question

Which of the following will be important for the continued development of chemotherapeutic agents to better fight cancer?

answer

identification of compounds from new species of plants and animals from varied environments development of synthetic compounds that mimic naturally occurring compounds with anticancer effects efficient and effective delivery of chemotherapeutic agents to individuals with cancer screening systems to look for potential compounds with anticancer properties

question

A patient has metastatic melanoma (skin cancer). Is surgery a viable option for this patient?

answer

No, because the cancerous cells have spread throughout the body.

question

In the development of chemotherapeutic agents for cancer, what factors must be considered?

answer

environmental costs if the agent is from a living specimen production costs if the agent is rare or hard to isolate side effects the drug may have on noncancerous cells

question

Which of the following processes require normal cell division?

answer

embryonic development wound healing replacement of blood cells intestinal tract and skin cell replacement

question

During which stage of the cell cycle are sister chromatids initially produced?

answer

interphase

question

Why would the cell make apoptosis the default mechanism when a problem in the cell cycle is detected?

answer

Apoptosis ensures that the cell dies instead of leading to cancer.

question

Which of the following series has the stages of the cell cycle in the proper order?

answer

G1, S, G2, mitosis, cytokinesis

question

Which is the best definition of cancer?

answer

a disease in which unregulated cell division occurs

question

When your skin cells are exposed to UV light, such as in a tanning bed, DNA damage can occur. If one of these severely UV-irradiated skin cells is given a signal to divide, what are plausible outcomes?

answer

The cell will go through apoptosis, after the damage is detected.

question

What would be the result if a cell completed interphase and mitosis but failed to complete cytokinesis?

answer

You would only have one cell. You would have twice as many chromosomes as the parent cell.

question

During which stage of the cell cycle do sister chromatids separate from each other?

answer

anaphase

question

Which checkpoint prevents a normal cell from completing its cell cycle if it has not accurately replicated its DNA?

answer

interphase (G2-M)

question

Following mitosis and cytokinesis, daughter cells are __________.

answer

genetically identical to each other genetically identical to the parent cell

question

In which stage of the cell cycle does the cell spend the most time?

answer

interphase

question

Cell cycle checkpoints are present to _________.

answer

prevent mistakes in the course of cell division that lead to cancer ensure that each step of the cell cycle occurs accurately.

question

A normal cell that sustains irreparable DNA damage will most likely __________.

answer

die by apoptosis

question

In the cell cycle, DNA is replicated during _______.

answer

S

question

Which of the following series has the stages of mitosis in the proper order?

answer

prophase, metaphase, anaphase, telophase

question

Which of the following properties should a promising new ovarian cancer drug have?

answer

blocks mitosis in cancerous cells

question

Which types of cells are triggered to go through apoptosis by radiation and chemotherapy treatments?

answer

any cell that is rapidly undergoing cell division

question

If an individual has a germline mutation, which of the following are possible sources of that mutation?

answer

a maternal allele a paternal allele

question

Which of the following statements accurately describes cancer development?

answer

It is a multistep process by which multiple mutations cause a series of events that lead to cancer.

question

Why does wearing sunscreen reduce cancer risk?

answer

Sunscreen can reduce the chance of mutations caused by exposure to UV radiation present in sunlight.

question

DNA mutations can arise from uncorrected errors in DNA replication, inheritance, and __________.

answer

environmental insults

question

A woman with a BRCA1 mutation __________.

answer

is at increased risk of developing breast cancer

question

A chemical that causes alterations in DNA is a ______________, and if this chemical causes cancer it is called a _______________.

answer

mutagen; carcinogen

question

What would you say to a niece if she asked you how she could reduce her risk of breast cancer? (Assume there is no family history of breast cancer.)

answer

Reduce sun exposure. Reduce alcohol consumption. Avoid tobacco. Utilize early screening.

question

Tumors that will not spread throughout the body are _________________, and those that do spread are termed ______________.

answer

benign; malignant

question

What is the role of BRCA1 in normal cells?

answer

BRCA1 acts as a tumor suppressor.

question

Why do people with "inherited cancer" often develop cancer at a relatively young age?

answer

Predisposition increases the chances that other risk factors will lead to the progression of cancer. Cancer cannot be truly inherited, but certain alleles weaken the normal control points that prevent cancer, and this causes cancer to appear earlier in life.

question

A mutation can cause a change __________.

answer

in the amino acid sequence of a protein in the shape of a protein in the way the cell cycle is regulated that is beneficial to the cell

question

Why is age a risk factor for cancer?

answer

The older a person is the more times potentially cancer-causing mutations can be acquired. Age extends the amount of exposures to environmental factors, which can lead to the progression of cancer.

question

Which of the following does not cause cancer to develop and progress?

answer

a proto-oncogene a tumor suppressor gene

question

In an otherwise normal cell, what happens if one mistake is made during DNA replication?

answer

A cell cycle checkpoint detects the error and pauses the cell cycle so the error can be corrected.

question

Which of the following women would be most likely to benefit from genetic testing for breast cancer?

answer

a 25-year-old woman whose mother, aunt, and grandmother had breast cancer

question

A potential cancer-causing gene coding for a protein with cell cycle control responsibilities is a ___________, and a gene coding for a protein that stimulates cell division is a ___________.

answer

tumor suppressor; proto-oncogene

question

Which is the correct order of events in which breast cancer might develop?

answer

inheritance of a mutant BRCA gene > replication errors create an oncogene > mutation of p53 > additional mutations permit spreading

question

At which of the following points does a mutation exert its potentially dysfunctional effects in a cell?

answer

after a protein is produced

question

We would all have many more mutations in our genes if not for the __________.

answer

activity of proofreading enzymes

question

A woman is heterozygous for the CF-associated gene (the alleles are represented here by the letters A and a). Assuming that meiosis occurs normally, which of the following represent eggs that she can produce?

answer

A and a

question

Women can inherit alleles of a gene called BRCA1 that puts them at higher risk for breast cancer. The alleles associated with elevated cancer risk are dominant. Of the genotypes listed below, which carries the lowest genetic risk of developing breast cancer?

answer

bb

question

What does it mean to say that a person is a heterozygous carrier for a genetic disease?

answer

That person does not show symptoms of the disease if the disease allele is recessive.

question

Phenylketonuria is considered to be an inborn error of metabolism. It is a recessive genetic condition in which the enzyme that breaks down the amino acid phenylalanine is defective or missing. Testing of all newborns allows this condition to be detected at birth. A special diet that severely minimizes phenylalanine (e.g., by avoiding diet sodas and most usual sources of protein) can treat the condition. In this scenario, two carriers of both cystic fibrosis and phenylketonuria have a child. What is the probability that the child will have both cystic fibrosis and phenylketonuria?

answer

1/16

question

Children often have many of the phenotypes of their parents because __________.

answer

they inherit half of their genetic material from each parent

question

Why is it possible for two healthy parents to give birth to a child with a genetic defect such as cystic fibrosis?

answer

CF is only evident in individuals with two mutant alleles; a healthy parent could carry both a defective allele and a normal copy and be healthy.

question

Assume that Emily (who has CF, a recessive disease (aa)) decides to have children with a man who does not have CF and who has no family history of CF. What combination of gametes can each of them produce, and what is the probability that they will have a child who is a carrier for CF?

answer

Emily: aa and man: AA; 100% probability

question

Meiosis differs from mitosis in the __________.

answer

number of chromosomes in each ending cell

question

Which of the following is(are) TRUE of a single human gamete?

answer

There is one allele on each chromosome.

question

One of the purposes of meiosis is to __________.

answer

reduce the chromosome number in each cell by half.

question

Phenylketonuria is considered to be an inborn error of metabolism. It is a recessive genetic condition in which the enzyme that breaks down the amino acid phenylalanine is defective or missing. Testing of all newborns allows this condition to be detected at birth. A special diet that severely minimizes phenylalanine (e.g., by avoiding diet sodas and most usual sources of protein) can treat the condition. In this scenario, two carriers of both cystic fibrosis and phenylketonuria have a child. What is the probability that the child will have cystic fibrosis and be a carrier for phenylketonuria?

answer

2/16

question

Besides recombination, what other event in meiosis increases the genetic diversity of the gametes?

answer

the random line-up and separation of maternal and paternal chromosomes

question

What is the genotype of a person with cystic fibrosis?

answer

The genotype includes two mutant CFTR genes, one each on the homologous chromosomes for chromosome 7.

question

A human female has _____ chromosomes in each skin cell and ______ chromosomes in each egg.

answer

46; 23

question

Which of the following accurately describes meiosis?

answer

contains two rounds of division (meiosis I and meiosis II) ends with four gametes that are not the same genetically

question

An alien has 82 total chromosomes in each of its body cells. The chromosomes are paired, making 41 pairs. If the alien's gametes undergo meiosis, what are the number and arrangement (paired or not) of chromosomes in one of its gametes?

answer

41 unpaired chromosomes

question

How do the two alleles of the CFTR gene in a lung cell differ?

answer

They are inherited from different parents.

question

In diploid organisms, having two homologues of each chromosome can be beneficial if one allele of a gene encodes a nonfunctional protein. Can haploid organisms survive the presence of nonfunctional alleles?

answer

No, because there is only one allele for the gene in each cell, and the nonfunctional allele has no other allele to mask it.

question

Which of the following is(are) TRUE of a single human liver cell?

answer

There are 46 chromosomes present. There are two alleles for each gene. There is one allele on each chromosome.

question

A diploid cell of baker's yeast has 32 chromosomes. How many chromosomes are in each of its haploid spores?

answer

16

question

How are polygenic and multifactorial traits different?

answer

Polygenic traits are genetically based, whereas multifactorial traits have both genetic and environmental influences.

question

Which of the following inheritance patterns includes an environmental contribution?

answer

multifactorial

question

Human skin color ranges from very light to dark black, with many distinct skin tones in between. Neglecting for a moment that skin color can be affected by sun exposure, what type of inheritance pattern probably governs skin color?

answer

polygenic inheritance

question

What is different about red blood cells from a person with type AB blood, compared to those from other blood types?

answer

They carry A and B type surface markers, so they are universal acceptors of blood.

question

Which of the following can be determined by amniocentesis and karyotyping?

answer

trisomy 21

question

Why are more males than females affected by X-linked recessive genetic diseases?

answer

because males have a Y chromosome that does not represent the same alleles as the X chromosomes and cannot mask the X-linked recessive allele because females have an additional X chromosome to mask the X-linked recessive allele

question

Why do some people have unusual chromosome combinations, such as XYY and XXX?

answer

Errors occurred in chromosome segregation during meiosis in their fathers or mothers.

question

If a man has an X-linked recessive disease, can his sons inherit that disease from him?

answer

No, all his sons inherit their X chromosomes maternally

question

A gamete is aneuploid if __________.

answer

one or more homologous chromosomes fail to separate in meiosis I one or more sister chromatids fail to separate in meiosis II there are more than 23 chromosomes in the cell there are fewer than 23 chromosomes in the cell

question

Predict the sex of a baby with an XXY pair of sex chromosomes.

answer

male

question

Predict the sex of a baby with an XX pair of sex chromosomes.

answer

female

question

Which of the following can result in a trisomy such as Down syndrome?

answer

an egg with 24 chromosomes fertilized by a sperm with 23 chromosomes

question

Which of the following is TRUE about Y chromosome analysis?

answer

It is commonly used to determine paternity and ancestry.

question

Consider your brother and your son. If you are male, which will have essentially identical Y chromosomes?

answer

You and your brother inherited the same Y chromosome from your dad, and you passed the same Y chromosome on to your son.

question

Which of the following most influences the development of a female fetus?

answer

the absence of a Y chromosome

question

Which of the following couples could have a boy with Duchenne muscular dystrophy (DMD)?

answer

a male without DMD and a carrier female

question

How is codominant inheritance different from incomplete dominant inheritance?

answer

In codominance, two alleles are expressed equally; in incomplete dominance, neither the dominant or recessive phenotype is seen in heterozygotes.

question

Which of the following is a likely result of nondisjunction in human meiosis?

answer

aneuploid eggs and sperm

question

Why is type O Rh-negative the "universal donor"?

answer

No surface markers are present on the O Rh-negative blood cells to react with the recipient's immune system.

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