chpt 26

Based on cladistics, which eukaryotic kingdom is polyphyletic and, therefore, unacceptable? A. Protista B. Plantae C. Fungi D. Animalia

A

Eukaryotes that are not closely related and that do not share many anatomical similarities can still be placed together on the same phylogenetic tree by comparing their ______. A. homologous genes that are highly conserved B. homologous genes that are poorly conserved C. mitochondrial genomes D. plasmids

A

Molecular clocks are based on the idea that _____. A. on average neutral mutations arise at a constant rate B. directional selection occurs at a constant rate C. advantageous mutations arise at a constant rate D. molecules resonate at a certain frequency that can be measured E. mutations occur once every generation

A

Suppose that two distantly related species live in similar environments and share a distinctive characteristic that facilitates survival in their environment but is not found in their immediate ancestors. Based on this information, this distinctive feature most likely represents A. an analogous character B. a character that spread from one species to the other by gene flow C. a homologous character D. a character that arose by genetic drift

A

The genome of an organism A. includes all of the organism's DNA B. only includes segments of the organism's DNA that do not encode proteins C. only includes the organism's genes D. of one species is identical to the genome of an organism of a closely related species

A

Which observation supports the position of eukaryotes at the convergence of the "ring of life"? A. The nuclear genome of eukaryotes contains genes from archaeans and from bacteria. B. Eukaryotes and archaeans both lack peptidoglycan in their cell walls. C. Circular chromosomes are present in both bacteria and archaeans. D. Only eukaryotes perform mitosis. E. Introns are rare in both bacteria and archaeans.

A

Which of the following items is most likely to form a simple linear relationship with the number of gene-duplication events? A. genome size B. phenotypic complexity C. number of cells/organism D. number of mitochondria

A

Which of the following statements about descent with modification is false? A. All similarities between organisms result from descent from a common ancestor. B. Any two species share some characteristics because they descended from a common ancestor that lived at some point in the past. C. Organisms that share a more recent common ancestor are likely to be more similar to one another than are organisms that share a distant common ancestor. D. Over time, evolution by natural selection causes organisms to accumulate differences from their ancestors

A

Which of the following statements about horizontal gene transfer is accurate? A. Horizontal gene transfer was quite common in the early stages of evolution of life on Earth. B. Horizontal gene transfer occurs only among closely related organisms. C. Horizontal gene transfer among organisms does not occur today. D. Horizontal gene transfer moves only genes that play a role in metabolism.

A

Which process occurred frequently in the early history of the three domains on Earth, and makes determining phylogenetic relationships of that time difficult? A. horizontal gene transfer B. alternative RNA splicing C. meiosis D. mitosis E. binary fission

A

A phylogenetic tree constructed using sequence differences in mitochondrial DNA would be most valid for discerning the evolutionary relatedness of _____. A. archaeans and bacteria B. chimpanzees and humans C. sharks and dolphins D. fungi and animals

B

Molecular clocks are more reliable when ________. A. most mutations of highly conserved DNA sequences should have no functional effect B. a significant proportion of mutations are not acted upon by natural selection C. the surrounding pH is close to 7.0 D. the DNA codes for amino acid sequences whose side groups (or R groups) have a neutral pH

B

The reason that paralogous genes can diverge from each other within the same gene pool, whereas orthologous genes diverge only after gene pools are isolated from each other, is that _____. A. having multiple copies of genes is essential for the occurrence of sympatric speciation in the wild B. having an extra copy of a gene permits modifications to the copy without loss of the original gene product C. polyploidy is a necessary precondition for the occurrence of sympatric speciation in the wild D. paralogous genes can occur only in diploid species; thus, they are absent from most prokaryotes

B

What kind of evidence has recently made it necessary to assign the prokaryotes to either of two different domains, rather than assigning all prokaryotes to the same kingdom? A. ecological B. rRNA genes C. mtDNA D. morphological

B

Which eukaryotic kingdom includes members that are the result of endosymbioses that included an ancient aerobic bacterium and an ancient cyanobacterium? A. Animalia B. Plantae C. Fungi D. Protista

B

The kingdom Monera was dismantled because of which of the following reasons? A. Some Monera contained nuclei in their cells. B. The Monera, as originally constituted, was monophyletic. C. Some, but not all, of the organisms in Monera contained DNA sequences that were similar to those of eukaryotes. D. The Monera, as originally constituted, contained both plants and animals

C

The most important feature that permits a gene to act as a molecular clock is _____. A. being acted upon by natural selection B. a recent origin by a gene-duplication event C. a reliable average rate of mutation D. a large number of base pairs

C

Which of the following statements is accurate, at least according to our present knowledge? A. Eukaryotes acquired nuclear genes only in the distant past; these genes can allow survival in anaerobic environments. B. Prokaryotes acquired genes from fungi; these genes can allow the digestion of cellulose. C. Genes from prokaryotes have been acquired by some eukaryotes; these genes can allow survival in extreme environments. D. Prokaryotes acquired genes from eukaryotes many times; these genes can allow survival in extreme environments.

C

The lakes of northern Minnesota are home to many similar species of damselflies of the genus Enallagma. These species have apparently undergone speciation from ancestral stock since the last glacial retreat about 10 thousand years ago. Sequencing which of the following would probably be most useful in sorting out evolutionary relationships among these closely related species? A. ribosomal RNA B. amino acid proteins C. conserved regions of nuclear DNA D. mitochondrial DNA

D

Which statement represents the best explanation for the observation that the nuclear DNA of wolves and domestic dogs has a very high degree of sequence homology? Dogs and wolves _____. A. belong to the same order B. have very similar morphologies C. are both members of the order Carnivora D. share a very recent common ancestor

D

Meaning of para-

alongside

Meaning of retro-

backward

Meaning of path-

disease

Meaning of oo- (or ov-)

egg

Meaning of pseudo-

false

Meaning of cephal-

head

Meaning of endo-

inside, inner

Meaning of bio-

life

Meaning of meso-

middle

Meaning of stoma

mouth

Meaning of ex-

out of

Meaning of ecto-

outside

Meaning of -phyte

plant

Meaning of deutero-

second

Meaning of sperm

seed

Meaning of derm

skin