51) The human genome codes for 20,000 to 25,000 proteins, : 1380821.
51) The human genome codes for 20,000 to 25,000 proteins, but any given cell might produce only 5,000 different proteins. How is this possible?
A) Every cell contains a different fraction of the genome.
B) All possible proteins are made in all cells, but those that are not needed are degraded.
C) Some cells use introns to produce proteins, and some cells use exons.
D) Genes are regulated so that not all genes are transcribed in all cells.
E) Not every cell has the machinery for transcription and translation.
52) Approximately what percent of the human genome codes for protein?
A) less than 2 percent
B) 97 percent
C) 75 percent
D) 12 percent
E) 21 percent
53) There are between 20,000 and 25,000 genes in the human genome, yet our cells are capable of producing more than 90,000 different proteins. How is this possible?
A) Many genes are actually yet to be discovered.
B) Introns are spliced back together to form mRNAs.
C) Micro-RNAs can also be used to make proteins.
D) Primary transcripts can be edited in different ways by alternative splicing to produce different mRNAs.
54) Which of the following is considered “non-coding” DNA?
A) rRNA genes
C) genes that are not constantly transcribed but may be turned on in some cells
55) Which of the following statements is correct?
A) The more complex the organism, the more DNA it has.
B) The simpler the organism, the less DNA it has.
C) The more complex the organism, the higher the percentage of the non-coding DNA.
D) The simpler the organism, the lower the percentage of the non-coding DNA.
56) How large is the human genome?
A) 3.2 billion base pairs
B) 10 billion base pairs
C) 1 million base pairs
D) 1 trillion base pairs
E) 3 million base pairs
57) The process by which genetic information in DNA is copied into RNA is called translation.
58) The first anticodon on a tRNA that binds to an mRNA transcript is complementary to AUG.
59) During translation, one mRNA can be translated by many ribosomes at once.
60) tRNA and rRNA are not translated into proteins.
61) The larger an organism is, the larger its genome must be.
62) Mutations in regulatory DNA sequences may be more important to evolution than mutations in genes.