Question 1

One out of 800 babies are born with an extra chromosome at pair 21, which results in the child having a moderate to severe intellectual disability and a shortened life expectancy of around 49 years. This condition is known as

Accepted Answer

Down syndrome is caused by an extra chromosome at pair 21, leading to the characteristics described, including intellectual disability and a shortened life expectancy.

Question 2

Regarding Down syndrome, which of the following statements is FALSE?

Accepted Answer

Down syndrome is not considered a hereditary condition in the traditional sense, as it does not tend to run in families. Most cases are caused by a random error in cell division that results in an extra 21st chromosome (trisomy 21).

Question 3

Aaron is seven years old, is larger than average for his age, and has a long, thin face and big ears. He has an intellectual disability, is hyperactive, and has a peculiar tendency to avoid eye contact with others. Aaron most likely has

Accepted Answer

Aaron's symptoms, including a long, thin face, big ears, intellectual disability, hyperactivity, and avoidance of eye contact, are characteristic of fragile X syndrome, a genetic condition that causes a range of developmental problems.

Question 4

Which hereditary cause of intellectual disability affects male children at a rate of about 1 out of every 5000 males with up to three-fourths of individuals with this disorder having hyperactivity and attention disorders?

Accepted Answer

Fragile X syndrome is a genetic disorder that causes intellectual disability, behavioral and learning challenges, and is the most common inherited cause of intellectual disability. It affects males more severely than females due to its inheritance pattern related to the X chromosome. Hyperactivity and attention disorders are common in individuals with fragile X syndrome.

Question 5

Regarding phenylketonuria (PKU), which of the following statements is TRUE?

Accepted Answer

PKU is caused by a deficiency in the enzyme phenylalanine hydroxylase, which is necessary for the conversion of phenylalanine to tyrosine. Tyrosine is a precursor for dopamine, so low levels of tyrosine can lead to low levels of dopamine.

Question 6

As people age, their reproductive cells are more prone to errors during cell division. This raises the odds that an extra chromosome will be present and result in the most common form of genetic intellectual disability known as

Accepted Answer

Down syndrome is caused by an extra copy of chromosome 21 (trisomy 21), which can occur more frequently in the offspring of older parents due to errors in cell division leading to nondisjunction.

Question 7

Which of the following is the second most common form of genetic intellectual disability and affects more males than females?

Accepted Answer

Fragile X syndrome is the second most common form of genetic intellectual disability after Down syndrome and affects more males than females due to its inheritance pattern related to the X chromosome.

Question 8

The age of the mother and father is a significant factor in the child being born with which condition?

Accepted Answer

The age of the mother, particularly advanced maternal age, is a significant factor in the risk of a child being born with Down syndrome due to the increased likelihood of chromosomal abnormalities such as trisomy 21.

Question 9

Pete is an adult with an intellectual disability, which has become more severe than it was when he was a young child. Physically, he has a thin face, large ears, and appears smaller than average, although he was larger than average as a child. Regarding his adaptive behaviors, his daily living skills are better than his language and social skills. Pete most likely has the hereditary condition known as

Accepted Answer

Pete's symptoms, including a thin face, large ears, smaller physical stature in adulthood compared to larger size in childhood, and the pattern of adaptive behaviors where daily living skills are relatively better preserved than language and social skills, are characteristic of fragile X syndrome. This condition is a genetic disorder that often shows these physical and behavioral signs.

Question 10

Regarding Down syndrome, which of the following statements is FALSE?

Accepted Answer

Down syndrome is caused by an extra copy of chromosome 21 (trisomy 21), not by abnormalities in the X chromosome. This is a fundamental aspect of its genetic basis, distinguishing it from conditions linked to the sex chromosomes.

Question 11

Which of the following is a genetic disease that can be detected in newborn babies by routine medical testing with the resulting intellectual disability being prevented by placing the child on a diet low in a substance the child's body can't handle?

Accepted Answer

Phenylketonuria (PKU) is a genetic disorder that can be detected in newborns through routine medical testing. Affected individuals have a deficiency in the enzyme needed to process the amino acid phenylalanine. A diet low in phenylalanine can prevent the intellectual disabilities associated with PKU.

Question 12

Regarding Down syndrome, which of the following statements is TRUE?

Accepted Answer

Down syndrome is caused by the presence of an extra chromosome 21, making it a trisomy 21 condition. This is not inherited in the traditional sense, nor is it related to lifestyle choices or chemical imbalances.

Question 13

Mae, who has a mild intellectual disability, can do most of the things that other children can, only slower. She has almond-shaped eyes, a slightly protruding tongue, a stocky build, and stubby hands with deeply creased palms. Mae most likely has which condition?

Accepted Answer

Mae's described physical characteristics, such as almond-shaped eyes, a slightly protruding tongue, stocky build, and stubby hands with deeply creased palms, are common indicators of Down syndrome. Additionally, individuals with Down syndrome can often do most things that other children can, albeit at a slower pace, which matches the description provided.

Question 14

The best hope for children with Down syndrome would involve

Accepted Answer

Down syndrome is a genetic condition and cannot be cured by dietary changes or surgical interventions aimed at conditions like phenylalanine restriction (which is for PKU) or fluid drainage (for hydrocephalus). A specially tailored educational program can help children with Down syndrome develop to their fullest potential, addressing their specific learning needs and abilities.

Question 15

Children who have phenylketonuria (PKU)lack an important enzyme, which causes which of the following to collect within their bodies?

Accepted Answer

Children with phenylketonuria (PKU) lack the enzyme phenylalanine hydroxylase, which is necessary for converting phenylalanine into tyrosine. As a result, phenylalanine accumulates in the body and is converted into phenylpyruvic acid, which can cause brain damage and other serious problems if not treated.

Question 16

Regarding Down syndrome, which of the following statements is FALSE?

Accepted Answer

Down syndrome occurs with equal frequency in males and females; there is no increased prevalence in one gender over the other.

Question 17

Down syndrome results from flaws in the parents' egg or sperm cells, a condition called

Accepted Answer

Down syndrome is characterized by an extra copy of chromosome 21, a condition known as trisomy-21, which results from errors in the division of the parents' egg or sperm cells.

Question 18

At birth, Sam was found to have a genetically induced lack of an enzyme. He is placed on a diet, which includes not eating any foods containing the artificial sweetener aspartame. This diet will help prevent the development of an intellectual disability. Sam most likely has which condition?

Accepted Answer

Phenylketonuria (PKU) is a genetic disorder caused by a deficiency in the enzyme phenylalanine hydroxylase, which is necessary for the metabolism of the amino acid phenylalanine. Aspartame contains phenylalanine, so individuals with PKU must avoid it to prevent the accumulation of phenylalanine, which can lead to intellectual disability and other health issues if not managed through diet.

Question 19

Fragile X syndrome occurs because the person has

Accepted Answer

Fragile X syndrome is caused by a genetic mutation where there is a fragile site on the X chromosome, specifically an expansion of the CGG trinucleotide repeat affecting the FMR1 gene. This does not involve an extra X chromosome, a missing X chromosome, or an X chromosome in an abnormal location.

Question 20

Regarding fragile X syndrome, which of the following statements is TRUE?

Accepted Answer

Fragile X syndrome is indeed a sex-linked (specifically X-linked) hereditary condition caused by a mutation in the FMR1 gene on the X chromosome, leading to a range of developmental problems including learning disabilities and cognitive impairment. It does not involve an enzyme deficiency, an extra chromosome, or a thyroid hormone insufficiency.

Quiz 9: Intelligence

One out of 800 babies are born with an extra chromosome at pair 21, which results in the child having a moderate to severe intellectual disability and a shortened life expectancy of around 49 years. This condition is known as

Regarding Down syndrome, which of the following statements is FALSE?

Aaron is seven years old, is larger than average for his age, and has a long, thin face and big ears. He has an intellectual disability, is hyperactive, and has a peculiar tendency to avoid eye contact with others. Aaron most likely has

Which hereditary cause of intellectual disability affects male children at a rate of about 1 out of every 5000 males with up to three-fourths of individuals with this disorder having hyperactivity and attention disorders?

Regarding phenylketonuria (PKU) , which of the following statements is TRUE?

As people age, their reproductive cells are more prone to errors during cell division. This raises the odds that an extra chromosome will be present and result in the most common form of genetic intellectual disability known as

Which of the following is the second most common form of genetic intellectual disability and affects more males than females?

The age of the mother and father is a significant factor in the child being born with which condition?

Regarding Down syndrome, which of the following statements is FALSE?

Which of the following is a genetic disease that can be detected in newborn babies by routine medical testing with the resulting intellectual disability being prevented by placing the child on a diet low in a substance the child's body can't handle?

Regarding Down syndrome, which of the following statements is TRUE?

Mae, who has a mild intellectual disability, can do most of the things that other children can, only slower. She has almond-shaped eyes, a slightly protruding tongue, a stocky build, and stubby hands with deeply creased palms. Mae most likely has which condition?

The best hope for children with Down syndrome would involve

Children who have phenylketonuria (PKU) lack an important enzyme, which causes which of the following to collect within their bodies?

Regarding Down syndrome, which of the following statements is FALSE?

Down syndrome results from flaws in the parents' egg or sperm cells, a condition called

At birth, Sam was found to have a genetically induced lack of an enzyme. He is placed on a diet, which includes not eating any foods containing the artificial sweetener aspartame. This diet will help prevent the development of an intellectual disability. Sam most likely has which condition?

Fragile X syndrome occurs because the person has

Regarding fragile X syndrome, which of the following statements is TRUE?