Answer Key Genetics 2019-2020 and notes PDF

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Answer Key Genetics 2019-2020, notes and questions,...

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Chapter 1: DNA Structure and Function ____

1. In which body or cell area are most genes in humans located? A. Nucleus

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2. Which condition or statement exemplifies the concept of genomics rather than genetics? A. The gene for insulin is located on chromosome 11 in all people.

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3. What is the purpose of phosphorous in a DNA strand? A. Linking the nucleotides into a strand

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4. What is the term used to define alternative forms of a gene that may result in different expression of

the trait coded for by that gene? A. Alleles ____

5. What percentage of bases in a stretch of double-stranded DNA that contains 30% guanine (G) bases

would be adenine (A)? D. 20% ____

6. What is the term used to describe the organized picture of the paired chromosomes within a cell used

to determine whether chromosome numbers, structures, and banding patterns are normal? C. Karyotype ____

7. What would be the sequence of DNA that is complementary to a DNA section with the base

sequence of GGTCAATCCTTAG? D. CCAGTTAGGAATC ____

8. Which of these complementary base pairs form the strongest or “tightest” association? B. Cytosine and guanine

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9. What activity occurs during M phase of the cell cycle? C. All DNA is completely replicated.

____ 10. Which chromosome number represents the euploid state for normal human somatic cells? B. 46 ____ 11. How does the proteome differ from the genome? A. The proteome changes in response to intracellular and extracellular signals. ____ 12. What is the most outstanding feature of a mature haploid cell? C. Only one chromosome of each pair is present. ____ 13. At what phase of the cell cycle are chromosomes visible as separate structures? D. M ____ 14. Which statement about the cell cycle phase of G0 is true? B. Performance of specific differentiated functions ____ 15. What is the result of normal DNA replication? B. Formation of two identical sets of DNA ____ 16. Which statement regarding chromosome structure or function is true? A. The chromatids of any single chromosome are known as “sister chromatids.”

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____ 17. Why does a person with normal chromosomes only have two alleles for any single gene trait? C. One allele for the monogenic trait is on the paternally derived chromosome, and

the other allele is on the maternally derived chromosome. ____ 18. Under what normal condition are genotype and phenotype always the same? C. Homozygosity of alleles ____ 19. What would be the expected result of a drug that affected a particular tissue by causing new DNA to

form with covalent bonds instead of hydrogen bonds? D. The new cells that formed within this tissue would not be able to complete the next round of mitosis successfully. ____ 20. How does the DNA enzyme topoisomerase contribute to DNA replication? D. Connects and links the individual pieces of newly synthesized DNA to form a

single strand ____ 21. Where is telomeric DNA located? A. At the tips of the p and q arms of chromosomes. ____ 22. What is the purpose of a chromosome centromere? A. Connecting sister chromatids to form a chromosome ____ 23. Which genetic process would be disrupted in one cell if it could not form chromosomes? C. Delivery of genetic information to new cells ____ 24. What are the expected expressed blood types of children born to a mother who is B/O for blood type

and a father who is A/B for blood type? B. 25% A, 50% B, 0% O, 25% AB ____ 25. A person’s karyotype shows 44 autosomes and one X chromosome. What is the best interpretation of

this karyotype? A. The karyotype is aneuploid, and the individual has only one allele for each of the genes on the X chromosome

Chapter 2: Protein Synthesis ____

1. What is the relationship among genes, DNA, and proteins? C. A gene is a section of DNA that provides the directions for synthesizing a specific

protein. ____

2. What is the best meaning for the term gene expression? B. The specific trait or protein coded for by a single gene is actually present

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3. What is the difference between DNA transcription for DNA synthesis and DNA transcription for

protein synthesis? D. Transcription for DNA synthesis occurs with both the “sense” and the “antisense” strands, while transcription for protein synthesis occurs with only the “antisense” strand. ____

4. Which mature messenger RNA strand correctly reflects the accurate transcription of the following

segment of DNA, in which large letters represent introns and small letters represent exons? tTGCGaAccaGaCTtaaAAtTAAA A. AUGGUUAUUA Copyright © 2018 F. A. Davis Company

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5. What is the function of ribosomes (also known as ribosomal RNA) in protein synthesis? B. Serve as the coordinator mechanism to allow proper reading of the mRNA and

placement of the correct amino acid in the sequence by the tRNAs ____

6. A strand of recently transcribed mRNA contains the following components: intron (1), intron (2),

exon (3), intron (4), exon (5), exon (6), exon (7), intron (8). Which sequence is expected to appear in the mature mRNA? D. 3, 5, 6, 7 ____

7. Which process occurs outside of the nucleus? D. Translation of mRNA

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8. What would be the consequence for protein synthesis if only limited amounts of adenine were

available in a cell? C. Decreased production of cellular proteins ____

9. Which process would be directly inhibited by a lack of conversion of thymine to uracil? A. Translation

____ 10. What would be the sequence of RNA complementary to single-stranded DNA with the base

sequence of ACCTGAACGTCGCTA? C. UGGACUUGCAGCGAU ____ 11. Which events, structures, or processes are likely to trigger transcription of the beta-globin gene? A. Anemia and TATA boxes upstream from the beta-globin gene ____ 12. After a protein is synthesized during translation, what further process or processes is/are needed for

it to be fully functional? C. The protein first twists into a secondary structure and then “folds” into a specific tertiary structure for activation and function. ____ 13. How does an “anticodon” participate in protein synthesis? C. Ensuring the appropriate tRNA places the correct amino acid into the protein ____ 14. The protein glucagon contains 29 amino acids in its active linear form. What is the minimum

number of bases present in the mature messenger RNA for this protein? C. 87 ____ 15. Which feature or characteristic is most critical for protein function or activity? B. The sequence of amino acids ____ 16. How does a “codon” participate in protein synthesis? D. Indicating which amino acid is to be placed within the growing protein chain ____ 17. How does replacement of thymine with uracil in messenger RNA help in the process of protein

synthesis? A. Allowing messenger RNA to leave the nucleus ____ 18. How does the process of polyadenylation affect protein synthesis? D. Signaling the termination of mRNA translation ____ 19. Why are ribonucleases that digest mature messenger RNA a necessary part of protein synthesis? A. These enzymes prevent overexpression of critical proteins. Copyright © 2018 F. A. Davis Company

____ 20. Which statement about the introns within one gene is correct? D. The introns of one gene may be the exons of another gene. ____ 21. Which DNA segment deletion would cause a frameshift mutation? B. GAGTC ____ 22. A person who is worried that he may have inherited the gene mutation for Huntington disease is told

that he has the “wild-type” form of this gene. What is the best interpretation of this finding? C. His Huntington disease gene is considered normal. ____ 23. What is the expected result of a “nonsense” point mutation? C. Replacing an amino acid codon with a “stop” codon, resulting in a truncated

protein product ____ 24. What makes a frameshift mutational event more serious than a point mutational event? D. When the mutations occur in expressed genes, frameshift mutations always result

in disruption of the gene function, whereas a point mutation can be silent. ____ 25. What is the expected outcome when a person (twin A) experiences a large deletion of DNA in one of

his noncoding regions and his monozygotic twin (twin B) does not? A. DNA identification of each twin will be more specific. ____ 26. Which statement about single-nucleotide polymorphisms (SNPs) is true? D. SNPs are generally responsible for point mutations. ____ 27. Why are people who have poor DNA repair mechanisms at greater risk for cancer development? B. Their somatic mutations are more likely to be permanent. ____ 28. How does an acquired mutation in a somatic cell gene leading to cancer development affect a

person’s ability to pass on a predisposition for that cancer type to his or her children? B. There is no risk of passing on a cancer predisposition to one’s children from a somatic cell mutation. ____ 29. Which factor has the greatest influence on protein tertiary structure? C. Bond formation between amino acids that are distant from each other ____ 30. Jack and Jill go up a hill that has high levels of gamma radiation emission. Jack suffers 10 point

mutational events in a noncoding region, and Jill suffers only one frameshift mutation in the insulin gene–coding region of all her pancreatic beta cells. What are the possible and probable outcomes of these events for both people? C. Jack will have few, if any, effects on protein synthesis but will have more personal DNA markers; Jill will not produce any functional insulin and will have type 1 diabetes mellitus. ____ 31. A new experimental drug has been developed that reduces the activity of microRNA in the beta cells

of the pancreas of people with type 2 diabetes mellitus. If this drug was specific only for pancreatic beta cells, what would be its effect? A. Increased production of insulin

Chapter 3: Genetic Influence on Cell Division, Differentiation, and Gametogenesis ____

1. In what way is hypertrophic tissue growth more advantageous than hyperplastic tissue growth? Copyright © 2018 F. A. Davis Company

C. Less energy is required for hypertrophic growth. ____

2. In which phases of the cell cycle is the normal cell tetraploid (4N)? C. S and G2

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3. How is apoptosis related to physiologic homeostasis? B. The efficiency of organ/tissue functions is increased.

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4. Which normal cell characteristic is represented by the production of insulin in the beta cells of the

pancreas? A. Performance of a differentiated function ____

5. What is the consequence for a tissue/cell that no longer produces any cell adhesion molecules? D. Migration of cells into other tissues

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6. How do transcription factors influence cell division? B. Transcription factors regulate the expression of genes involved in cell division.

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7. How does apoptosis contribute to healthy organ and whole-body function? C. Removes old or damaged cells from an organ population

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8. What would be the expected response to a skin injury if the involved tissue had lost the normal cell

characteristic of contact inhibition? B. Excessive growth of replacement tissue ____

9. What is the function of a suppressor gene product? A. To ensure cell division occurs only when it is needed

____ 10. Normal cells spend most of their life spans in which phase? A. G0 ____ 11. How do cyclins influence the process of cell division? D. Opposing suppressor gene products and promoting cell division ____ 12. What is the general purpose of tyrosine kinase enzymes? A. Activating cyclins by phosphorylation ____ 13. Which event occurs during mitosis? C. Daughter cells are produced that are genetically identical to the parent cell. ____ 14. Which cell feature is common to normal human differentiated cells and to early embryonic human

cells? D. Euploidy ____ 15. Which feature or characteristic of early embryonic cells is unique in comparison with normal

differentiated cells? B. Pluripotency ____ 16. Which event characterizes embryonic commitment? C. Increased suppressor gene activity ____ 17. Which mechanism allows cell differentiation in embryonic tissue? C. Selected expression of individual structural genes

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____ 18. How many different genotypes are possible in any single mature spermatocyte of a man who is

heterozygous at a single gene locus for a specific trait? A. One ____ 19. Which stage of cell division is present in mitosis but is missing in meiosis? C. G2 ____ 20. What is the expected result when two homologous chromosomes fail to separate during meiosis I of

spermatogenesis? B. One gamete will have two of these chromosomes, and one will have neither of these chromosomes. ____ 21. During which phase of gametogenesis is the process of crossing over more likely to occur for either

spermatocytes or oocytes? D. Prophase I ____ 22. Which process is unique to spermatogenesis? B. Equal distribution of cytoplasm during meiosis I ____ 23. Which cell in the process of oogenesis has the most chromosomes? B. Primary oocyte ____ 24. What is the usual outcome of “crossing over” during meiosis I for both spermatogenesis and

oogenesis? B. Mixing of maternal and paternal genes within one chromosome pair ____ 25. Which cell division process sequences are normal for meiosis for gametogenesis? C. A single round of DNA synthesis followed by two separate rounds of meiotic cell

division ____ 26. Which response is the immediate and direct result of fertilization? C. Primary sex determination of the zygote ____ 27. What is the consequence of synapsis and crossing over? D. Random recombination of genetic material between paternal and maternal

chromatids ____ 28. Why is meiosis II for both spermatogenesis and oogenesis called an “equatorial division?” B. The actual number of chromosomes within the resulting cells is the same as before

this division. ____ 29. How many mature ovum result from the complete oogenesis of one oogonium? A. One ____ 30. Meiosis II of oocytes is completed at which developmental period? A. At the ninth prenatal week ____ 31. Why is normal fertilization of one mature ovum usually performed by only one mature sperm even

though hundreds of millions of sperm are present in the seminal fluid of one ejaculation? D. After being penetrated by one sperm, the ovum’s membrane changes electrically and prevents other sperm from entering. ____ 32. Why is fertilization of a polar body unlikely to lead to normal embryonic and fetal development?

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B. The lack of cytoplasm would inhibit cellular reproduction.

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Chapter 4: Patterns of Inheritance ____

1. Which factor allows inheritance patterns for a specific trait or health problem to be traced from one

family generation to another? B. Allele segregation ____

2. If there are 10 possible alleles for the single-gene trait of nose shape, how many alleles can a person

with euploid chromosomes inherit from his or her biological parents? B. 2 ____

3. An infant with type B blood is born to parents who both have type O blood. What genetic action or

phenomenon is responsible for this unusual blood type expression? A. Decreased penetrance of a dominant trait ____

4. Is it possible for two parents with achondroplasia to have a child who is of normal stature? A. Yes, because the disorder is autosomal dominant, and if both parents are

heterozygous, the child could inherit two normal stature gene alleles. ____

5. What is the risk for a person to inherit an autosomal-dominant genetic disease–causing allele from a

parent who is heterozygous if the disorder has a penetrance factor of 75%? C. 50% ____

6. Which statement reflects the criterion for autosomal-dominant transmission of single-gene traits? A. The risk for a person who is homozygous for the trait to transmit the trait to his or

her children is 100% with each pregnancy. ____

7. In which situation are phenotype and genotype always the same? C. Autosomal-recessive traits

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8. A girl of normal stature is born to two parents with achondroplasia who have very short stature,

especially disproportionately short arms and legs. What is the probability (by Punnett square analysis) that any pregnancy this girl eventually has will result in the birth of an infant with achondroplasia if her partner also has normal stature? D. Zero out of four (0%) ____

9. Which statement or factor is a criterion for autosomal-recessive transmission of single-gene traits? A. About 25% of the members of a large kindred with an autosomal-recessive trait

will express the trait. ____ 10. Which person is an obligate carrier of an autosomal-recessive single-gene trait or disorder without

expressing the trait or disorder? D. The daughter of a woman who expresses attached earlobes ____ 11. With which type of inheritance pattern does the trait or disorder usually first appear among siblings

rather than in parents of affected children? B. Autosomal recessive ____ 12. Which type of genetic transmission promotes the continued existence of genetic mutations in single

genes? B. Autosomal recessive ____ 13. On a five-generation pedigree, which feature distinguishes an X-linked-dominant disorder in which

males and females are equally affected from an autosomal-recessive pattern of inheritance? C. There are no instances of an affected father transmitting the disorder to his son. Copyright © 2018 F. A. Davis Company

____ 14. A woman whose father does not have hemophilia gives birth to a son with classic hemophilia. This

woman is found to have only 15% of the normal amount of clotting factor VIII (the clotting factor males with hemophilia are missing) and does have abnormal blood-clotting issues. Which phenomenon or factor is most likely responsible for her abnormal clotting factor expression? A. The X chromosome most commonly inactivated in her bone marrow is paternally derived. ____ 15. Which statement regarding inheritance of an autosomal-dominant gene allele with known variability

in expressivity is true? C. The degree of expressivity of a given autosomal-dominant trait with known variability cannot be predicted by analyzing parental expression. ____ 16. A man whose parents both have brown hair claims that his red beard was inherited from his maternal

uncle. Why is this claim incorrect? B. Genetic traits are transmitted in only a direct vertical direction. ____ 17. Mating of a yellow male parakeet with a blue female parakeet resulted in 18 offspring. Four (two

males; two females) had blue feathers, and 14 (eight females and six males) had yellow feathers. What allelic combinations and mode of inheritance can you determine from the evidence of the feather colors expressed? A. Yellow allele dominant; blue allele recessive; autosomal ____ 18. Mating of a female rabbit with a long tongue with a male rabbit that had a short tongue resulted in 12

offspring. Two had long tongues, two had short tongues, and eight had medium-length tongues. Which allele combinations explains the tongue lengths of the offspring? C. Short tongue dominant; long t...