DNA Quiz
Questions: 16 · 10 minutes
1. Which set lists the three components of a DNA nucleotide?
Amino acid, phosphate group, and nitrogenous base
Ribose sugar, fatty acid, and nitrogenous base
Deoxyribose sugar, phosphate group, and nitrogenous base
Deoxyribose sugar, amino acid, and glycerol
2. During PCR, a sample is heated to separate the two strands of each DNA molecule. What interaction is primarily disrupted at this stage?
Peptide bonds between amino acids
Covalent bonds within the sugar-phosphate backbone
Hydrogen bonds between complementary bases
Bonds joining phosphate groups to PCR primers
3. One DNA strand has the sequence 5′-TACG-3′. Which sequence is complementary to it when written directly beneath it in the opposite direction?
3′-ATGC-5′
3′-UAGC-5′
3′-TACG-5′
3′-GCTA-5′
4. Ultraviolet radiation can cause abnormal links between neighboring thymine bases. Which cellular process can limit the lasting effect of this damage?
Translation of the damaged bases into lipids
Conversion of every thymine base into uracil
DNA repair that removes or corrects the damaged region
Immediate duplication of the damaged chromosome without checking it
5. In double-stranded DNA, which base normally pairs with cytosine?
Guanine
Thymine
Adenine
Uracil
6. Two DNA fragments are placed in the same gel electrophoresis lane. Under standard conditions, which fragment will usually travel farther through the gel?
The fragment with more adenine bases
The fragment with more guanine bases
The larger fragment
The smaller fragment
7. A new DNA variant arises in a cell. In which situation could the variant most directly be passed to a biological child?
It is present in an egg or sperm cell that contributes to conception
It occurs in a lung cell damaged by smoke
It occurs in a mature skin cell
It occurs in a red blood cell near the end of its lifespan
8. Two siblings with the same biological parents usually inherit different combinations of DNA. Which process contributes directly to this variation?
Independent assortment and recombination during meiosis
Replacement of DNA with RNA during fertilization
Removal of all recessive alleles before meiosis
Identical copying of all parental chromosomes into every gamete
9. A cell replicates one DNA molecule. Under the semiconservative model, what does each resulting DNA molecule contain?
Two newly synthesized strands
Two original strands joined to a new chromosome
One DNA strand and one RNA strand
One original strand and one newly synthesized strand
10. A mutation damages a gene's promoter without changing the protein-coding sequence. What is the most direct likely effect?
The chromosome will lose every gene after the promoter
Transcription of the gene may increase or decrease
The protein's amino acids will automatically be rearranged
DNA replication throughout the cell must stop
11. What does the abbreviation DNA stand for?
Dinucleic acid
Deoxyribonucleic acid
Deoxyribosomal acid
Dinitrogen acid
12. Investigators compare standard DNA profiles from identical twins. Why may these profiles fail to distinguish between the twins?
A person's DNA profile changes completely between tissues
Standard profiling measures blood type rather than DNA
Identical twins have DNA made from only two kinds of bases
Identical twins generally share the same inherited DNA markers used in standard profiling
13. A DNA base substitution changes a codon, but the new codon specifies the same amino acid. How is this mutation best described?
Frameshift mutation
Synonymous mutation
Nonsense mutation
Chromosome deletion
14. Which feature generally distinguishes RNA from DNA?
RNA contains phosphate groups, whereas DNA does not
RNA usually contains uracil where DNA contains thymine
RNA always forms a double helix, whereas DNA is single-stranded
RNA uses deoxyribose, whereas DNA uses ribose
15. A nerve cell and a skin cell from the same person contain nearly the same DNA but produce different sets of proteins. What best explains this difference?
Skin cells replace thymine with uracil
Each cell type uses a different genetic code
Different genes are active in the two cell types
Nerve cells lack chromosomes found in skin cells
16. Where is most of a bacterium's DNA typically located?
Inside a membrane-bound nucleus
Inside mitochondria
Within the cell wall
In the nucleoid region of the cytoplasm