question

1) The term "gene expression" refers to the

answer

D) process by which genetic information flows from genes to proteins.

question

2) A gene operon consists of

answer

D) transcribed genes, an operator, and a promoter.

question

3) In a prokaryote, a group of genes with related functions, along with their associated control sequences, defines

answer

A) an operon.

question

4) The lac operon in E. coli

answer

C) prevents lactose-utilizing enzymes from being expressed when lactose is absent from the environment.

question

5) Proteins that bind to DNA and turn on operons by making it easier for RNA polymerase to bind to a promoter are called

answer

D) activators.

question

6) The lac operon of E. coli is ________ when the repressor is bound to lactose.

answer

A) active

question

7) The expression of the tryptophan operon is controlled by

answer

D) a repressor that is active when it binds to tryptophan.

question

8) Which of the following is likely to occur in E. coli cells that are grown in skim milk?

answer

D) The trp repressor is activated and the cells will produce lactose-utilizing enzymes.

question

9) A single cell, the zygote, can develop into an entirely new organism with many different specialized cells. Which of the following statements about this process is false?

answer

B) Additional genetic information for the formation of specialized cells is passed on to the developing embryo via the placenta.

question

10) The basis of cellular differentiation is

answer

A) selective gene expression.

question

11) The genes for the enzymes of glycolysis

answer

A) are active in all metabolizing cells, but the genes for specialized proteins are expressed only in particular cell types.

question

12) Which of the following statements regarding DNA packing is false?

answer

C) DNA packing tends to promote gene expression.

question

13) The relationship between DNA and chromosomes is most like

answer

B) thread wrapped around a spool.

question

14) In female mammals, the inactive X chromosome in each cell

answer

B) becomes a Barr body.

question

15) The tortoiseshell pattern on a cat

answer

B) results from X chromosome inactivation.

question

16) Both prokaryotic and eukaryotic cells use ________ to turn certain genes on or off.

answer

D) proteins

question

17) Enhancers are

answer

A) DNA sequences to which activator proteins bind.

question

18) Silencers

answer

C) bind to DNA sequences and inhibit the start of transcription.

question

19) RNA splicing involves the

answer

A) removal of introns from the molecule.

question

20) The coding regions of a gene (the portions that are expressed as polypeptide sequences) are called

answer

B) exons.

question

21) Which of the following permits a single gene to code for more than one polypeptide?

answer

C) alternative RNA splicing

question

22) Small pieces of RNA that can regulate translation of mRNA are called

answer

B) microRNA.

question

23) miRNA can be used by

answer

B) cells to prevent infections from double-stranded RNA viruses.

question

24) All of the following mechanisms are used to regulate protein production except

answer

C) DNA editing.

question

25) Which of the following mechanisms of controlling gene expression occurs outside of the nucleus?

answer

D) translation

question

26) Which of the following statements about fruit fly development is false?

answer

D) The location of the head and tail ends of the egg is primarily determined by the location of sperm entry during fertilization.

question

27) A homeotic gene

answer

A) serves as a master control gene that functions during embryonic development by controlling the developmental fate of groups of cells.

question

28) Which of the following statements about microarrays is false?

answer

A) Microarrays use tiny portions of double-stranded RNA fragments from a large number of genes.

question

29) In multicellular organisms, the coordination of cellular activities relies on

answer

A) cell-to-cell signaling and signal transduction pathways.

question

30) To initiate a signal transduction pathway, a signal binds to a receptor protein usually located in the

answer

C) plasma membrane.

question

31) Transcription factors attach to

answer

D) DNA.

question

32) A signal outside a cell triggers changes in the transcription and translation inside the cell through

answer

B) signal transduction pathways.

question

33) Yeast are able to communicate with each other

answer

B) through chemical signaling.

question

34) Signal transduction pathways

answer

A) are mechanisms of communication that probably evolved in ancient prokaryotes.

question

35) In plants, most differentiated cells retain

answer

C) a complete set of their genes, and retain the ability to express those genes under certain circumstances.

question

36) Why can some plants be cloned from a single cell?

answer

D) Plant cells can dedifferentiate and give rise to all of the specialized cells required to produce an entire plant.

question

37) Which of the following processes occurs when a salamander regenerates a lost limb?

answer

A) Certain cells in the limb dedifferentiate, divide, and then redifferentiate to form a new limb.

question

38) The cloning of Dolly the sheep

answer

D) demonstrated that the nuclei from differentiated mammalian cells can retain their full genetic potential.

question

39) The use of cloning to produce special embryonic stem cells is called

answer

B) therapeutic cloning.

question

40) Which of the following mammals has not yet been cloned and brought through the complete gestation cycle?

answer

A) human

question

41) Which of the following possible uses of reproductive cloning is still considered by most to be an unresolved ethical issue?

answer

A) the reproductive cloning of humans

question

42) Which of the following statements regarding stem cells is false?

answer

B) Adult, but not embryonic, stem cells can be grown in laboratory culture.

question

43) Adult stem cells have limited therapeutic potential

answer

B) because their developmental potential is limited to certain tissues.

question

44) A gene that can cause cancer when present in a single copy in a cell is called a(n)

answer

A) oncogene.

question

45) Which of the following statements about proto-oncogenes is false?

answer

B) A mutation in a tumor-suppressor gene can stop cell division immediately.

question

46) Which of the following is not a factor that contributes to normal cells becoming cancerous?

answer

D) one or more of the cell's genes being removed by a virus

question

47) Cancer of the colon is caused by

answer

D) several somatic cell mutations.

question

48) The development of colon cancer occurs slowly, and colon cancer is more frequently seen in the elderly than the young. This is most likely because

answer

C) four or more somatic mutations must occur to give rise to the cancer, which takes time.

question

49) Mutations in the proto-oncogene ras and the tumor suppressor gene p53

answer

B) disrupt normal regulation of the cell cycle.

question

50) Mutations in the p53 gene can lead to cancer by

answer

A) causing the production of a faulty protein that is no longer able to inhibit cell division.

question

51) The carcinogen known to cause the most cases and types of cancer is

answer

A) tobacco.

question

52) Which of the following statements regarding cancer risk factors is false?

answer

D) Mutagens are usually not carcinogens.

question

53) In this drawing of the lac operon, which molecule is an inactive repressor?

answer

D) molecule D

question

54) Which structure in this figure shows one complete nucleosome?

answer

D) structure D

question

55) Why don't the grafted hybrids produce apples with a blend of traits from the scion and the rootstock?

answer

D) The rootstock regulates gene expression in the scion, but contributes no genetic information for fruit production.

question

56) Half the trees in an orchard were derived from rootstock "A" and half from rootstock "B," but all the trees had the same scion. If the trees grafted onto rootstock "A" were infected by a parasite that causes blossom rot, the trees grafted onto rootstock B

answer

A) would be very likely to become infected, because the remaining scions are genetically identical to those that are already infected.

question

mRNA can be used by

answer

Cells to prevent infections from double-stranded RNA viruses.

Biology Chapter 11 – Flashcards

Unlock all answers in this set

Haven't found what you were looking for?

Search for samples, answers to your questions and flashcards