Download BIOD210 Genetics Final Exam Questions and Answers- Portage Learning and more Exams Biology in PDF only on Docsity!
Question 1 The haploid number in human is ___, while the diploid number is ___. Answer: 23, 46 Question 2 Which of the following is correct? Sister chromatids are held together by cohesion. Chromosome bodies are responsible for the formation of spindle fibers. In metaphase, centromeres are dispersed throughout the nucleus. All are correct. Question 3 True or False: Genetic information can be transferred between bacteria on a single-stranded RNA molecule called a plasmid. False. Question 4 True or False: A chromosomal aberration is an alteration to the chromosome that results in a change to the total number of chromosomes, deletions or additions to the chromosome, or even complete rearrangement of chromosomal segments. True. Question 5 True or False: Most scientists believe that the biggest driver of a cancer phenotype is the ability of cancer cells to avoid apoptosis. False
Question 6 Explain briefly how the idea of epigenesis and preformation directly contradict each other. Preformation postulated that a fertilized egg contained a miniaturized version of a tiny human, called homunculus. Epigenesis directly contradicted that theory by stating that a fertilized egg undergoes a series of developmental events that eventually form a human. Question 7 Which of the following statements is correct? The X chromosome is much larger than the Y chromosome. The X and Y chromosomes share no homology. The X chromosome is the driving determinant for sex of an offspring. Incorrect segregation of X and Y chromosomes (for instance a female with XXX or X genotype) is always embryonic lethal. Question 8 The DNA in a ___ is packaged in the head, which is shaped like a capsule. The ___ of the phage pushes the DNA through the host cell membrane much like a syringe. Answer: phage, sheath Question 9 The only trisomy disorder in which individuals routinely live longer than one year is ___. The incidence of this disorder seems to increase with maternal ___. Down syndrome (or trisomy 21); age Down syndrome; health Cystic fibrosis; age
Inducible Question 14 The loss or gain of one chromosome, but not the set, is referred to as aneuploidy. The most common forms of aneuploidy are ___ (2n-1) and ___ (2n+1). Monosomy; trisomy Trisomy; monosomy Quaternomy; monosomy Monosomy, quaternomy Question 15 Explain how cancer cells control the extracellular matrix to drive the process of metastasis. Give an example of a protein we discussed that controls this in breast cancer cells. Answer: Metastatic cancer cells secrete large amounts of proteases that are responsible for digesting the extracellular matrix, which normally inhibits the migration of cells throughout the body. In addition to digesting the matrix, metastatic cells must also possess the ability to form secondary tumors in other areas of the body. These involve mutations in proteins that control structural integrity, cell adhesion, or proteolytic enzymes. Examples are metalloproteinase genes MMP1 and MMP2, which are present at very high levels in breast cancer tumors. Question 16 Consider 3 genes that assort independently in squirrels. A gene for brown color is dominant (D), a gene for a bushy tail is dominant (B), and a gene for reflux after eating acorns is recessive (a). Use the product law to predict the likelihood of producing a squirrel (from parents that are heterozygous for each trait individually) that is brown, bushy-tailed, and has reflux from all those acorns.
Answer: (3/4) x (3/4) x (1/4) = 9/64 probability of this squirrel being brown, bushy-tailed, and having reflux. Question 17 The genetic flow of material between organisms is NOT dependent on which of these criteria? Replication of the material Independent assortment of the genes Storage of the information Variation of DNA through mutation Question 18 Fill in the Blank: The ___ element is a ___ -acting element that is located upstream from the site of transcription initiation. Answer: Pribnow; cis Question 19 An intercalary deletion occurs ___ the chromosome, whereas a terminal deletion occurs at the ___ of the chromosome. At the start; end Within; end Within; start At the start; middle Question 20 Create a Punnett square to determine the characteristics of the F generation of the following cross: Both parents are heterogeneous for the dominant gene for a long, big toe (Tt). If they have four offspring, how many would you expect to have a long big toe?
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U Phe Phe Leu Leu Ser Ser Ser Ser Tyr Tyr Stop Stop Cys Cys Stop Trp
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C Leu Leu Leu Leu Pro Pro Pro Pro His His Gln Gln Arg Arg Arg Arg
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A Ile Ile Ile Met Thr Thr Thr Thr Asn Asn Lys Lys Ser Ser Arg Arg
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G Val Val Val Val Ala Ala Ala Ala Asp Asp Glu Glu Gly Gly Gly Gly
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What is the amino acid sequence of the two following codon sequences?
- 5’ – AUG GAG GCC GAU GAC UAG – 3’
- 3’ – GAU GCC GCA ACG GAA GUA – 5’ (Hint: make sure you read the right way) **Answer:
- Met-Glu-Ala-Asp-Asp-Stop
- Met-Lys-Ala-Thr-Pro-Stop This sequence needs to be read 5’ to 3’** Question 24 A dominant gene will always cause the expression of a dominant phenotype in the case of ___ dominance. Answer: Complete Question 25 True or False: The small subunit of the ribosome is responsible for recognition of the codon sequences as the mRNA from through the ribosome. It contains both the aminoacyl and the peptidyl sites.
Answer: False Question 26 True or False: In codominance, two alleles are fully expressed regardless of the sex of the organism. Answer: True Question 27 True or False: Transcription occurs on the coding strand. Answer: False.
