell type A induces cell type B to form cell type C, which of the following experimental results would not be expected? Removal of cell type A results in loss of cell type B. Removal of cell type A results in loss of cell type C. Removal of cell type B results in loss of cell type C. Additional cell type A results in additional cell type C. Answer: A. © 2016 Pearson Education, Inc.

If cell type A induces cell type B to form cell type C, which of the following experimental results would not be expected? Removal of cell type A results in loss of cell type B. Removal of cell type A results in loss of cell type C. Removal of cell type B results in loss of cell type C. Additional cell type A results in additional cell type C. © 2016 Pearson Education, Inc.

Liver cells in your body are different in many ways from nerve cells in your body. What is the fundamental reason for these differences? Liver cells and nerve cells have different genes. Nerve cells have more important genes than liver cells. Liver cells express different genes than nerve cells. Nerve cells are more active than liver cells. Answer: C. © 2016 Pearson Education, Inc.

Liver cells in your body are different in many ways from nerve cells in your body. What is the fundamental reason for these differences? Liver cells and nerve cells have different genes. Nerve cells have more important genes than liver cells. Liver cells express different genes than nerve cells. Nerve cells are more active than liver cells. © 2016 Pearson Education, Inc.

Apoptosis is a good explanation for all of the following phenomena except one. Which one? regression of tail tissue during frog metamorphosis formation of wings during fruit fly metamorphosis formation of interdigital space during mouse limb development loss of precisely 131 cells during nematode development Answer: B. Apoptosis is a form of programmed cell death. Without knowing the details of any of these examples, students should be able to distinguish cell death from non-cell death. © 2016 Pearson Education, Inc.

Apoptosis is a good explanation for all of the following phenomena except one. Which one? regression of tail tissue during frog metamorphosis formation of wings during fruit fly metamorphosis formation of interdigital space during mouse limb development loss of precisely 131 cells during nematode development © 2016 Pearson Education, Inc.

In fruit fly development, which of the following proteins should be considered a morphogen? the protein reaper, which signals apoptosis the protein Antennapedia, which helps determine appendage development the protein engrailed, which helps determine segmentation the protein dorsal, which specifies dorso-ventral patterning in a concentration-dependent manner Answer: D. Without knowing the details of any of these examples, students should be able to determine that morphogens act in concentration gradients. © 2016 Pearson Education, Inc.

In fruit fly development, which of the following proteins should be considered a morphogen? the protein reaper, which signals apoptosis the protein Antennapedia, which helps determine appendage development the protein engrailed, which helps determine segmentation the protein dorsal, which specifies dorso-ventral patterning in a concentration-dependent manner © 2016 Pearson Education, Inc.

Arrange the following terms describing cell fate as they would occur sequentially during normal development: pluripotent, determined, totipotent. pluripotent, determined, totipotent totipotent, pluripotent, determined totipotent, determined, pluripotent pluripotent, totipotent, determined Answer: B. © 2016 Pearson Education, Inc.

Arrange the following terms describing cell fate as they would occur sequentially during normal development: pluripotent, determined, totipotent. pluripotent, determined, totipotent totipotent, pluripotent, determined totipotent, determined, pluripotent pluripotent, totipotent, determined © 2016 Pearson Education, Inc.

In the Dolly sheep cloning experiment, which type of cell would the DNA of one of Dolly’s mammary cells most closely resemble? a mammary cell of her surrogate mother the oocyte of her surrogate mother a mammary cell of her cell donor the oocyte of her cell donor Answer: C. © 2016 Pearson Education, Inc.

In the Dolly sheep cloning experiment, which type of cell would the DNA of one of Dolly’s mammary cells most closely resemble? a mammary cell of her surrogate mother the oocyte of her surrogate mother a mammary cell of her cell donor the oocyte of her cell donor © 2016 Pearson Education, Inc.

Which statement most accurately compares the developmental potency of embryonic and adult stem cells? They have an equal, large potential. Embryonic stem cells have greater potential. Adult stem cells have greater potential. They have an equal, low potential. Answer: B. © 2016 Pearson Education, Inc.

Which statement most accurately compares the developmental potency of embryonic and adult stem cells? They have an equal, large potential. Embryonic stem cells have greater potential. Adult stem cells have greater potential. They have an equal, low potential. © 2016 Pearson Education, Inc.

With regard to oncogenes, which of the following mutations might contribute to cancer? loss of function of a cell cycle–promoting gene gain of function of a cell cycle–promoting gene loss of function of a cell cycle–inhibiting gene gain of function of a cell cycle–inhibiting gene Answer: B, C. © 2016 Pearson Education, Inc.

With regard to oncogenes, which of the following mutations might contribute to cancer? loss of function of a cell cycle–promoting gene gain of function of a cell cycle–promoting gene loss of function of a cell cycle–inhibiting gene gain of function of a cell cycle–inhibiting gene © 2016 Pearson Education, Inc.