Question 1

What is a "Hebb synapse," and how does this concept help us understand the segregation between input from each eye in the lateral geniculate nucleus of the adult animal?

Accepted Answer

Hebb is the scientist who first postulat...

Question 2

About two-thirds of the cells traveling to the developing cortex follow radial glia, and the remaining one-third move in a horizontal direction instead, without using radial glia to guide them.

Accepted Answer

A) True 
 B)False

Question 3

At the peak of neurogenesis in humans, about how many new neural cells are produced per minute?

Accepted Answer

A)   10,000
B)   75,000
C)   250,000
D)   500,000

Question 4

How many chromosomes do human beings receive from each parent?

Accepted Answer

A)   23
B)   46
C)   21
D)   42

Question 5

The leading known nongenetic cause of intellectual disability is

Accepted Answer

A)   alcohol use by pregnant women.
B)   marijuana use by the partner of a pregnant woman.
C)   prenatal exposure to lead-based paints.
D)   environmental asbestos exposure during pregnancy.

Question 6

Nancy and Cliff had four children who did not have cystic fibrosis, but their fifth child was born with the disease. Cystic fibrosis is carried on a recessive gene. Given what you've learned in this chapter, how could this happen?

Accepted Answer

A)   It wasn't until the fifth child that both parents passed on the allele for this illness.
B)   Recessive genes normally skip a generation, but after the parents had five children, the gene was expressed.
C)   Their fifth child must have been a boy, which makes it more probable that he would have the illness.
D)   Their fifth child must have been a girl, which makes it more probable that she would have the illness.

Question 7

Gene expression refers to the

Accepted Answer

A)   division of the chromosomes in half during the formation of eggs and sperm.
B)   passing along of genes that are located close to one another on a chromosome.
C)   conversion of genetic instructions into a feature of a living cell.
D)   imprinting of particular genes.

Question 8

The human genome contains about ________ protein-building genes.

Accepted Answer

A)   9,500
B)   19,000
C)   100,000
D)   2.5 million

Question 9

It is ______ that protect(s)  a cell from apoptosis.

Accepted Answer

A)   cell adhesion molecules
B)   inducing protein
C)   neurotrophins
D)   sonic hedgehog

Question 10

Brain weight begins to decline significantly in humans past the age of _________ years.

Accepted Answer

A)   20
B)   45
C)   65
D)   80

Question 11

In which of the following conditions can the failure to follow a carefully prescribed diet result in intellectual disability?

Accepted Answer

A)   Williams syndrome
B)   Alzheimer's disease
C)   Fragile-X syndrome
D)   PKU

Question 12

How many chromosomes are typically present in human cells?

Accepted Answer

A)   20 pairs for a total of 40 chromosomes
B)   21 pairs for a total of 42 chromosomes
C)   22 pairs for a total of 44 chromosomes
D)   23 pairs for a total of 46 chromosomes

Question 13

Tom's father has hemophilia, but Tom does not have the disease. What are the chances that Tom's children will have hemophilia?

Accepted Answer

A)   Tom's sons will almost certainly have it because Tom will have inherited the recessive gene from this father.
B)   Tom's daughters may be carriers, but his sons will not have the gene.
C)   All of Tom's children will be carriers, but it will not be expressed until they have children.
D)   None of Tom's children will be carriers or have the illness because his X gene came from his mother, who is not a carrier.

Question 14

Which of the following substances appears to enhance adult neurogenesis in rats?

Accepted Answer

A)   antidepressant medications
B)   sonic hedgehog
C)   alcohol
D)   marijuana

Question 15

Extreme skewing in x-inactivation has been linked with which of the following characteristics in offspring?

Accepted Answer

A)   hemophilia
B)   colorblindness
C)   Alzheimer's disease
D)   autoimmune diseases

Question 16

The interior of the neural tube will be retained in the adult brain as the

Accepted Answer

A)   forebrain.
B)   ventricles and central canal of the spinal cord.
C)   hindbrain.
D)   corpus callosum.

Question 17

Neurogenesis is now known to occur throughout life, though at different rates. Describe possible benefits of adult neurogenesis.

Accepted Answer

While neurogenesis in adulthoo...

Question 18

In human development, this layer develops into most of the internal organs.

Accepted Answer

A)   the endoderm
B)   the mesoderm
C)   the ectoderm
D)   the blastoderm

Question 19

Apoptosis occurs when cell death genes are activated and ______ are expressed.

Accepted Answer

A)   apoptotic
B)   blastocyst
C)   caspases
D)   degradation

Question 20

Completion of myelination in the CNS is one possible reason that

Accepted Answer

A)   does not have observable behavioral effects, as the process is completed before birth in humans.
B)   might account for the ability of children to learn to read and write.
C)   coincides with the onset of puberty and children's ability to think in abstract terms.
D)   might account for superior decision making in adults compared to teens.

Exam 5: Genetics and the Development of the Human Brain

The interior of the neural tube will be retained in the adult brain as the

Correct AnswerverifiedShow Answer

Apoptosis occurs when cell death genes are activated and ______ are expressed.

Correct AnswerverifiedShow Answer

Completion of myelination in the CNS is one possible reason that

Correct AnswerverifiedShow Answer

Brain weight begins to decline significantly in humans past the age of _________ years.

Correct AnswerverifiedShow Answer

Gene expression refers to the

Correct AnswerverifiedShow Answer

Which of the following substances appears to enhance adult neurogenesis in rats?

Correct AnswerverifiedShow Answer

In human development, this layer develops into most of the internal organs.

Correct AnswerverifiedShow Answer

The human genome contains about ________ protein-building genes.

Correct AnswerverifiedShow Answer

In which of the following conditions can the failure to follow a carefully prescribed diet result in intellectual disability?

Correct AnswerverifiedShow Answer

Tom's father has hemophilia, but Tom does not have the disease. What are the chances that Tom's children will have hemophilia?

Correct AnswerverifiedShow Answer

Extreme skewing in x-inactivation has been linked with which of the following characteristics in offspring?

Correct AnswerverifiedShow Answer

The leading known nongenetic cause of intellectual disability is

Correct AnswerverifiedShow Answer

About two-thirds of the cells traveling to the developing cortex follow radial glia, and the remaining one-third move in a horizontal direction instead, without using radial glia to guide them.

Correct AnswerverifiedShow Answer

Neurogenesis is now known to occur throughout life, though at different rates. Describe possible benefits of adult neurogenesis.

Correct AnswerverifiedWhile neurogenesis in adulthoo...View AnswerShow Answer

What is a "Hebb synapse," and how does this concept help us understand the segregation between input from each eye in the lateral geniculate nucleus of the adult animal?

Correct AnswerverifiedHebb is the scientist who first postulat...View AnswerShow Answer

How many chromosomes are typically present in human cells?

Correct AnswerverifiedShow Answer

At the peak of neurogenesis in humans, about how many new neural cells are produced per minute?

Correct AnswerverifiedShow Answer

Nancy and Cliff had four children who did not have cystic fibrosis, but their fifth child was born with the disease. Cystic fibrosis is carried on a recessive gene. Given what you've learned in this chapter, how could this happen?

Correct AnswerverifiedShow Answer

It is ______ that protect(s) a cell from apoptosis.

Correct AnswerverifiedShow Answer

How many chromosomes do human beings receive from each parent?

Correct AnswerverifiedShow Answer

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While neurogenesis in adulthoo...
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Hebb is the scientist who first postulat...
View Answer

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