Question 1

Relate the study of embryonic chickens to the discovery of trophic factors.

Accepted Answer

The study of embryonic chickens has played a significant role in the discovery and understanding of trophic factors, which are molecules that support the growth, differentiation, and survival of cells and tissues. The embryonic chicken, particularly the chicken embryo's nervous system, has been a classic model organism in developmental biology and neurobiology for several reasons:

1. Accessibility: Chicken eggs are easily obtained and can be incubated outside the mother. This accessibility allows researchers to manipulate and observe the developing embryo in a controlled environment.

2. Developmental stages: The stages of chicken embryonic development are well-characterized, which makes it easier for scientists to study specific processes at precise times during development.

3. Size: The relatively large size of the chicken embryo compared to other model organisms, like fruit flies or nematodes, allows for easier dissection and manipulation of tissues.

4. Similarity to mammals: While there are differences, the basic processes of development and the overall organization of the nervous system in chickens are similar to those in mammals, making it a relevant model for human biology.

The discovery of trophic factors in the context of embryonic chickens is closely associated with the work on nerve growth factor (NGF). In the 1950s, Rita Levi-Montalcini and her colleague Stanley Cohen conducted seminal research using chicken embryos to investigate the development of the nervous system. They observed that when mouse tumor tissues were implanted into chicken embryos, the sensory and sympathetic nerve fibers grew profusely around the tumor. This led to the hypothesis that the tumor was releasing a substance that promoted nerve growth.

Levi-Montalcini and Cohen went on to isolate and characterize this substance, which they named nerve growth factor (NGF). NGF was the first trophic factor to be discovered and is essential for the growth and survival of certain types of neurons during development. It also maintains neuronal function in the adult nervous system.

The discovery of NGF opened the door to the identification of other trophic factors, such as brain-derived neurotrophic factor (BDNF), ciliary neurotrophic factor (CNTF), and glial cell line-derived neurotrophic factor (GDNF), among others. These factors are crucial for various aspects of cell development and maintenance, including neurons and other cell types.

In summary, the study of embryonic chickens has been instrumental in the discovery of trophic factors, starting with the groundbreaking work on NGF. This research has not only advanced our understanding of developmental biology and neurobiology but has also had significant implications for the treatment of neurodegenerative diseases and injuries, where trophic factors are explored as potential therapeutic agents.

Question 2

Choose 4 proteins that are important for nervous system development and organize them into a chart, with the name of the protein in one column, its function in another column, and experimental evidence that supports this function in a third column.

Accepted Answer

Protein Name | Function | Experimental Evidence
-----------------------------------------------------
1. Sonic Hedgehog (SHH) | Regulation of cell differentiation and proliferation in the developing nervous system | Experimental studies have shown that mutations in the SHH gene lead to neural tube defects and abnormal brain development in animal models and human patients.
2. Brain-Derived Neurotrophic Factor (BDNF) | Promotion of neuronal survival, differentiation, and synaptic plasticity | Research has demonstrated that BDNF knockout mice exhibit impaired neuronal development and function, leading to cognitive and behavioral deficits.
3. Notch | Regulation of neural stem cell maintenance and differentiation | Studies have shown that Notch signaling is essential for the maintenance of neural stem cells and the generation of diverse neuronal cell types during embryonic development.
4. Neurogenin | Induction of neuronal differentiation and specification of neuronal subtypes | Experimental evidence has revealed that Neurogenin knockout mice display severe defects in neuronal differentiation and fail to generate specific neuronal subtypes in the developing nervous system.

Question 3

You are a researcher studying neurogenesis. You artificially lower the amount of beta-catenin expressed in neural progenitor cells. Which of the following would be likely to result?

Accepted Answer

A)  neurogenesis onset would occur sooner than normal 
B)  neurogenesis onset would occur later than normal 
C)  neurogenesis onset would result in less delta-1 being produced 
D)  neurogenesis onset would occur in skin tissue 
A)  neurogenesis onset would occur sooner than normal 
B)  neurogenesis onset would occur later than normal 
C)  neurogenesis onset would result in less delta-1 being produced 
D)  neurogenesis onset would occur in skin tissue A

Question 4

Predict what would happen if a gene necessary for the expression of ephrin was mutated so that it becomes non-functional.

Accepted Answer

A)  Nasal axons would grow toward the rostral and caudal tectum 
B)  Nasal axons would only grow toward the rostral tectum only 
C)  Nasal axons would grow toward the caudal tectum only 
D)  Nasal axonal growth would be inhibited 
A)  Nasal axons would grow toward the rostral and caudal tectum 
B)  Nasal axons would only grow toward the rostral tectum only 
C)  Nasal axons would grow toward the caudal tectum only 
D)  Nasal axonal growth would be inhibited

Question 5

You are a researcher studying development. In an experiment, you examine the proteins present in the two cells that arise from a single fertilized frog egg. You are most likely to find that

Accepted Answer

A)  the genes found in each cell are different 
B)  transcription factors and other proteins found in each cell are completely different 
C)  some transcription factors and proteins are the same; some are different 
D)  cells don't express transcription factors and other proteins at the two-cell stage of development 
A)  the genes found in each cell are different 
B)  transcription factors and other proteins found in each cell are completely different 
C)  some transcription factors and proteins are the same; some are different 
D)  cells don't express transcription factors and other proteins at the two-cell stage of development

Question 6

A candidate molecule for establishing the dorsal-ventral organization of the early nervous system is

Accepted Answer

A)  BMP 
B)  SHH 
C)  chordin 
D)  none of the above 
A)  BMP 
B)  SHH 
C)  chordin 
D)  none of the above

Question 7

Analyze figure 4.20. In the text What is NOT true regarding the process depicted in these photomicrographs?

Accepted Answer

A)  netrin is acting as a chemoattractant 
B)  filopodia are able to adhere to the culture dish substrate 
C)  chemoattractants require heating for proper function 
D)  actin is present in the structure in each of the 4 photomicrographs 
A)  netrin is acting as a chemoattractant 
B)  filopodia are able to adhere to the culture dish substrate 
C)  chemoattractants require heating for proper function 
D)  actin is present in the structure in each of the 4 photomicrographs

Question 8

The cell type in development that goes on to form melanocytes, bone cells in the skull, and cranial nerves are the _____________________ cells.

Accepted Answer

The answer of The cell type in development that goes...

Question 9

Sensory neurons develops from the ________________ section of the neural tube.

Accepted Answer

A)  rostral 
B)  caudal 
C)  dorsal 
D)  ventral 
A)  rostral 
B)  caudal 
C)  dorsal 
D)  ventral

Question 10

Excessive alcohol exposure is harmful at all ages, but particularly during development. How is it that alcohol produces such deleterious effect at early ages?

Accepted Answer

A)  It may impair neurogenesis 
B)  It may impair neuronal migration 
C)  It may lead to abnormally high rates of neuronal death 
D)  all of the above 
A)  It may impair neurogenesis 
B)  It may impair neuronal migration 
C)  It may lead to abnormally high rates of neuronal death 
D)  all of the above

Question 11

The lab technique that uses labeled probes to visualize RNA transcripts is known as _______________________.

Accepted Answer

in-situ hy

Question 12

Based on the description of chordin's and BMP's functions in the text, what might you expect to happen if chordin was injected into a site away from the dorsal blastopore lip?

Accepted Answer

A)  there would be two sites that begin to differentiate into neural tissue 
B)  the site of injection would develop into neural tissue rather than the dorsal blastopore lip 
C)  the dorsal blastopore lip would develop into skin tissue rather than neural tissue 
D)  all of the above 
A)  there would be two sites that begin to differentiate into neural tissue 
B)  the site of injection would develop into neural tissue rather than the dorsal blastopore lip 
C)  the dorsal blastopore lip would develop into skin tissue rather than neural tissue 
D)  all of the above

Question 13

Consider figure b4.2. The text describes several duplication events in mammals, and subsequently genes have been "lost" in each cluster. What does this statement mean? Re-write in your own words.

Accepted Answer

This statement means that in the evoluti

Question 14

In-situ hybridization is a lab technique that allows you to visualize

Accepted Answer

A)  which parts of an embryo express a given RNA transcript 
B)  the presence of a certain region of DNA in a cell 
C)  the cells of an embryo that are producing antibodies 
D)  all of the above 
A)  which parts of an embryo express a given RNA transcript 
B)  the presence of a certain region of DNA in a cell 
C)  the cells of an embryo that are producing antibodies 
D)  all of the above

Question 15

Consider Figure 4.11. In the text The thalamus is ____________________ to the midbrain.

Accepted Answer

The answer of Consider Figure 4.11. In the text The...

Question 16

Using in-situ hybridization, you see differences in coloration patterns between cells at the gastrula stage of development. Which of the following conclusions could you draw from this experiment?

Accepted Answer

A)  the cells contain different proteins 
B)  the cells contain different transcription factors 
C)  the cells contain different mRNA transcripts 
D)  the cells contain different regions of DNA 
A)  the cells contain different proteins 
B)  the cells contain different transcription factors 
C)  the cells contain different mRNA transcripts 
D)  the cells contain different regions of DNA

Question 17

Which of the following is true of radial cells?

Accepted Answer

A)  They extend processes from the ventricle to the brain's external surface 
B)  they are capable of cell division 
C)  they are progenitor cells that give rise to neurons 
D)  all of the above 
A)  They extend processes from the ventricle to the brain's external surface 
B)  they are capable of cell division 
C)  they are progenitor cells that give rise to neurons 
D)  all of the above

Question 18

The author states: "the fact that different brain regions develop and mature at different times is an effective compromise that allows organisms to survive outside the womb right after birth yet learn what's needed to be a successful adult.". If some areas of brain development aren't complete until the teenage years or later, what do you think is driving this evolutionary compromise? In other words, what traits might be "essential" for a species that are present before the brain is fully developed?

Accepted Answer

The evolutionary compromise of different

Question 19

Consider figure b4.2. In the text Analyze this figure and select which interpretation below is consistent with the findings.

Accepted Answer

A)  Several genes in fruit flies appear to have duplicated somewhere in their ancestral lineage 
B)  Nematodes express a greater variety of Hox genes than cephalochordates 
C)  Each organism contains at least one of each known Hox gene, though some contain duplicates 
D)  Sea urchins are round; therefore they do not require as many Hox genes to direct development 
A)  Several genes in fruit flies appear to have duplicated somewhere in their ancestral lineage 
B)  Nematodes express a greater variety of Hox genes than cephalochordates 
C)  Each organism contains at least one of each known Hox gene, though some contain duplicates 
D)  Sea urchins are round; therefore they do not require as many Hox genes to direct development

Question 20

The process where progenitor cells stop dividing and become neurons is called _________________.

Accepted Answer

The answer of The process where progenitor cells stop dividing...

Relate the study of embryonic chickens to the discovery of trophic factors.

Choose 4 proteins that are important for nervous system development and organize them into a chart, with the name of the protein in one column, its function in another column, and experimental evidence that supports this function in a third column.

You are a researcher studying neurogenesis. You artificially lower the amount of beta-catenin expressed in neural progenitor cells. Which of the following would be likely to result?

Predict what would happen if a gene necessary for the expression of ephrin was mutated so that it becomes non-functional.

You are a researcher studying development. In an experiment, you examine the proteins present in the two cells that arise from a single fertilized frog egg. You are most likely to find that

A candidate molecule for establishing the dorsal-ventral organization of the early nervous system is

Analyze figure 4.20. In the text What is NOT true regarding the process depicted in these photomicrographs?

The cell type in development that goes on to form melanocytes, bone cells in the skull, and cranial nerves are the _____________________ cells.

Sensory neurons develops from the ________________ section of the neural tube.

Excessive alcohol exposure is harmful at all ages, but particularly during development. How is it that alcohol produces such deleterious effect at early ages?

The lab technique that uses labeled probes to visualize RNA transcripts is known as _______________________.

Based on the description of chordin's and BMP's functions in the text, what might you expect to happen if chordin was injected into a site away from the dorsal blastopore lip?

Consider figure b4.2. The text describes several duplication events in mammals, and subsequently genes have been "lost" in each cluster. What does this statement mean? Re-write in your own words.

In-situ hybridization is a lab technique that allows you to visualize

Consider Figure 4.11. In the text The thalamus is ____________________ to the midbrain.

Using in-situ hybridization, you see differences in coloration patterns between cells at the gastrula stage of development. Which of the following conclusions could you draw from this experiment?

Which of the following is true of radial cells?

Consider figure b4.2. In the text Analyze this figure and select which interpretation below is consistent with the findings.

The process where progenitor cells stop dividing and become neurons is called _________________.

Nervous System Organization

Computing With Neurons

Neuronal Plasticity

Protecting and Maintaining the Adult Nervous System

Sensors I: Remote Sensing

Sensors II: Sensing on Contact

Using Muscles and Glands

Regulating Vital Bodily Functions

Controlling Posture and Locomotion

Localizing Stimuli and Orienting in Space

Identifying Stimuli and Stimulus Objects

Regulating Brain States

Remembering Relationships

Selecting Actions, Pursuing Goals

Being Different From Others

Filters

Exam 4: Developing a Nervous System

Relate the study of embryonic chickens to the discovery of trophic factors.

Choose 4 proteins that are important for nervous system development and organize them into a chart, with the name of the protein in one column, its function in another column, and experimental evidence that supports this function in a third column.

You are a researcher studying neurogenesis. You artificially lower the amount of beta-catenin expressed in neural progenitor cells. Which of the following would be likely to result?

Predict what would happen if a gene necessary for the expression of ephrin was mutated so that it becomes non-functional.

You are a researcher studying development. In an experiment, you examine the proteins present in the two cells that arise from a single fertilized frog egg. You are most likely to find that

A candidate molecule for establishing the dorsal-ventral organization of the early nervous system is

Analyze figure 4.20. In the text What is NOT true regarding the process depicted in these photomicrographs?

The cell type in development that goes on to form melanocytes, bone cells in the skull, and cranial nerves are the _____________________ cells.

Sensory neurons develops from the ________________ section of the neural tube.

Excessive alcohol exposure is harmful at all ages, but particularly during development. How is it that alcohol produces such deleterious effect at early ages?

The lab technique that uses labeled probes to visualize RNA transcripts is known as _______________________.

Based on the description of chordin's and BMP's functions in the text, what might you expect to happen if chordin was injected into a site away from the dorsal blastopore lip?

Consider figure b4.2. The text describes several duplication events in mammals, and subsequently genes have been "lost" in each cluster. What does this statement mean? Re-write in your own words.

In-situ hybridization is a lab technique that allows you to visualize

Consider Figure 4.11. In the text The thalamus is ____________________ to the midbrain.

Using in-situ hybridization, you see differences in coloration patterns between cells at the gastrula stage of development. Which of the following conclusions could you draw from this experiment?

Which of the following is true of radial cells?

Consider figure b4.2. In the text Analyze this figure and select which interpretation below is consistent with the findings.

The process where progenitor cells stop dividing and become neurons is called _________________.

Nervous System Organization

Computing With Neurons

Neuronal Plasticity

Protecting and Maintaining the Adult Nervous System

Sensors I: Remote Sensing

Sensors II: Sensing on Contact

Using Muscles and Glands

Regulating Vital Bodily Functions

Controlling Posture and Locomotion

Localizing Stimuli and Orienting in Space

Identifying Stimuli and Stimulus Objects

Regulating Brain States

Remembering Relationships

Selecting Actions, Pursuing Goals

Being Different From Others

Filters