Question 1

Scientists have discovered that carrying the sickle-cell gene raises immunity to _______, which is a common disease in West Africa.

Accepted Answer

Studies have shown that individuals who carry the sickle-cell gene are less likely to be affected by malaria as the gene provides some protection against the disease.

Question 2

What is the name of the earliest prenatal test that occurs in the 11^th to 13^th week of pregnancy and can identify chromosomal abnormalities and other disorders, such as heart problems?

Accepted Answer

Ultrasound sonography is the earliest prenatal test that occurs in the 11th to 13th week of pregnancy and can identify chromosomal abnormalities and other disorders, such as heart problems.

Question 3

Which test is most often performed at 8 to 11 weeks, and involves inserting a needle (abdominally) or a catheter (cervically) into the substance of the placenta (but staying outside the amniotic sac) and removing 10 to 15 milligrams of tissue, which is cleaned of maternal uterine tissue, and then grown in a culture so that a karyotype can be made?

Accepted Answer

Chorionic villus sampling (CVS) is the procedure described, which involves taking a sample of tissue from the placenta to test for chromosomal abnormalities and other genetic problems in the fetus.

Question 4

Which test is carried out 15 to 20 weeks into the pregnancy and allows the analysis of fetal cells that can identify a variety of genetic defects with nearly 100% accuracy?

Accepted Answer

The test described in the question is amniocentesis, which is a medical procedure in which a small amount of amniotic fluid is removed from the sac surrounding the fetus and analyzed for genetic abnormalities. It is typically performed between 15 and 20 weeks into the pregnancy and has a high degree of accuracy in identifying genetic defects.

Question 5

Humans have about ______ genes.

Accepted Answer

Humans have approximately 25,000 genes. While initially it was thought that humans would have around 100,000 genes, advances in sequencing technology have shown that the actual number of protein-coding genes is much smaller than expected. In fact, studies have found that humans have only slightly more genes than the roundworm Caenorhabditis elegans, which has approximately 20,000 genes. Therefore, Option B is the best choice.

Question 6

Huela is going to have her first child and talks to her physician about assessing the health of her unborn child.The physician recommends a test which combines a blood test and ultrasound sonography.Which procedure was recommended?

Accepted Answer

The first-trimester screen is a prenatal test that combines a blood test with an ultrasound sonography to assess the risk of certain chromosomal conditions in the unborn child, such as Down syndrome. This test is typically performed between the 11th and 13th weeks of pregnancy.

Question 7

Which prenatal test, usually performed between 8 and 11 weeks, produces a risk of miscarriage of 1 in 100 to 1 in 200 pregnancies?

Accepted Answer

Chorionic villus sampling (CVS) is a prenatal test conducted between 8 and 11 weeks of pregnancy that involves taking a sample of tissue from the placenta to test for chromosomal abnormalities and certain other genetic problems. The procedure carries a risk of miscarriage, which is estimated to be about 1 in 100 to 1 in 200 pregnancies.

Question 8

Sue has an inherited disorder that is produced by an injury to a gene on the X chromosome, producing mild to moderate mental retardation.She has

Accepted Answer

Fragile X syndrome is the only inherited disorder in the answer choices caused by an injury to a gene on the X chromosome. Down syndrome is caused by an extra copy of chromosome 21, Tay-Sachs disease is a lysosomal storage disorder, and Klinefelter's syndrome involves an extra X chromosome in males.

Question 9

What is the profession that focuses on helping people deal with issues relating to inherited disorders?

Accepted Answer

Genetic counselling is the profession that deals with helping people understand and cope with issues related to inherited disorders. Genetic counselors provide information and support to individuals and families who may be at risk for genetic conditions, and help them make informed decisions about genetic testing, medical management, and family planning.

Question 10

Sometimes genes, for no known reason, change their form in a process called

Accepted Answer

Spontaneous mutation is the correct term for when genes change their form for no known reason. This process can lead to variations within the genetic material of organisms.

Question 11

Amniocentesis is carried out _____ weeks into the pregnancy.

Accepted Answer

Amniocentesis is carried out between 15-20 weeks into the pregnancy. This is because during this time, there is enough amniotic fluid to safely extract a sample for testing, and the fetal cells have developed enough for accurate analysis.

Question 12

Name the process of identifying genetic defects by examining a small sample of fetal cells that are drawn by a needle inserted into the amniotic fluid surrounding the unborn fetus.

Accepted Answer

This process is called amniocentesis, where a needle is inserted into the amniotic fluid surrounding the fetus to extract a small sample of fetal cells for genetic testing. Karyotype is a genetic test that analyzes the number, size, and shape of chromosomes, but it is not necessarily used in this specific method of testing. Ultrasound sonography is a noninvasive imaging technique that uses sound waves to create pictures of the inside of the body, including the fetus, but it does not involve genetic testing. Chorionic villus sampling (CVS) is another prenatal genetic testing method, but it involves taking a sample of the placenta for genetic analysis, not the amniotic fluid.

Question 13

Jamal has an extra chromosome on the twenty-first pair of chromosomes, causing him to have

Accepted Answer

Down syndrome is caused by the presence of an extra chromosome on the twenty-first pair of chromosomes. Hemophilia is an inherited disorder that affects the blood's ability to clot and is caused by a mutation in one of the clotting factor genes. Fragile X syndrome is a genetic disorder caused by a mutation in the FMR1 gene, which affects cognitive and behavioral development. Sickle-cell anemia is a genetic disorder caused by a mutation in the HBB gene, which affects the production of hemoglobin and causes red blood cells to become misshapen.

Question 14

What process is used to find genetic defects, and involves taking samples of the hair-like material that surrounds the embryo?

Accepted Answer

Chorionic villus sampling (CVS) is the process used to find genetic defects by taking samples of the chorionic villi, which are hair-like materials surrounding the embryo.

Question 15

What is the process in which high-frequency sound waves scan the mother's womb to produce an image of the unborn baby, whose size and shape can then be assessed?

Accepted Answer

Ultrasound sonography uses high-frequency sound waves to create images of the inside of the body, including the womb, to assess the development of the unborn baby.

Question 16

Tara has a disorder that is untreatable and produces blindness and muscle degeneration prior to death.Her diagnosis would be

Accepted Answer

The symptoms described in the question match those of Tay-Sachs disease, which is an untreatable genetic disorder that affects the nervous system and leads to blindness and muscle degeneration. Fragile X syndrome involves intellectual disabilities, Klinefelter's syndrome involves infertility and hormonal imbalances, and hemophilia involves difficulty with blood clotting.

Question 17

Toni has a blood disorder that gets its name from the shape of the red blood cells.She would be diagnosed with what disorder?

Accepted Answer

The blood disorder that gets its name from the shape of the red blood cells is sickle-cell anemia. Patients with sickle-cell anemia have crescent-shaped red blood cells instead of the normal round ones.

Question 18

What is the more invasive prenatal test that can be employed if blood tests and ultrasound have identified a potential problem, or if there is a family history of inherited disorders?

Accepted Answer

Chorionic villus sampling (CVS) is a more invasive prenatal test compared to blood tests and ultrasound sonography. It involves taking a sample of tissue from the placenta to test for chromosomal abnormalities and certain genetic problems, offering early and accurate diagnosis.

Question 19

Akili has the disorder that results from the presence of an extra X chromosome that produces underdeveloped genitals, extreme height, and enlarged breasts.She has

Accepted Answer

Klinefelter's syndrome is characterized by the presence of an extra X chromosome in males, leading to symptoms such as underdeveloped genitals, taller than average height, and enlarged breasts.

Question 20

Which test can be used to determine the sex of the child?

Accepted Answer

Amniocentesis can be used to determine the sex of the child by analyzing the chromosomes in the fetal cells obtained from the amniotic fluid.

Quiz 2: The Start of Life