Question 1

Which of the following is the most common sex-chromosome anomaly?

Accepted Answer

The answer of Which of the following is the most...

Question 2

Not long after Gloria found out she was pregnant, she began having pain. When she went to her doctor, she was told that the zygote had implanted in her fallopian tube rather than in her uterus. What type of pregnancy is this?

Accepted Answer

This is an ectopic pregnancy, which is when the fertilized egg implants outside of the uterus. In this case, it has implanted in the fallopian tube. This type of pregnancy is dangerous and requires medical intervention.

Question 3

Which of the following is associated with the second trimester of pregnancy?

Accepted Answer

Movements of the fetus are typically felt by the mother during the second trimester, as the fetus becomes more active and begins to grow larger. A mucus "plug" typically forms later in pregnancy, and implantation of the zygote occurs in the first trimester. Nausea is typically associated with the first trimester.

Question 4

What is a trisomy?

Accepted Answer

Trisomy refers to having three copies of a specific autosome, instead of the usual two. The most well-known trisomies include Down syndrome (trisomy 21), Edwards syndrome (trisomy 18), and Patau syndrome (trisomy 13).

Question 5

Which of the following is an autosomal dominant disorder?

Accepted Answer

Huntington's disease is the only autosomal dominant disorder among the given options. Phenylketonuria and Tay-Sachs disease are autosomal recessive disorders, while sickle-cell disease is an autosomal co-dominant disorder.

Question 6

Reese is taller than average and has larger than usual teeth. Some people used to think that people like Reese would be aggressive and not very bright. With which of the following was Reese most likely born?

Accepted Answer

Reese's characteristics of being taller than average and having larger than usual teeth are often associated with having an extra Y chromosome, also known as XYY syndrome. This condition has historically been linked to stereotypes of increased aggression and lower intelligence, although these views are outdated and not supported by current research.

Question 7

Which of the following terms describes physical traits which are influenced by both genes and the environment?

Accepted Answer

Multifactorial traits are influenced by both genetic and environmental factors. This means that the phenotype (physical trait) is determined by the interaction between multiple genes and environmental factors. Examples of multifactorial traits include height, weight, and susceptibility to certain diseases.

Question 8

Samson is taller and has a higher IQ than either of his parents. Which of the following terms would be used to explain this?

Accepted Answer

Multi-factorial inheritance refers to traits that are influenced by both genetic and environmental factors. Samson's height and IQ are likely influenced by both his inherited genes and environmental factors, such as nutrition and education. The other options (adoption, environmentally influenced inheritance, and polygenetic inheritance) do not fully explain Samson's characteristics.

Question 9

Which of these genetic disorders usually does not express symptoms until adulthood?

Accepted Answer

Huntington's disease is a neurodegenerative disorder that usually does not express symptoms until adulthood, typically between the ages of 30 and 50, whereas Tay-Sachs disease, Sickle-cell disease, and Phenylketonuria usually express symptoms earlier in life or at birth.

Question 10

What percent of congenital disorders are a result of harmful genes or faulty chromosomes?

Accepted Answer

Congenital disorders are birth defects that are present at birth. They can be caused by a variety of factors, including harmful genes or faulty chromosomes. Approximately 30% of congenital disorders are caused by harmful genes or faulty chromosomes.

Question 11

Which of the following is caused by a gene on the X chromosome?

Accepted Answer

Color blindness is caused by a gene on the X chromosome, and is therefore a sex-linked trait. Tay-Sachs disease is caused by a mutated gene on chromosome 15, PKU is caused by a mutation on an autosomal chromosome, and sickle-cell disease is caused by a mutation on chromosome 11.

Question 12

Which of the following is a condition that can cause a baby to grow too rapidly and result in premature labor or an infant that is too large for a vaginal birth?

Accepted Answer

Gestational diabetes can cause the baby to receive too much glucose, leading to excessive growth and potential complications during labor and delivery.

Question 13

Phenylketonuria is an example of which of the following?

Accepted Answer

Phenylketonuria is an autosomal disorder, meaning the affected gene is located on an autosome, which is any chromosome that is not a sex chromosome. It is inherited in an autosomal recessive pattern.

Question 14

Which of the following happens during the first trimester of pregnancy?

Accepted Answer

The zygote implants itself in the lining of the uterus during the first trimester of pregnancy. Chemical messages are sent to the brain to stop, not start, menstruation when a woman becomes pregnant. A woman can still detect pregnancy using a urine test during the first trimester. The cervix thins and stretches during the last trimester of pregnancy, not the first.

Question 15

Which of the following is one of the ideas summarized by Rutter et al. regarding multi-factorial inheritance?

Accepted Answer

Rutter et al. summarize the idea of multi-factorial inheritance as an interaction between nature (genes) and nurture (environment).

Question 16

Janae and Sean are siblings who come from a family with a history of anxiety. Janae is somewhat anxious but generally takes things in stride. Sean, however, is always concerned about his health, his job, and his family even when there is no reason. Which of the following concepts proposed by Michael Rutter best explains the difference between Janae and Sean?

Accepted Answer

Multifactorial inheritance suggests that traits such as anxiety are influenced by both genetic and environmental factors. This concept accounts for the variation in anxiety levels between Janae and Sean, as they may have inherited different combinations of genes that predispose them to anxiety, and may have been exposed to different environmental stressors throughout their lives. Epigenetic genetics, dominant and recessive traits, and mitochondrial inheritance do not specifically address the role of genetic and environmental factors in complex traits like anxiety.

Question 17

What is the prognosis for children born with trisomy 13 or 18?

Accepted Answer

Children born with trisomy 13 or 18 have a very poor prognosis, with many not surviving past infancy. These conditions are often associated with multiple birth defects and medical complications, making it difficult for them to survive.

Question 18

Most sex-linked disorders are caused by which of the following?

Accepted Answer

Sex-linked disorders are caused by mutations in genes located on the sex chromosomes (X or Y). Most of the sex-linked diseases are recessive, meaning that they require two copies of the mutated gene (one on each X chromosome) to produce the disorder. Dominant genes are less common, and they only require one copy of the mutated gene to cause the condition. Maternal alcoholism and fetal alcohol syndrome are not sex-linked disorders but are instead caused by the exposure of the developing fetus to alcohol during pregnancy.

Question 19

Which of the following is typical for individuals who have sex chromosome anomalies?

Accepted Answer

Sex chromosome anomalies, such as Turner syndrome or Klinefelter syndrome, can be associated with learning difficulties due to differences in brain development. A, B, and D are not necessarily typical or common characteristics of individuals with sex chromosome anomalies.

Question 20

Which of the following individuals has the greatest risk for bearing a child with trisomy 21?

Accepted Answer

Advanced maternal age is the greatest risk factor for having a child with trisomy 21, also known as Down syndrome. The risk increases significantly after age 35 and is highest for women over 45. The other factors listed may increase the risk of various complications during pregnancy, but they are not specifically associated with an increased risk of Down syndrome.

Quiz 3: Prenatal Development and Birth