Chapter 15 biology test

Lucille has her own personal genome analyzed. The report state that her genome includes one copy of the defective allele that causes cystic fibrosis, an autosomal recessive disease. Lucille is surprised by the report, because she is unaware of the disease in her family history, and she shows no symptoms of it. Lucille asks a genetic counselor if her future children are at risk for suffering the symptoms of cystic fibrosis. Which of the following replies is the most accurate response to Lucille's question?

A future child might suffer from cystic fibrosis if the father's genetic report is the same as Lucille's report.

Based on the pedigree, are short eyelashes determines by a recessive allele or a dominant allele? What reason explains this answer?

A recessive allele, because two parents with long eyelashes can have children with short eyelashes.

Some of the family members must be heterozygous for the trait of eyelash length, meaning their genotypes include one allele for long eyelashes and one allele for short eyelashes. In which generation are these family members ?

I., II., III.

In recent years, scientists and the public have raised a number of ethical and legal questions about DNA. Many of the questions involve issues of ownership and privacy of personal genetic information. Issues like these became relevant to society because which of these scientific achievements?

The completion of the Human Genome Project

Mr. and Mrs. Howard are deciding whether to have children. A physician advises them both to be tested for the allele that causes Tay-Sachs Disease, which is a fatal genetic disorder. "Neither of us have Tay-Sachs Disease, so how could our children inherit it?" Which id the most accurate and useful response to the Howards' question?

Tay-Sachs is caused by a recessive allele, so you both could be carriers.

Because two copies of a defective CF allele are needed to produce cystic fibrosis,

The CF allele is recessive.

Gel electrophoresis is successful because of which property of DNA fragments?

The DNA fragments travel at different speeds through the gel.

Raul is using a computer model to investigate meiosis. He directs the model to show a nondisjunction of chromosome 21 during meiosis 1. How many copies of chromosome 21 should the model display in each gamete that is produced?

either 2 copies or no copies

A scientist describes the karyotype of a human egg cell as (23, X). The egg cell unites with a sperm cell to form the first cell of a healthy baby boy. What is the karyotype of the sperm cell?

(23, Y)

Three family members each have short eyelashes. These family members include one male and two females. Which statement accurately compared the genotypes for eyelash length among the three family members?

All three of the family members have the same genotype for eyelash length.

The diagram shows a restriction enzyme, called Baml, that is attached to a section of a DNA molecule. How will restriction enzyme act?

It will cause a point mutation, such as by substituting guanine (G) for cytosine (C).

A scientist has identified a protein that she claims is the product of a sex-linked gene. To gather evidence to support this claim, which action would be MOST useful for the scientist to take?

Locate the gene on the X or Y chromosome.

Can the gender of the patient (male or female) be identified from the section of the karyotype shown here?

No

The man with short eyelashes in Generation II marries a woman with long eyelashes. This woman reports that everyone in her family also has long eyelashes. Can the man and woman be sure that all of their children will have long eyelashes?

No

Which of the following disorders does NOT result from nondisjunction during meiosis?

Sickle Cell Disorder

Sickle cell disease and cystic fibrosis are both serious genetic disorders. Which statement provides the strongest explanation for why the alleles remain relatively common in the human population?

The disease-causing alleles continue to arise from mutations to normal genes.

Steven develops a pedigree for earlobe attachment in a large family. Earlobes can be either free or attached. What information about earlobe attachment can Steven MOST LIKELY determine by analyzing the pedigree?

The dominant and recessive forms of the trait.

Which of these statements accurately compares the human genome to the genomes ?

The human genome contains the greatest number of base pairs of DNA.

Frida is studying an example of a human karyotype. She makes the following claim about the karyotype. "i can determine which sex chromosome was donated by the female parent." Fridas claim is accurate under which of these conditions?

The karyotype was taken from a male.

The diagram below shows a section of a karyotype. The karyotype was created from a cell sample that was obtained from a parent at a hospital. Which conclusion about the patient do the karyotype data most strongly support?

The patient has an abnormal number of autosomes that likely is causing severe symptoms.

Which pair of DNA fragments would be least likely to separate during gel electrophoresis?

Two fragments of the same length

A karyotype is assembled from the cell of a human donor who has a genetic disorder. Which disorder can be determined by studying the karyotype?

a chromosomal disorder, such as Down syndrome.

Horace is using a computer model to study the relationship between the genes and phenotype of an individual. In one experiment, Horace alters the nucleotide sequence in individual changes from brown to blue. How did the change in the gene cause the change in the phenotype?

by affecting the amino acid sequence of a protein.

A genetic disorder is caused by an allele of a sex-linked gene, located on the y chromosome. is the disorder inherited?

only from the father to a son

A scientist has divided a DNA molecule into several fragments. Next, the scientist would use gel electrophoresis to accomplish which task?

separating the fragments by size