BIO 117 Exam 3 Study Guide
When is a cell considered differentiated? - ANSWER:when a cell manufactures proteins that are specific
to a particular cell type
_____ is responsible for forming the three distinct layers during gastrulation. - ANSWER:Cell movement
(differential expansion)
The predominant mechanism driving cellular differentiation is the difference in gene _____. -
ANSWER:expression
Programmed cell death, apoptosis, plays a major role in all of the following developmental situations
except: _____. - ANSWER:growth of nerves and blood vessels into a body segment
Which observation shows that cellular differentiation does not involve changes in the genetic makeup of
cells? - ANSWER:A single root cell from an adult carrot can grow into an entire carrot plant.
Differential gene expression and apoptosis are key processes in development because they _____. -
ANSWER:offer an explanation as to how transcription controls development and how loss of specific cells
can facilitate formation of mature organs
How does the Bicoid protein provide positional information along the anterior-posterior axis of the fly
embryo? - ANSWER:It is present at high concentration at the anterior end and low concentration at the
posterior end.
What is the regulatory gene cascade triggered by Bicoid that leads to the differentiation of segments
along the anterior-posterior axis of the fly embryo? - ANSWER:segmentation genes→Hox
genes→effector genes
The anterior-posterior axis of most animals is determined by _____. - ANSWER:regulatory gene
expression in a concentration gradient from the anterior to the posterior end
The order of Hox genes on the Drosophila chromosome has been found to be conserved in other
animals. Moreover, these genes have been shown to be duplicated and changed in different organisms
that have different form. This indicates _____. - ANSWER:evolutionary changes in developmental
pathways are genetically based
Evolutionary theory has until recently stressed genetic mutations that alter protein amino acid
sequences as the major source of variation that leads to speciation. Evo-devo (evolutionary
developmental biology) offers a different understanding of the role of genetic change in evolution.
Which of the following statements best summarizes this understanding? - ANSWER:Similar genes are
found in most developing animal bodies; changes in the times and places they are expressed can lead to
phenotypic variation.
Which of these specialized sperm structures is most similar to a lysosome? - ANSWER:acrosome
Which of these features of an egg is NOT correctly matched with its description? - ANSWER:Cytoplasmic
determinants: form when sperm penetrate the egg.
When is a cell considered differentiated? - ANSWER:when a cell manufactures proteins that are specific
to a particular cell type
_____ is responsible for forming the three distinct layers during gastrulation. - ANSWER:Cell movement
(differential expansion)
The predominant mechanism driving cellular differentiation is the difference in gene _____. -
ANSWER:expression
Programmed cell death, apoptosis, plays a major role in all of the following developmental situations
except: _____. - ANSWER:growth of nerves and blood vessels into a body segment
Which observation shows that cellular differentiation does not involve changes in the genetic makeup of
cells? - ANSWER:A single root cell from an adult carrot can grow into an entire carrot plant.
Differential gene expression and apoptosis are key processes in development because they _____. -
ANSWER:offer an explanation as to how transcription controls development and how loss of specific cells
can facilitate formation of mature organs
How does the Bicoid protein provide positional information along the anterior-posterior axis of the fly
embryo? - ANSWER:It is present at high concentration at the anterior end and low concentration at the
posterior end.
What is the regulatory gene cascade triggered by Bicoid that leads to the differentiation of segments
along the anterior-posterior axis of the fly embryo? - ANSWER:segmentation genes→Hox
genes→effector genes
The anterior-posterior axis of most animals is determined by _____. - ANSWER:regulatory gene
expression in a concentration gradient from the anterior to the posterior end
The order of Hox genes on the Drosophila chromosome has been found to be conserved in other
animals. Moreover, these genes have been shown to be duplicated and changed in different organisms
that have different form. This indicates _____. - ANSWER:evolutionary changes in developmental
pathways are genetically based
Evolutionary theory has until recently stressed genetic mutations that alter protein amino acid
sequences as the major source of variation that leads to speciation. Evo-devo (evolutionary
developmental biology) offers a different understanding of the role of genetic change in evolution.
Which of the following statements best summarizes this understanding? - ANSWER:Similar genes are
found in most developing animal bodies; changes in the times and places they are expressed can lead to
phenotypic variation.
Which of these specialized sperm structures is most similar to a lysosome? - ANSWER:acrosome
Which of these features of an egg is NOT correctly matched with its description? - ANSWER:Cytoplasmic
determinants: form when sperm penetrate the egg.
