Review for SBI4U Strand 3 Test: Genetics
1. _____ XHY is the correct genotype for a male without hemophilia.
2. _____ Alternate forms of a gene are called alleles.
3. _____ A cross between a type A person and a type AB person can produce a type O offspring.
4. _____ Chargaff discovered that in terms of amounts of DNA nucleotides, A=C and T=G.
5. _____ Griffith used bacteriophages and discovered a "transforming factor".
6. _____ Radioactive phosphorus can be used to label DNA.
7. _____ Avery used protein-destroying enzymes to determine that protein is the genetic
8. _____ Watson and Crick used R-strain and S-strain bacteria to determine that DNA is in the
form of a double helix.
9. _____ The DNA backbone consists of sugars and phosphate groups.
10. _____ A free hydroxyl group is found on the 3' end of a DNA strand.
11. _____ A nitrogenous base is attached to a deoxyribose sugar.
12. _____ Carbons on deoxyribose are numbered in the counter-clockwise direction.
13. _____ Complementary DNA strands are antiparallel with the 3' end of one strand across from
the 5' end of the other strand.
14. _____ A cytosine on one strand binds to a guanine on the complementary strand by covalent bonds.
15. _____ If a DNA molecule contains 30% C, then it also contains 30% G.
16. _____ Watson and Crick made extensive use of x-ray diffraction pictures by Rosalind Franklin to deduce the structure of DNA.
17. _____ 3 bases in a row in DNA is called an anticodon.
18. _____ Each codon of mRNA codes for one amino acid.
19. _____ Transcription occurs in the cytoplasm of cells.
20. _____ Elongation is the 2nd stage of translation.
21. _____ During Initiation, the 1st tRNA binds to the P-site on a ribosome.
22. _____ Ribosomes are made of mRNA and protein.
23. _____ Ribosome are made of 3 subunits.
24. _____ During Elongation, amino acids are transferred from the tRNA at the A-site to the tRNA
at the P-site.
25. _____ Peptidyl transferase transfers amino acids from one tRNA to another and the amino
acids are joined by an ionic bond.
26. _____ During translation, the mRNA moves through the ribosome, 2 codons at a time.
27. _____ ATG is a possible mRNA codon.
28. _____ RNA is mostly in the form of a single helix.
29. _____ Ribose sugar contains an extra oxygen unlike deoxyribose sugar.
30. _____ DNA polymerase synthesizes new DNA strands in the 3' to 5' direction with respect to the
31. _____ Okazaki fragments are produced during discontinuous DNA replication.
32. _____ Gyrase enzyme joins Okazaki fragments together.
33. _____ DNA replication occurs in the nucleus of eukaryotic cells.
34. _____ A promoter sequence indicates where RNA polymerase should begin DNA replication.
35. _____ A stop codon does not code for any amino acid.
36. _____ Ribonuclease is the enzyme that degrades mRNA after translation.
37. _____ If a DNA triplet is ACG, the tRNA anticodon will be UGC.
38. _____ When the repressor protein in the lac operon binds, it overlaps the structural genes.
39. _____ In the lac operon, RNA polymerase binds to the operator.
40. _____ The 3 enzymes required by bacteria to metabolize lactose are called B-galactosidase,
acetylase, and polymerase.
41. _____ The lac operon illustrates eukaryotic gene control.
42. _____ Negative control of the lac operon is illustrated by binding of the cAMP-CAP complex to
43. _____ In the presence of glucose (but not lactose), the lac operon is turned OFF.
44. _____ Introns in DNA are transcribed to mRNA and then spliced out to produce mature mRNA.
45. _____ Post-translational modification may involve splicing of mRNA exons together.
46. _____ mRNA may be translated by more than one ribosome creating many copies of the final
protein or polypeptide.
47. _____ After translation, the completed protein is often inserted into the nucleus for transport to
48. _____ An "inversion mutation" is an example of a specific "point mutation".
49. _____ "Deletion mutations" lead to changes in the eventual "reading frame" of mRNA.
50. _____ All gene mutations are harmful.
51. _____ A "translocation mutation" occurs when a gene sequence breaks off of a chromosome and
is inserted backwards into the same chromosome.
52. _____ All cells in the body contain identical DNA molecules.
53. _____ DNA is negatively charged and is attracted to the positive terminal during gel
54. _____ Restriction enzymes cut DNA into fragments of different sizes called PCR fragments.
55. _____ The smallest DNA fragments travel furthest during gel electrophoresis.
56. _____ A radioactive label is applied to the DNA just before using restriction enzymes to cut
DNA into fragments.
57. _____ Bacterial plasmids are generally long, linear sequences of genes.
58. _____ Recombinant DNA is made by inserting a gene into a bacterial plasmid.
59. _____ "Tt" represents a heterozygous phenotype.
60. _____ Restriction enzymes always cut DNA at palindromes and produce "sticky ends".
61. _____ Humans have created many new species of organisms through natural selection.
62. _____ When the Trp operon is ON, it leads to the production of tryptophan-degrading enzymes.
63. _____ The Trp repressor is unable to bind to the operator in the absence of tryptophan.
64. _____ ddATP, ddGTP, ddCTP, and ddTTP lack an -OH group on the deoxyribose 3' carbon.
65. _____ Addition of a dideoxy nucleotide causes "chain termination" during DNA replication.
66. _____ The probability of a particular 7-base-pair sequence occuring in DNA is 1/47.
67. _____ For a DNA gel prepared by the Sanger Method, the DNA sequence is read from the bottom to top (smallest to largest fragment). The actual sequence of the DNA is the complement to the sequence read.
68. _____ Restriction enzymes are named after the virus from which it originated.
69. _____ EcoRI comes from eschericia Coli and produces "blunt ends".
70. _____ In chromosomes, DNA is coiled around "histones", pos. charged proteins that bind/stabilize neg. charged DNA.