Question 1

Enzymes serve as ____.​

Accepted Answer

Enzymes are biological catalysts that speed up chemical reactions in the body by lowering the activation energy required for the reaction to occur. They do not serve as genetic templates, physiological markers, or catalysts for the synthesis of protein molecules.

Question 2

What is one impediment to the regeneration of axons in the mammalian central nervous system?​

Accepted Answer

One of the major impediments to axon regeneration in the mammalian central nervous system is the release of inhibitory chemicals by glial cells. These chemicals act as a roadblock for axons trying to regrow and reestablish connections with other neurons.

Question 3

Suppose "A" is a dominant gene for the ability to taste phenylthiocarbamide and "a" is a recessive gene for the inability to taste it.Which couples could possibly have both a child who tastes it and a child who does not?​

Accepted Answer

When both parents are heterozygous (Aa), there is a chance that each of their offspring will inherit either an A or an a gene from each parent. This means that some of their children may be AA (able to taste PTC), some may be Aa (able to taste PTC but carry the recessive gene), and some may be aa (unable to taste PTC). Therefore, it is possible for this couple to have both a child who tastes PTC (AA or Aa) and a child who does not (aa).

Question 4

After damage to a set of axons,neurotrophins induce nearby ____.​

Accepted Answer

Neurotrophins, which are a family of proteins that induce the survival, development, and function of neurons, can stimulate nearby uninjured axons to form new branches after a set of axons has been damaged. This process helps in neural regeneration and the reestablishment of neural connections.

Question 5

Chemically,what is the route from genes to their expression?​

Accepted Answer

The central dogma of molecular biology describes the process by which information flows from genes, to RNA, to proteins. DNA is transcribed into RNA, which is then translated into proteins. This means that genes are translated into their protein products through an RNA intermediate, making choice B the correct answer.

Question 6

After learning strengthens one set of synapses,other synapses ____.​

Accepted Answer

After learning strengthens one set of synapses, other synapses weaken. This is because synaptic plasticity is a mechanism for learning and memory in the brain where the strengthening of some synapses is accompanied by the weakening of others. This is known as synaptic competition, where synapses compete with each other for resources and influence on the post-synaptic neuron. Therefore, the correct answer is A, other synapses weaken.

Question 7

A continuing sensation of an amputated body part is called ____.​

Accepted Answer

The term "phantom limb" specifically refers to the continuing sensation of an amputated body part, while "ghost limb" is not a commonly used term in medical or scientific literature. "Neuralgia" refers to pain caused by nerve damage or irritation, while "tingling limb" is a general sensation that could be caused by a variety of factors.

Question 8

One way to relieve the pain associated with a phantom limb is to ____.​

Accepted Answer

The answer of One way to relieve the pain associated...

Question 9

If some of the axons innervating a given cell are destroyed or if they become inactive,what compensatory process takes place in the remaining presynaptic cells?​

Accepted Answer

When some axons innervating a given cell are destroyed or become inactive, a compensatory process called collateral sprouting takes place in the remaining presynaptic cells. Collateral sprouting is the growth of new branches from intact axons to form new synapses with the postsynaptic cell. This can help to restore lost connections and maintain neuronal function.

Question 10

The results of several studies of facial expressions in people who were born blind suggest ____.​

Accepted Answer

Studies on individuals who were born blind show that they exhibit facial expressions similar to those of sighted individuals, even in the absence of visual learning from observing others. This suggests that genetics plays a significant role in the development and control of facial expressions, alongside environmental factors.

Question 11

A person with two recessive genes is considered to be ____ for that trait.​

Accepted Answer

Homozygous means that an individual has two identical alleles for a particular trait. In this case, the person has two recessive alleles, which means they are homozygous recessive for that trait.

Question 12

A cortical cell originally responded to stimulation of the middle finger.After amputation of that finger,it begins responding to the second and fourth fingers.Which action most likely accounts for this?​

Accepted Answer

Synaptic reorganization refers to the rewiring of neural connections in response to changes in input or injury. In this case, the cortical cell's connections have been rewired to respond to sensory input from nearby fingers after the middle finger was amputated. This type of adaptation is a well-documented phenomenon in the brain. Growth of completely new axons is unlikely to occur as it would require the development of entirely new neural pathways, which is not a common occurrence in adulthood. Alterations to blood vessel patterns in the brain would not affect the function of individual cortical cells. The response is not indicative of a psychotic reaction.

Question 13

Diaschisis refers to the ____.​

Accepted Answer

Diaschisis refers to the reduced activity of surviving neurons after other neurons are damaged. This can occur remotely from the damaged area and is thought to be due to disrupted connections between neurons.

Question 14

Chromosomes consist of large,double-stranded molecules of ____.​

Accepted Answer

Chromosomes consist of large, double-stranded molecules of deoxyribonucleic acid (DNA). DNA is the genetic material that contains the instructions for the development and function of all living organisms. RNA, on the other hand, is a single-stranded molecule that plays various roles in gene expression, but is not the main component of chromosomes. Autosomal and recombination genes are specific types of genes found on chromosomes, but they are not the main components of the chromosomes themselves.

Question 15

Which treatment would be most likely to help a patient starting it several days after a stroke?​

Accepted Answer

Giving stimulant drugs combined with physical therapy would be the best option to help a patient starting several days after a stroke. This is because stimulant drugs can help to improve brain function and physical therapy can aid in the recovery of motor skills. Tranquilizers and bed rest would not be beneficial for stroke recovery, and the use of drugs to block dopamine is not a common treatment for stroke.

Question 16

Heightened sensitivity to a neurotransmitter after the destruction of an incoming axon is known as ____.​

Accepted Answer

Denervation supersensitivity refers to an increase in sensitivity to a neurotransmitter after the destruction of an incoming axon. This occurs because the receiving neurons become more responsive to the remaining neurotransmitter released by other axons. None of the other options are correct descriptions of this phenomenon.

Question 17

Units of heredity that maintain their structural identity from one generation to another are known as ____.​

Accepted Answer

Genes are the units of heredity that maintain their structural identity from one generation to another. Enzymes are biological catalysts that speed up chemical reactions, mutations are changes in genetic material, and nucleic acids are the macromolecules that encode genetic information.

Question 18

A strand of DNA serves as a template (model)for the synthesis of ____.​

Accepted Answer

DNA serves as a template for RNA synthesis through the process of transcription. RNA, in turn, can serve as a template for protein synthesis through the process of translation. Chromosomes are structures made up of DNA, while carbohydrates are not synthesized using DNA templates.

Question 19

A trait not expressed when combined with a dominant trait is called a(n)____ trait.​

Accepted Answer

A recessive trait is not expressed when combined with a dominant trait because the dominant trait masks it.

Question 20

If most of the axons that transmit dopamine to some brain area die or become inactive,the remaining dopamine synapses become ____.​

Accepted Answer

If most of the axons that transmit dopamine to some brain area die or become inactive, the remaining dopamine synapses will need to work harder to compensate for the loss. This can lead to increased responsiveness or sensitivity to dopamine. Therefore, the best choice is D - more responsive.

Quiz 4: Genetics, evolution, development, and Plasticity

Enzymes serve as ____.

What is one impediment to the regeneration of axons in the mammalian central nervous system?

Suppose "A" is a dominant gene for the ability to taste phenylthiocarbamide and "a" is a recessive gene for the inability to taste it.Which couples could possibly have both a child who tastes it and a child who does not?

After damage to a set of axons,neurotrophins induce nearby ____.

Chemically,what is the route from genes to their expression?

After learning strengthens one set of synapses,other synapses ____.

A continuing sensation of an amputated body part is called ____.

One way to relieve the pain associated with a phantom limb is to ____.

If some of the axons innervating a given cell are destroyed or if they become inactive,what compensatory process takes place in the remaining presynaptic cells?

The results of several studies of facial expressions in people who were born blind suggest ____.

A person with two recessive genes is considered to be ____ for that trait.

A cortical cell originally responded to stimulation of the middle finger.After amputation of that finger,it begins responding to the second and fourth fingers.Which action most likely accounts for this?

Diaschisis refers to the ____.

Chromosomes consist of large,double-stranded molecules of ____.

Which treatment would be most likely to help a patient starting it several days after a stroke?

Heightened sensitivity to a neurotransmitter after the destruction of an incoming axon is known as ____.

Units of heredity that maintain their structural identity from one generation to another are known as ____.

A strand of DNA serves as a template (model) for the synthesis of ____.

A trait not expressed when combined with a dominant trait is called a(n) ____ trait.

If most of the axons that transmit dopamine to some brain area die or become inactive,the remaining dopamine synapses become ____.