28) Humans have 23 pairs of chromosomes, and chimps have 24 pairs of chromosomes. What is the most likely explanation for these differences in human and
... [Show More] chimp genomes?
A) The common ancestor of humans and chimps had 24 pairs of chromosomes. During human evolution, two human chromosomes fused end to end.
B) In the evolution of chimps, new adaptations resulted from additional chromosomal material.
C) At some point in evolution, human and chimp ancestors reproduced with each other.
D) Errors in mitosis resulted in an additional pair of chromosomes in chimps. Answer: A
Bloom's Taxonomy: Knowledge/Comprehension Section: 21.5
29) During which of the following processes does exon shuffling occur?
A) splicing of DNA
B) DNA replication
C) meiotic recombination
D) translation Answer: C
Bloom's Taxonomy: Knowledge/Comprehension Section: 21.5
30) When gene duplication occurs to its ultimate extent by doubling all genes in a genome, which of the following results has occurred?
A) pseudogene creation
B) creation of a gene cluster
C) creation of a polyploid
D) creation of a diploid Answer: C
Bloom's Taxonomy: Application/Analysis Section: 21.5
31) Which of the following types of genes or gene families may be created by mutations that occur in one member of a gene pair that arose from gene duplication?
A) only a pseudogene
B) only a gene with a new function
C) only a gene family with two distinct but related members
D) a pseudogene, a gene with a new function, and a gene family with two distinct but related members
Answer: D
Bloom's Taxonomy: Knowledge/Comprehension Section: 21.5
32) Based on the data in the Amino Acid Sequence Identity Table, which two members of the human globin gene family are the most divergent?
A) α1 and ß
B) Αγ and ß
C) α1 and a2
D) α1 and G?
Answer: D
Bloom's Taxonomy: Application/Analysis Section: 21.5
33) Fragments of DNA have been extracted from the remnants of extinct woolly mammoths, amplified, and sequenced. How can these fragments of DNA now be used?
A) to introduce certain mammoth traits into relatives, such as elephants
B) to clone live woolly mammoths
C) to understand the reasons why mammoths went extinct
D) to better understand the evolutionary relationships among members of related taxa Answer: D
Bloom's Taxonomy: Synthesis/Evaluation Section: 21.6
34) Homeotic genes contain a homeobox sequence that is highly conserved among very diverse species. The homeobox is the code for the domain of a protein that binds to DNA in a regulatory developmental process. Which of the following statements is therefore correct regarding homeotic genes?
A) Homeotic genes are selectively expressed as an organism develops.
B) Homeoboxes cannot be expressed in nonhomeotic genes.
C) Homeotic genes in apes and humans are very different.
D) All organisms must have homeotic genes. Answer: A
Bloom's Taxonomy: Synthesis/Evaluation Section: 21.6
35) A recent study compared the Homo sapiens genome with that of Neanderthals. The results of the study indicated that there was a mixing of the two genomes at some period in evolutionary history. Which of the following potential discoveries of additional data might be consistent with this hypothesis?
A) some Neanderthal sequences not found in living humans
B) a few modern H. sapiens with some Neanderthal sequences
C) duplications of several Neanderthal genes on a Neanderthal chromosome
D) some Neanderthal chromosomes that are shorter than their counterparts in living humans Answer: B
Bloom's Taxonomy: Synthesis/Evaluation Section: 21.6
36) Several of the different globin genes are expressed in humans, but at different times in development. Which of the listed mechanisms could allow for this?
A) exon shuffling
B) pseudogene activation
C) differential translation of mRNAs
D) differential gene regulation over time Answer: D
Bloom's Taxonomy: Synthesis/Evaluation Section: 21.6
37) Biologists now routinely test for homology between genes in different species. If genes are determined to be homologous, how are they related to each other?
A) by descent from a common ancestor
B) because of convergent evolution
C) by chance mutations
D) in function but not structure Answer: A
Bloom's Taxonomy: Application/Analysis Section: 21.6
38) A current view of how the human and chimpanzee can share most of their nucleotide sequences yet exhibit significant phenotypic differences is that many of the most important sequence differences alter .
A) structural genes
B) the number of repeated sequences
C) regulatory sequences
D) environmental factors Answer: C
Bloom's Taxonomy: Knowledge/Comprehension Section: 21.6
39) Studies in knockout mice have demonstrated an important role of the FOXP2 transcription factor in the development of vocalizations. Recent sequence comparisons of the FOXP2 gene in Neanderthals and modern humans show that while the DNA sequence may be different, the protein sequence it codes for is identical. Which of the following conclusions might logically be inferred from this information? [Show Less]