Eukaryotic Cells Chapter 9

22. In comparing the genomes of mammals to the relatively small genome of the puffer fish, what is missing in the puffer fish? A) Genes B) Repetitive DNA in noncoding sequences C) Introns D) Exons

B) Repetitive DNA in noncoding sequences

19. For organisms that are closely related, which of the following often provides the most information about how long ago the two species diverged from each other? A) Changes in conserved genes B) Selectively neutral changes to DNA C) The number of gene duplication events D) The total number of chromosomes

B) Selectively neutral changes to DNA

23. The nucleotide sequences of which of the following genes have been used to create a single all encompassing tree of life? A) Globin genes B) Small subunit rRNA genes C) Myosin genes D) Immunoglobulin genes

B) Small subunit rRNA genes

21. If two distantly related organisms have regions of conserved synteny, what does this mean? A) The genes examined in the two species are present in the same order as in their most recent common ancestor B) The genes examined in the two species are identical in sequence to each other C) The genes examined in the two species are on different chromosomes, but in their last common ancestor, the genes were on the same chromosome

B) The genes examined in the two species are identical in sequence to each other

16. Homologs of many human genes are easy to detect in such organisms as worms, fruit flies, yeasts and even bacteria. True False

True

2. In sexually reproducing organisms, only changes to the germ line are passed along to progeny. True False

True

24. The human genome contains 3.2 billion base pairs divided among 22 autosomes and 2 sex chromosomes. True False

True

4. Most often single nucleotide mutations have no effect on the appearance or viability of an organism True False

True

8. Almost every gene in the genomes of vertebrates exists in multiple versions. True False

True

3. What is the term for a name change in a single nucleotide pair? A) Frameshift mutation B) Point mutation C) Nonsense mutation D) Adaptive mutation

B) Point mutation

25. Which of the following is true about the human genome? A) About half the human genome consists of mobile genetic elements B) About half the human genome consists of genes coding for proteins C) About half the human genome consists of introns

A) About half the human genome consists of mobile genetic elements

7. Point mutations can be caused by an error in what process? A) DNA replication and repair B) Homologous recombination C) Transcription D) Replication of chromosome ends

A) DNA replication and repair

30. The differences due to mutation that accumulate in two difference DNA sequences derived from a common ancestral sequence is referred to as: A) Divergence B) Purifying selection C) Natural selection D) Conserved synteny

A) Divergence

15. What are homologous genes? A) Genes that are similar in the nucleotide sequence because of a common ancestry B) Genes that encode proteins that perform similar functions C) Genes that encode proteins that fold into the same shape

A) Genes that are similar in the nucleotide sequence because of a common ancestry

28. Most of the genetic variation in the human genome takes what form? A) Single nucleotide polymorphisms B) DNA duplications and deletions C) Chromosomal rearrangements

A) Single nucleotide polymorphisms

9. In Eukaryotes, individual protein domains are generally encoded by single ________. A) exons B) introns C) genes D) inverted repleats

A) exons

10. Which structures in eukaryotic genes are thought to have facilitated the ability to duplicate a protein domain of a gene without damaging it in the recombination process? A) introns B) exons C) promoters D) regulatory elements

A) introns

17. Evolution occurs through: A) mutation followed by natural selection B) adaptation followed by mutation C) selection followed by mutation D) translation followed by natural selection

A) mutation followed by natural selection

27. Humans differ from one another by how much? A) 1% B) 0.1% C) 0.01% D) 0.001%

B) 0.1%

26. Approximately how many genes are in the human genome? A) 13,000 B) 25,000 C) 100,000 D) 3.2 billion

B) 25,000

14. IN the present day organisms, which trait or gene is commonly acquired by horizontal gene transfer? A) lactose tolerance B) Drug resistance C) Sickle cell anemia D) Halitosis

B) Drug resistance

11. Which of the following is NOT true? A) Exon shuffling allows the generation of hybrid proteins with new functions B) Exon shuffling allows bacteria to become antibiotic resistant C) All human proteins are thought to have arisen from the duplication and shuffling of a few thousand exons D) Exon shuffling requires the presence of introns

B) Exon shuffling allows bacteria to become antibiotic resistant

6. It is thought that gene duplications are generated by an error in what process? A) DNA replication and repair B) Homologous recombination C) Transcription D) Replication of chromosome ends

B) Homologous recombination

5. In our human ancestors, the enzyme lactase, which allows us to digest the milk sugar lactose, was produced only during infancy. Today a portion of the adult population can digest lactose while other adults remain lactose intolerant. Which adults have point mutations in the regulatory DNA of their lactase gene? A) Those who are lactose intolerant B) Those who able to digest lactose

B) Those who able to digest lactose

29. Comparing genome sequences of different species: A) demonstrates that humans share only a small number of genes with non-mammal organisms B) provides a powerful way to identify genes and their regulatory sequences C) reveals the important role SNPs play in causing diseases D) reveals that surprisingly humans are more closely related to chickens that to chinchillas

B) provides a powerful way to identify genes and their regulatory sequences

18. Which of the following types of genes would be most likely to accumulate changes to its sequence? A) A gene that codes for a highly optimized essential protein or RNA molecule B) A gene that is highly conserved among a wide diversity of organisms C) A gene that has recently been duplicated in the genome D) A gene that is one the Y chromosome

C) A gene that has recently been duplicated in the genome

1. Which of the following is NOT a mechanism of genetic variation? A) Mutation within the coding sequence of a gene B) Mutation within regulatory DNA of a gene C) Purifying selection D) Gene Duplication and Divergence E) Exon Shuffling

C) Purifying selection

12. Which is not true of mobile genetic elements (MGEs)? A) MGEs can serve as targets of homologous recombination, resulting in DNA duplication and deletion B) MGEs can disrupt a gene's coding sequences but not its expression level C) MGEs can occasionally rearrange neighboring DNA sequences of the host genome, moving exons from one position to another D) MGEs are present in bacteria as well as eukaryotes

D) MGEs are present in bacteria as well as eukaryotes

13. Horizontal gene transfer is common in both eukaryotes and prokaryotes True False

False

20. Humans and chimpanzees are so closely related that it is impossible to reconstruct the gene sequence of the extinct common ancestor of the two species. True False

False