Question 1

Which statement applies to the effects of exposure to harmful substances during embryonic life?
1) During the first two weeks, exposure will usually cause death of the embryo.
2) Organs or body structures may be altered by exposure during the first two months.
3) The effects of exposure depend on the stage of development at the time of exposure.
4) Metabolic abnormalities usually follow exposure to teratogens.

Accepted Answer

Exposure to harmful substances can cause death in the first two weeks, alter organs in the first two months, and effects depend on the development stage.

Question 2

What is the term for an arrangement of the chromosomes from an individual's cell, organized in pairs based on size and shape?

Accepted Answer

A karyotype is the term for an arrangement of chromosomes from an individual's cell, organized in pairs based on size and shape.

Question 3

A spontaneous alteration in genetic material that may result from exposure to harmful substances is termed:

Accepted Answer

A mutation is a spontaneous alteration in genetic material, which can occur due to exposure to harmful substances or other factors.

Question 4

Down syndrome is an example of a/an:

Accepted Answer

Down syndrome is a chromosomal disorder caused by the presence of an extra copy of chromosome 21.

Question 5

A person with sickle cell trait that is heterozygous has:

Accepted Answer

The answer of A person with sickle cell trait that...

Question 6

In the case of an X-linked recessive disorder, a carrier mother and unaffected father could produce a/an:

Accepted Answer

A carrier mother (X^X) and an unaffected father (XY) can produce a normal female (XX) if the daughter inherits the unaffected X chromosome from both parents.

Question 7

What is characteristic of a congenital disorder?

Accepted Answer

Congenital disorders are typically present at birth and often manifest in the neonatal period, although they may not always be immediately apparent.

Question 8

A father affected with hemophilia A, whose wife is unaffected, will pass on the defective gene to:

Accepted Answer

Hemophilia A is an X-linked recessive disorder. A father with hemophilia A has the defective gene on his X chromosome. He will pass this X chromosome to all of his daughters, making them carriers, while his sons receive his Y chromosome and are unaffected.

Question 9

TORCH is an acronym for routine prenatal screening tests for high-risk maternal infections; TORCH stands for:

Accepted Answer

TORCH stands for toxoplasmosis, other (hepatitis B, mumps, rubeola, varicella, gonorrhea, syphilis), rubella, cytomegalovirus, and herpes.

Question 10

Which of the following statements applies to Huntington's disease?

Accepted Answer

Huntington's disease is caused by a single defective gene on chromosome 4, and there is a genetic test available to identify this mutation. It is an autosomal dominant disorder, meaning only one copy of the defective gene, inherited from an affected parent, is sufficient to cause the disease.

Question 11

A mother is a carrier of Duchenne muscular dystrophy; the father is unaffected. They have one son with muscular dystrophy. Another male child is expected. The probability of the second son having muscular dystrophy is:

Accepted Answer

Duchenne muscular dystrophy is an X-linked recessive disorder. The mother, being a carrier, has a 50% chance of passing the affected X chromosome to her son, resulting in a 50% probability that the second son will have the disorder.

Question 12

Agents that cause damage during embryonic or fetal development are called:

Accepted Answer

Teratogenic agents are substances that can cause congenital abnormalities or birth defects during embryonic or fetal development.

Question 13

Exposure to cocaine during pregnancy leads to increased risk of:

Accepted Answer

Cocaine exposure during pregnancy is associated with an increased risk of premature birth, respiratory problems, and sudden infant death syndrome (SIDS).

Question 14

Which of the following are common manifestations of Down syndrome?
1) Congenital heart defect
2) Cleft lip and palate
3) Large protruding tongue
4) Limited intellectual development

Accepted Answer

Down syndrome commonly presents with congenital heart defects, a large protruding tongue, and limited intellectual development. Cleft lip and palate are not typically associated with Down syndrome.

Question 15

What is an example of a multifactorial congenital disorder?

Accepted Answer

Cleft lip and palate is a multifactorial congenital disorder, meaning it is caused by a combination of genetic and environmental factors.

Question 16

Ultrasonography during pregnancy would be helpful in detecting fetal:

Accepted Answer

Ultrasonography is a non-invasive imaging technique that uses high-frequency sound waves to produce images of the fetus. It is commonly used during pregnancy to assess fetal growth and development, and to detect structural anomalies.

Question 17

Hemophilia A has been diagnosed in a young boy. He has inherited this defective gene from:

Accepted Answer

Hemophilia A is an X-linked recessive disorder, meaning the defective gene is located on the X chromosome. Males inherit their X chromosome from their mother, so the boy inherited the defective gene from his mother.

Question 18

What is the probability of two parents, both carriers of a defective recessive gene, producing a homozygous child (with each pregnancy)?

Accepted Answer

When both parents are carriers of a recessive gene, there is a 25% chance that the child will inherit two copies of the recessive gene, making them homozygous for that gene.

Question 19

Which of the following statements applies to the sex chromosomes?

Accepted Answer

Sex chromosomes are numbered as pair 23 in the karyotype. In humans, females have XX and males have XY sex chromosomes.

Question 20

Which of the following statements regarding Down syndrome is TRUE?

Accepted Answer

The typical physical characteristics of Down syndrome, such as distinct facial features, are usually present at birth.

Quiz 21: Congenital and Genetic Disorders