Chapter 8 Learning and Memory

6) Muscle cells differ from nerve cells mainly because they _____. A) express different genes B) contain different genes C) use different genetic codes D) have unique ribosomes E) have different chromosomes

A) express different genes

2) The predominant mechanism driving cellular differentiation is the difference in gene _____. A) expression B) sequences C) order D) replication

A) expression

4) Mammals have a family of 500 and 1000 genes that encode receptor proteins on the surface of odor-receptor neurons. If all mammals have these genes, why do some mammals have a better sense of smell than others do? A) Some of the genes actively transcribing receptor proteins in some species are completely absent in other species. B) Some of the genes may have been mutated and rendered inactive in some species but not in others. C) Some species, particularly humans, rely much less on odor detection for survival; thus, the genes have mutated to encode proteins that aid in other senses, such as sight. D) Some species of mammals have a larger set of "basic odors" than other species.

B) Some of the genes may have been mutated and rendered inactive in some species but not in others.

9) Which of the following allows more than one type of protein to be produced from one gene? A) alternative forms of chromatin remodeling B) alternative forms of RNA splicing C) alternative forms of nucleosomes D) control of the frequency of translation initiation

B) alternative forms of RNA splicing

11) If you were to observe the activity of methylated DNA, you would expect it to _____. A) be replicating nearly continuously B) be unwinding in preparation for protein synthesis C) have turned off or slowed down the process of transcription D) be very actively transcribed and translated E) induce protein synthesis by not allowing repressors to bind to it

C) have turned off or slowed down the process of transcription

7) In a nucleosome, the DNA is wrapped around _____. A) polymerase molecules B) ribosomes C) histones D) a thymine dimer E) satellite DNA

C) histones

13) Two potential devices that eukaryotic cells use to regulate transcription are _____. A) DNA methylation and histone amplification. B) DNA amplification and histone methylation. C) DNA acetylation and methylation. D) DNA methylation and histone modification. E) histone amplification and DNA acetylation.

D) DNA methylation and histone modification.

8) Which method is utilized by eukaryotes to control their gene expression that is NOT used in bacteria? A) control of chromatin remodeling B) control of RNA splicing C) transcriptional control D) control of both RNA splicing and chromatin remodeling E) control of chromatin remodeling, RNA splicing, and transcription

D) control of both RNA splicing and chromatin remodeling

12) DNA methylation and histone acetylation are examples of _____. A) genetic mutation B) chromosomal rearrangements C) karyotypes D) epigenetic phenomena E) translocation

D) epigenetic phenomena

Cloning of plants from cuttings demonstrates that _____. A) an individual plant cell cannot de-differentiate and then redifferentiate B) differentiated plant cells may contain embryonic mRNAs C) plants lose genetic information in the differentiation process D) mature plant cells retain the full genetic information needed to carry out the developmental processes to produce a new individual plant

D) mature plant cells retain the full genetic information needed to carry out the developmental processes to produce a new individual plant

5) At the beginning of this century there was a general announcement regarding the sequencing of the human genome and the genomes of many other multicellular eukaryotes. Many people were surprised that the number of protein-coding sequences was much smaller than they had expected. Which of the following could account for much of the DNA that is not coding for proteins? A) most of the DNA serving as origins of DNA replication B) DNA that consists of histone coding sequences C) DNA that is translated directly without being transcribed D) non-protein-coding DNA that is transcribed into several kinds of small RNAs with biological function E) non-protein-coding DNA that serves as binding sites for reverse transcriptase

D) non-protein-coding DNA that is transcribed into several kinds of small RNAs with biological function

1) Which of the following statements about the DNA in one of your brain cells is true? A) Most of the DNA codes for protein. B) All of the genes of the genome are likely to be transcribed. C) Each gene lies immediately adjacent to an enhancer. D) Many genes are grouped into operon-like clusters. E) It is the same as the DNA in one of your heart cells.

E) It is the same as the DNA in one of your heart cells.

10) Several of the different globin genes are expressed in humans, but at different times in development. What mechanism could allow for this? A) exon shuffling B) intron activation C) pseudogene activation D) differential translation of mRNAs E) differential gene regulation over time

E) differential gene regulation over time