Timedora
Free Practice Quiz Question List

3 Biological Sequence Data Online Quiz Questions

Use this free practice quiz with 20 questions to review 3 Biological Sequence Data, test your knowledge, and prepare for your next test or exam.

20 questions
01
Choose one
1 point

A sequencing-read file has records with an identifier, a sequence, a plus line, and a quality string. Which format best matches this structure?

  1. A

    A header, a sequence, and a quality string

  2. B

    An identifier, a sequence, a plus line, and a quality string

  3. C

    A sequence, an annotation block, and a reference list

  4. D

    A header and a sequence, with one quality score stored in the header

02
Choose one
1 point

A downstream analysis still needs the base-call quality scores for sequencing reads. Which format should you retain rather than converting the reads to a sequence-only format?

  1. A

    FASTA

  2. B

    GenBank

  3. C

    FASTQ

  4. D

    EMBL/ENA

03
Choose one
1 point

A DNA sequence contains the symbol N at one position. What does N indicate in this context?

  1. A

    Any nucleotide

  2. B

    A protein residue that is always a stop

  3. C

    A nucleotide that must be removed before analysis

  4. D

    A fixed substitution for thymine

04
True or false
1 point

In commonly used Phred-scaled FASTQ quality scores, a higher score indicates a lower estimated probability that the base call is incorrect.

  1. A

    True

  2. B

    False

05
True or false
1 point

It is good practice to replace every U with T in RNA data during preparation, even when the intended analysis does not require DNA-style notation.

  1. A

    True

  2. B

    False

06
Fill in the blank
1 point

In a nucleotide sequence, N means .

07
Fill in the blank
1 point

Some protein records use to represent an unknown residue.

08
Written response
1 point

Which sequence format is commonly used for sequencing reads and stores per-base quality scores?

09
Written response
1 point

How many lines are in each FASTQ record?

10
Written response
1 point

Name one annotated sequence-record format that can include organism, feature, and reference information alongside the sequence.

11
Choose all
1 point

You are preparing sequence data for analysis. Select all checks supported as part of a careful preparation workflow.

  1. A

    Check that the file format and sequence alphabet are suitable for the intended tool.

  2. B

    Replace every ambiguity symbol automatically before checking the tool's accepted alphabet.

  3. C

    Check that records are complete and identifiers are preserved.

  4. D

    Convert FASTQ to FASTA immediately so quality information cannot affect downstream work.

  5. E

    Screen for possible contamination or adapter sequence when appropriate.

12
Choose all
1 point

Select all statements that correctly describe when annotated record formats or FASTA may be useful.

  1. A

    Annotated records can include organism, features, and references alongside sequence.

  2. B

    FASTA always includes per-base sequencing quality scores.

  3. C

    FASTA is often more convenient when a tool needs sequence alone.

  4. D

    Annotated formats must be converted to FASTQ to preserve their annotations.

13
Choose one
1 point

When interpreting a FASTA record, which part of the header is commonly used as the sequence identifier?

  1. A

    The last word in the header is always the identifier.

  2. B

    The first word in the header is commonly used as the sequence identifier.

  3. C

    The first nucleotide after the header is the identifier.

  4. D

    The identifier is stored as a per-base quality score.

14
Choose one
1 point

A historical FASTQ file will be processed by software that expects a particular quality-score encoding. What should you do before analysis?

  1. A

    Assume every FASTQ file uses the same quality encoding.

  2. B

    Convert all quality strings to sequence letters before analysis.

  3. C

    Confirm the quality-score encoding expected by the software.

  4. D

    Remove all quality strings because they cannot be interpreted.

15
Open ended
1 point

A sequencing project has raw reads with base-call quality scores, and a later analysis may still need those scores. Describe how you would preserve and assess the reads before preparing them for the next tool. Include the risk of converting formats and how you would handle trimming or filtering.

16
Choose one
1 point

A nucleotide sequence contains N at one position. Which interpretation is supported by this symbol?

  1. A

    The position may contain any nucleotide.

  2. B

    The position is definitely adenine.

  3. C

    The position marks a sequencing quality score.

  4. D

    The sequence ends at this position.

17
Choose one
1 point

A FASTA record begins with the header >sample1 example DNA sequence. Using the common FASTA convention, which part is the sequence identifier?

  1. A

    example

  2. B

    sample1

  3. C

    ACGTTGCA

  4. D

    The entire header, including the > character

18
True or false
1 point

True or false: A coding sequence can be treated as the same biological region as a full transcript when verifying sequence type.

  1. A

    True

  2. B

    False

19
Choose one
1 point

You need a sequence record that also carries organism information, feature annotations, and references. Which format choice best fits that need?

  1. A

    FASTA, because it stores the sequence and its per-base quality scores

  2. B

    FASTQ, because its four-line records provide organism annotations and references

  3. C

    GenBank or EMBL/ENA, because these formats can include sequence annotations and references

  4. D

    A plain sequence string, because it preserves all record context

20
Written response
1 point

For Phred-scaled quality scores, if a base has a higher score, does its estimated probability of an incorrect call rise or fall? Enter one verb.