Question 1

What should Danko do when he is informed that his newborn son has PKU (phenylketonuria)? ​

Accepted Answer

PKU is a genetic disorder that can lead to severe intellectual disability if not properly managed. However, it can be controlled through a low-phenylalanine diet. Therefore, Danko should not panic and instead get guidance from a doctor or nutritionist on how to manage his son's diet.

Question 2

Which best exemplifies the concept of incomplete dominance? ​

Accepted Answer

Incomplete dominance occurs when neither allele is dominant, and the resulting phenotype is a blend or combination of both alleles. In the case of an individual with one allele for obesity and another for thinness, their phenotype (weight) would be a combination of both alleles, resulting in an average weight. This is an example of incomplete dominance. Option A is not an example of incomplete dominance, as baldness and hair length are not traits that can blend. Option B and D do not involve two different alleles, which is necessary for incomplete dominance.

Question 3

If obesity is dominant and designated as "O" and thinness is recessive and designated as "t," how many of the following individuals would likely be obese:  Ginger who is "OO," Mary Ann who is "Ot," Thurston who is "tO," and Gilligan who is "tt"?

Accepted Answer

Ginger (OO), Mary Ann (Ot), and Thurston (tO) all have at least one dominant "O" allele, making them likely to be obese. Gilligan (tt) has two recessive alleles, so he would be thin.

Question 4

Following a prenatal exam, your physician remarks, "It appears as if your fetus has 47 chromosomes." What would be the most likely response to this information?

Accepted Answer

The typical number of chromosomes in a human cell is 46, so a fetus with 47 chromosomes may have Down syndrome, which is caused by an extra chromosome 21.

Question 5

Kirk is heterozygous for cheek dimples but is born with big dimples in both cheeks. Apparently, the allele for cheek dimples is

Accepted Answer

Kirk being heterozygous with big dimples in both cheeks suggests that the allele for cheek dimples is dominant.

Question 6

Joseph is homozygous for normal blood cells. This means that he ​

Accepted Answer

Homozygous means that an individual has two identical alleles for a particular gene. In this case, Joseph is homozygous for normal blood cells, meaning he has two copies of the normal allele. This also means he does not have any recessive alleles for abnormal blood cell production. Option A is not accurate since being an identical twin has nothing to do with being homozygous. Option C is incorrect as having recessive alleles would produce abnormal blood cells. Option D is not true since having normal alleles would not lead to sickle-cell anemia.

Question 7

Janaka's two-year-old daughter is mentally retarded due, in part, to a diet that included fish, bread, and dairy products. The most likely diagnosis for Janaka's daughter is that she has ​

Accepted Answer

The symptoms described suggest Phenylketonuria (PKU), which is a genetic metabolic disorder that prevents the breakdown of the amino acid phenylalanine. If left untreated, it can lead to mental retardation and other neurological problems. PKU can be managed through a restricted diet low in phenylalanine, which includes avoiding foods like fish, bread, and dairy products. None of the other options listed fit the symptoms described.

Question 8

How would you create an individual who will definitely have blue eyes?

Accepted Answer

Blue eyes are a recessive trait, which means that both copies of the gene (on both chromosomes) must be for blue eyes in order for the individual to have blue eyes. This is referred to as being homozygous for blue eyes. Therefore, the best way to create an individual who will definitely have blue eyes is to make sure that they have a pair of homozygous chromosomes for blue eyes.

Question 9

Dr. Fry has just been informed that his son has sickle-cell trait. As a knowledgeable physician, Dr. Fry would realize that his son's body is most likely to experience

Accepted Answer

Sickle-cell trait is a genetic condition where a person inherits one copy of the sickle-cell gene from one parent. This gene causes the red blood cells to become stiff and distorted in shape, which can lead to blockages in the blood vessels and reduce the flow of oxygen to the body's tissues and organs. As a result, people with sickle-cell trait are more susceptible to experiencing serious oxygen deprivation, especially during times of physical exertion or stressful events. Excess levels of body fat, decreased lung capacity, and blindness are not typically associated with sickle-cell trait.

Question 10

If tallness is dominant and designated as "T," and shortness is recessive and designated as "s," who would likely be short?

Accepted Answer

Danny has two recessive alleles for shortness, so he would be short.

Question 11

Because of his accurate knowledge of genetics and disorders, Benson knows that his newborn son has no chance of having ​

Accepted Answer

The answer of Because of his accurate knowledge of genetics...

Question 12

Huntington's disease is an unusual genetic disorder in that it is a fatal disease caused by dominant alleles that ​

Accepted Answer

Huntington's disease is caused by a dominant allele on chromosome 4, meaning that if an individual inherits one copy of the faulty gene from either parent, they will develop the disease. However, symptoms typically do not appear until middle age, after the individual has already had a chance to reproduce. This allows the faulty allele to be passed down through generations before the disease is even detected.

Question 13

Linda has one allele for curly hair and another for straight hair. Linda's alleles are

Accepted Answer

Linda has two different alleles for the same gene, which makes her heterozygous.

Question 14

Which physical characteristic is most indicative of an individual with Down syndrome? ​

Accepted Answer

A fold of skin over each eyelid, known as an epicanthal fold, is a physical characteristic commonly seen in individuals with Down syndrome. It is caused by the way the skin around the eye is formed and does not affect vision. While individuals with Down syndrome may also have other physical characteristics such as a smaller tongue or shorter stature, the most indicative feature is the epicanthal fold.

Question 15

____ is characterized by progressive degeneration of the nervous system.

Accepted Answer

Huntington's disease is a genetic disorder that causes progressive degeneration of nerve cells in the brain, leading to both physical and mental impairments. It is caused by a mutation in the HTT gene, which leads to the accumulation of toxic proteins in the brain. Symptoms usually appear in mid-adulthood and gradually worsen over time, eventually leading to death. There is no cure for Huntington's disease, although some medications can help manage its symptoms.

Question 16

"Trisomy  21" (three 21st chromosomes)best describes ​

Accepted Answer

Trisomy 21 refers to the genetic condition in which an individual has three copies of the 21st chromosome, resulting in Down syndrome. Huntington's disease is caused by a mutation in the huntingtin gene, not a trisomy of a specific chromosome. Phenylketonuria (PKU) is an inherited disorder caused by a deficiency of the enzyme needed to process the amino acid phenylalanine. Sickle-cell trait is caused by a mutation in the beta-globin gene on chromosome 11, not a trisomy of a specific chromosome.

Question 17

Which combination of sex chromosomes is not possible in a living human being?

Accepted Answer

A single Y chromosome cannot result in a living human being as it contains vital genetic information which is necessary for development and survival.

Question 18

If a person had a dominant allele for blonde hair and a recessive allele for red hair, the probability of that person having red hair would be closest to ____ percent. ​

Accepted Answer

A dominant allele will mask the expression of a recessive allele, so the person will have blonde hair, not red.

Question 19

Which maternal characteristic is most strongly associated with giving birth to a baby with Down syndrome?

Accepted Answer

The strongest maternal characteristic associated with giving birth to a baby with Down syndrome is higher maternal age, particularly for women over the age of 35. This is because as women age, the likelihood of errors during meiosis increases, resulting in an extra copy of chromosome 21 in the egg cell, which leads to Down syndrome. Low levels of intelligence, alcohol consumption, and exposure to lead or mercury have not been found to have a significant association with an increased risk of giving birth to a baby with Down syndrome.

Question 20

Which statement concerning the sickle-cell trait is true?

Accepted Answer

The sickle-cell trait is caused by having one copy of the mutated hemoglobin gene and one copy of the normal hemoglobin gene. Therefore, individuals with the trait have both a dominant and recessive allele for the disorder. However, because the normal hemoglobin gene is dominant, individuals with the trait do not display symptoms of sickle-cell anemia.

Quiz 2: Biological Foundations: Heredity, Prenatal Development, and Birth

What should Danko do when he is informed that his newborn son has PKU (phenylketonuria) ?

Which best exemplifies the concept of incomplete dominance?

If obesity is dominant and designated as "O" and thinness is recessive and designated as "t," how many of the following individuals would likely be obese: Ginger who is "OO," Mary Ann who is "Ot," Thurston who is "tO," and Gilligan who is "tt"?

Following a prenatal exam, your physician remarks, "It appears as if your fetus has 47 chromosomes." What would be the most likely response to this information?

Kirk is heterozygous for cheek dimples but is born with big dimples in both cheeks. Apparently, the allele for cheek dimples is

Joseph is homozygous for normal blood cells. This means that he

Janaka's two-year-old daughter is mentally retarded due, in part, to a diet that included fish, bread, and dairy products. The most likely diagnosis for Janaka's daughter is that she has

How would you create an individual who will definitely have blue eyes?

Dr. Fry has just been informed that his son has sickle-cell trait. As a knowledgeable physician, Dr. Fry would realize that his son's body is most likely to experience

If tallness is dominant and designated as "T," and shortness is recessive and designated as "s," who would likely be short?

Because of his accurate knowledge of genetics and disorders, Benson knows that his newborn son has no chance of having

Huntington's disease is an unusual genetic disorder in that it is a fatal disease caused by dominant alleles that

Linda has one allele for curly hair and another for straight hair. Linda's alleles are

Which physical characteristic is most indicative of an individual with Down syndrome?

____ is characterized by progressive degeneration of the nervous system.

"Trisomy 21" (three 21st chromosomes) best describes

Which combination of sex chromosomes is not possible in a living human being?

If a person had a dominant allele for blonde hair and a recessive allele for red hair, the probability of that person having red hair would be closest to ____ percent.

Which maternal characteristic is most strongly associated with giving birth to a baby with Down syndrome?

Which statement concerning the sickle-cell trait is true?

Quiz 2: Biological Foundations: Heredity, Prenatal Development, and Birth

What should Danko do when he is informed that his newborn son has PKU (phenylketonuria) ? ​

Which best exemplifies the concept of incomplete dominance? ​

If obesity is dominant and designated as "O" and thinness is recessive and designated as "t," how many of the following individuals would likely be obese: Ginger who is "OO," Mary Ann who is "Ot," Thurston who is "tO," and Gilligan who is "tt"?

Following a prenatal exam, your physician remarks, "It appears as if your fetus has 47 chromosomes." What would be the most likely response to this information?

Kirk is heterozygous for cheek dimples but is born with big dimples in both cheeks. Apparently, the allele for cheek dimples is

Joseph is homozygous for normal blood cells. This means that he ​

Janaka's two-year-old daughter is mentally retarded due, in part, to a diet that included fish, bread, and dairy products. The most likely diagnosis for Janaka's daughter is that she has ​

How would you create an individual who will definitely have blue eyes?

Dr. Fry has just been informed that his son has sickle-cell trait. As a knowledgeable physician, Dr. Fry would realize that his son's body is most likely to experience

If tallness is dominant and designated as "T," and shortness is recessive and designated as "s," who would likely be short?

Because of his accurate knowledge of genetics and disorders, Benson knows that his newborn son has no chance of having ​

Huntington's disease is an unusual genetic disorder in that it is a fatal disease caused by dominant alleles that ​

Linda has one allele for curly hair and another for straight hair. Linda's alleles are

Which physical characteristic is most indicative of an individual with Down syndrome? ​

____ is characterized by progressive degeneration of the nervous system.

"Trisomy 21" (three 21st chromosomes) best describes ​

Which combination of sex chromosomes is not possible in a living human being?

If a person had a dominant allele for blonde hair and a recessive allele for red hair, the probability of that person having red hair would be closest to ____ percent. ​

Which maternal characteristic is most strongly associated with giving birth to a baby with Down syndrome?

Which statement concerning the sickle-cell trait is true?

What should Danko do when he is informed that his newborn son has PKU (phenylketonuria) ?

Which best exemplifies the concept of incomplete dominance?

Joseph is homozygous for normal blood cells. This means that he

Janaka's two-year-old daughter is mentally retarded due, in part, to a diet that included fish, bread, and dairy products. The most likely diagnosis for Janaka's daughter is that she has

Because of his accurate knowledge of genetics and disorders, Benson knows that his newborn son has no chance of having

Huntington's disease is an unusual genetic disorder in that it is a fatal disease caused by dominant alleles that

Which physical characteristic is most indicative of an individual with Down syndrome?

"Trisomy 21" (three 21st chromosomes) best describes

If a person had a dominant allele for blonde hair and a recessive allele for red hair, the probability of that person having red hair would be closest to ____ percent.