Question 1

The most common type of inherited intellectual disability is ________.

Accepted Answer

Fragile X syndrome is the most common inherited intellectual disability, affecting about 1 in 4,000 males and 1 in 8,000 females. It occurs when there is a mutation in the X chromosome that affects the production of a protein necessary for brain development. This results in intellectual disability, along with other symptoms such as developmental delays, behavior problems, and physical features like a long face and large ears.

Question 2

Klinefelter's syndrome is characterized by a ________ chromosomal makeup.

Accepted Answer

Klinefelter's syndrome occurs when a male has an extra X chromosome, resulting in a chromosomal makeup of XXY. This can lead to various physical and developmental symptoms, such as infertility, low testosterone levels, and breast development.

Question 3

About 1 in ________ French Canadians in Eastern Quebec is a carrier of the recessive gene responsible for Tay-Sachs disease.

Accepted Answer

Tay-Sachs disease is a rare genetic disorder that affects about 1 in 3,600 births in the Ashkenazi Jewish population and 1 in 30,000 births in the general population. However, in Eastern Quebec, an estimated 1 in 14 individuals of French Canadian ancestry is a carrier of the Tay-Sachs allele. Therefore, the best choice is C, 14.

Question 4

Klinefelter's syndrome involves an extra ________.

Accepted Answer

Klinefelter's syndrome is caused by the presence of an extra X chromosome in males, resulting in a genotype of XXY instead of the typical XY.

Question 5

Phenylketonuria is found in 1 person in ________.

Accepted Answer

Phenylketonuria (PKU) is a rare inherited disorder that affects about 1 in 10,000 births in the United States, indicating its prevalence is approximately 1 in 10,000 people.

Question 6

Most people with Down syndrome tend to die ________.

Accepted Answer

Most individuals with Down syndrome tend to live into middle age, with many reaching their 50s and beyond, thanks to advances in medical care and improved living conditions.

Question 7

Fragile X syndrome causes intellectual disability in 1 of every ________ males.

Accepted Answer

Fragile X syndrome causes intellectual disability in 1 out of every 1000 to 1500 males.

Question 8

Fragile X syndrome causes mental handicaps in 1 of every ________ females.

Accepted Answer

The answer of Fragile X syndrome causes mental handicaps in...

Question 9

A genetic abnormality transmitted by a recessive gene that prevents an infant from metabolizing an amino acid found in many foods,resulting in intellectual disability and emotional disturbance,is ________.

Accepted Answer

Phenylketonuria (PKU) is a genetic disorder that involves a malfunctioning enzyme that prevents the metabolism of phenylalanine, an amino acid found in many foods. This results in the buildup of phenylalanine in the blood and brain, causing intellectual disability and emotional disturbance if left untreated. PKU is transmitted by a recessive gene, meaning that both parents must carry the gene for their child to be affected. Klinefelter's syndrome and Turner's syndrome are genetic disorders that involve sex chromosome abnormalities, while Tay-Sachs disease is a genetic disorder that involves the accumulation of a specific type of fatty substance in the brain and nervous system.

Question 10

Phenylketonuria is caused by ________.

Accepted Answer

Phenylketonuria is caused by a recessive gene. A person must inherit two copies of the mutated gene (one from each parent) in order to have the condition.

Question 11

Tay-Sachs disease is caused by ________.

Accepted Answer

The answer of Tay-Sachs disease is caused by ________.
...

Question 12

Denzel never developed appropriate male secondary sexual characteristics.Fellow male classmates often tease him because of his enlarged breasts and his poor muscular coordination.He also has mild intellectual disability and is infertile.Denzel is most likely suffering from ________.

Accepted Answer

Denzel's symptoms are characteristic of Klinefelter's syndrome, a genetic disorder in which males have an extra X chromosome (XXY instead of XY). This leads to underdeveloped testes, resulting in reduced testosterone levels and the development of female secondary sexual characteristics such as breast enlargement. It can also lead to cognitive and learning difficulties, as well as infertility. The other options listed (Turner's syndrome, phenylketonuria, and Tay-Sachs disease) are not consistent with Denzel's symptoms.

Question 13

The second leading cause of intellectual disability is ________.

Accepted Answer

Fragile X syndrome is the second leading cause of intellectual disability after Down syndrome. It is a genetic condition that affects the X chromosome and is more commonly found in males than females. Symptoms may include developmental delays, social and behavioral problems, and physical features such as a long face and large ears.

Question 14

A fatal degenerative disease caused by recessive genes that causes gradual loss of muscle control,deafness,blindness,intellectual disability,paralysis,and eventual death is ________.

Accepted Answer

The symptoms described are typical of Tay-Sachs disease, an inherited disorder caused by a deficiency in an enzyme that leads to the accumulation of harmful substances in the brain and nerve cells. It is transmitted by recessive genes and has no cure, leading to the eventual death of affected individuals. Klinefelter's syndrome and Turner's syndrome are genetic conditions that affect the sex chromosomes and cause different physical and developmental issues, while phenylketonuria is a metabolic disorder caused by the inability to break down the amino acid phenylalanine.

Question 15

Which of the following is NOT true of fragile X syndrome?

Accepted Answer

The mutation may not always manifest itself and some individuals may not show any symptoms despite carrying the mutation. This phenomenon is known as a "premutation" carrier state, which is characterized by mild or no symptoms but can increase the risk of passing on the full mutation to future generations.

Question 16

Which of the following is NOT true of children with Down syndrome?

Accepted Answer

It is not true that most children with Down syndrome cannot learn to read or write. With appropriate teaching strategies and accommodations, many individuals with Down syndrome are capable of achieving literacy skills.

Question 17

Fragile X syndrome is caused by ________.

Accepted Answer

Fragile X syndrome is caused by a mutated gene called the FMR1 gene that results in a lack of production or reduced levels of the fragile X mental retardation protein (FMRP). It is an X-linked dominant disorder.

Question 18

Estimates of prevalence of Klinefelter's syndrome range from 1 in ________ males.

Accepted Answer

Klinefelter's syndrome, a genetic condition affecting males, has an estimated prevalence of 1 in 500 to 1 in 1000 males. This condition arises from the presence of an extra X chromosome.

Question 19

Judith is shorter than average.She has mild intellectual disability,with her greatest difficulties being in math and science.Although her external genital development is normal,her ovaries are poorly developed and she is infertile.She is suffering from ________.

Accepted Answer

The description matches the symptoms of Turner's syndrome, which is caused by the absence or partial absence of the X chromosome. This results in infertility, mild intellectual disability, and physical characteristics such as short stature. Klinefelter's syndrome involves an extra X chromosome in males, fragile X syndrome is a genetic disorder that affects cognitive and social development, and Tay-Sachs disease is a rare, fatal genetic disorder. None of these match the description given.

Question 20

Turner's syndrome involves the ________.

Accepted Answer

Turner's syndrome is a genetic disorder that affects females and is caused by the absence or abnormality of one of the X sex chromosomes. Males typically have one X and one Y sex chromosome.

Quiz 11: Abnormal Behaviour Across the Lifespan