Question 1

Kaden is very thin, has severe acne, and demonstrates poor coordination. He also produces excessive levels of testosterone. What syndrome does this describe?

Accepted Answer

C) XYY syndrome is associated with an extra Y chromosome in males, which can lead to physical and behavioral characteristics such as increased height, acne, and sometimes learning difficulties or poor coordination. Excessive testosterone levels can also be a feature.

Question 2

Jack has African American heritage and his partner, Marisol, is uncertain of her heritage since she was adopted as an infant. Jack and Marisol want to start of family but are concerned about their child having sickle cell anemia. Their best option is to consult a ______.

Accepted Answer

Genetic counselors specialize in assessing an individual or couple's risk of inherited conditions, such as sickle cell anemia, and provide information and guidance about options for family planning. They can also help individuals understand their genetic background and the role it plays in potential health risks. A fertility specialist or family physician may also be involved in the process, but a genetic counselor would be the most appropriate to address their concerns about sickle cell anemia specifically. A behavioral geneticist studies the relationship between genetics and behavior, which is not directly applicable to Jack and Marisol's situation.

Question 3

Which approach is used by a genetic counselor?

Accepted Answer

A genetic counselor constructs a family history of inheritable disorders to assess the risk of passing a genetic disorder to offspring. They also provide information and counseling to individuals or couples who are considering reproduction or who have concerns about genetic disorders.

Question 4

A medical specialty that helps prospective parents determine the risk their children will inherit chromosomal abnormalities is ______.

Accepted Answer

Genetic counseling is a medical specialty that helps prospective parents determine the risk their children will inherit chromosomal abnormalities. Obstetrics and gynecology deal with prenatal care and childbirth, while behavioral genetics focuses on how genetic and environmental factors contribute to behavior and development.

Question 5

Trenton, age 50, has Down syndrome. Compared to unaffected adults his age, Trenton is at greater risk for developing ______.

Accepted Answer

Adults with Down syndrome have a higher risk of developing Alzheimer's disease, with estimates suggesting that up to 50% of individuals with Down syndrome over the age of 50 will develop Alzheimer's disease. While individuals with Down syndrome may be at a slightly increased risk for heart disease, cystic fibrosis and Huntington's disease are not typically associated with Down syndrome.

Question 6

Which factor may case genes to mutate?

Accepted Answer

Exposure to radiation can cause mutations in genes. High-fat diet, young maternal age, and vitamin deficiencies are not known to directly cause mutations in genes.

Question 7

Today, the average life expectancy of individuals with Down syndrome is ______.

Accepted Answer

The average life expectancy of individuals with Down syndrome has increased significantly over the years, and many now live into their middle adulthood, thanks to advancements in medical care and increased societal support.

Question 8

In Africa, children who inherit a single sickle cell allele are more resistant to malarial infection and more likely to survive. This demonstrates ______.

Accepted Answer

This situation demonstrates that a mutation (in this case, inheriting a single sickle cell allele) can sometimes be beneficial.

Question 9

Which method determines chromosomal abnormalities in prospective parents?

Accepted Answer

Performing a genetic screening blood test can detect chromosomal abnormalities in prospective parents. Family history and ethnicity can provide some information, but genetic screening is a more specific and accurate method. Educating the parents about genetic concepts is important but does not necessarily determine chromosomal abnormalities.

Question 10

Marcus and J.J. grew up in the same neighborhood, which has a reputation for poverty and gang violence. Both of their fathers were violent alcoholics, and they experienced periodic homelessness. Marcus carries the low-MAOA gene, while J.J. carries the high-MAOA gene. Which statement about Marcus and J.J. is true?

Accepted Answer

The MAOA gene is related to aggression and criminal behavior, and individuals with the low-MAOA gene are more likely to exhibit these traits. Since Marcus carries the low-MAOA gene, he is at greater risk for aggression and criminal behavior in adulthood than J.J., who carries the high-MAOA gene. However, it is important to note that genetics is only one factor in the development of aggression and criminal behavior and does not determine an individual's destiny.

Question 11

Vince has one of the most common sex chromosome abnormalities which is what syndrome?

Accepted Answer

Klinefelter syndrome is one of the most common sex chromosome abnormalities and is characterized by the presence of an extra X chromosome in males, resulting in symptoms such as infertility and reduced testosterone levels. Down syndrome is a chromosomal disorder caused by an extra copy of chromosome 21, XYY syndrome is a rare condition characterized by the presence of an extra Y chromosome, and fragile X syndrome is a genetic disorder that affects both males and females and is caused by a mutation in the FMR1 gene.

Question 12

Which individual would be a good candidate for genetic counseling?

Accepted Answer

Beth, who is pregnant for the first time at 37, would be a good candidate for genetic counseling because advanced maternal age (35 years and older) is associated with an increased risk of chromosomal abnormalities in the baby, such as Down syndrome. Genetic counseling can provide information and support for screening and diagnostic options.

Question 13

What is the term for a sudden change and abnormality in the structure of genes?

Accepted Answer

A mutation is a sudden change and abnormality in the structure of genes. It can occur naturally or as a result of exposure to mutagens such as radiation, chemicals, or viruses. Mutations can cause genetic disorders or lead to the development of new traits, which may be harmful or beneficial to an organism depending on the circumstances.

Question 14

Which method involves injection of sperm into a woman for reproduction?

Accepted Answer

Artificial insemination involves injecting sperm into a woman's reproductive tract, often to overcome infertility or to allow a single woman or same-sex female couple to conceive. In vitro fertilization involves fertilizing an egg with sperm in a laboratory dish and then transferring the resulting embryo to the woman's uterus. Chorionic villus sampling and amniocentesis are prenatal diagnostic tests that involve sampling fetal tissue or fluid for genetic analysis.

Question 15

Approximately 1 in 1,000 females are born with which syndrome?

Accepted Answer

Triple X syndrome occurs in approximately 1 in 1,000 females, where they have an extra X chromosome, resulting in a total of three X chromosomes instead of the usual two. This can lead to physical and developmental differences, such as taller stature and learning difficulties. Klinefelter syndrome (A) occurs in males with an extra X chromosome and affects approximately 1 in 500-1,000 males. XYY syndrome (C) occurs in approximately 1 in 1,000 males and results in an extra Y chromosome. Fragile X (D) is a genetic condition that affects both males and females, and its prevalence is estimated to be 1 in 4,000 males and 1 in 8,000 females.

Question 16

Which method involves fertilizing ova with sperm in a dish then placing the fertilized ova in a woman's uterus?

Accepted Answer

In vitro fertilization is a method that involves fertilizing ova with sperm in a dish (in vitro) outside of the woman's body and then placing the fertilized ova in the woman's uterus. Artificial insemination involves introducing sperm into a woman's reproductive system, but fertilization occurs inside the body. Chorionic villus sampling and amniocentesis are prenatal tests that involve taking samples of the developing fetus for genetic testing, but do not involve fertilization.

Question 17

How many conceptions are estimated to include mutated chromosomes?

Accepted Answer

It is estimated that about one third of conceptions include mutated chromosomes, often leading to miscarriages or developmental issues.

Question 18

Prenatal screening likely to be recommended when ______.

Accepted Answer

Prenatal screening is typically recommended when genetic counseling has determined a risk for abnormalities. This can include factors such as family history of genetic disorders, maternal age over 35, and abnormal results from previous prenatal tests. The other options listed (B, C, D) are not necessarily indicative of a need for prenatal screening.

Question 19

Danica, age 28, is very short in stature, has an abnormally small jaw, and her neck has extra folds of skin. Danica has never ovulated and she has underdeveloped breasts. Danica was born with which syndrome?

Accepted Answer

Danica exhibits physical characteristics commonly associated with Turner syndrome, including short stature, small jaw, excess skin folds in the neck, underdeveloped breasts, and infertility due to lack of ovulation. Klinefelter syndrome involves the presence of an extra X chromosome in males, resulting in physical traits such as tall stature, small testes, and breast development. Triple X syndrome involves the presence of an extra X chromosome in females, which may lead to taller than average height, learning difficulties, and reproductive issues. Fragile X syndrome is a genetic condition that affects both males and females, most commonly causing intellectual disability and behavioral difficulties. None of the characteristics described in the question are specifically associated with Klinefelter, triple X, or fragile X syndromes.

Question 20

Which couple may find genetic counseling most useful?

Accepted Answer

Central European Jewish individuals have a higher risk of carrying certain genetic disorders, such as Tay-Sachs disease or Gaucher disease. Therefore, Noah and Ava would benefit from genetic counseling to determine their risk of passing on these disorders to their children.

Quiz 2: Biological and Environmental Foundations