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to RNA Transcription in the Ruby Track

Published at Jul 18 2018 · 0 comments
Test suite

Given a DNA strand, return its RNA complement (per RNA transcription).

Both DNA and RNA strands are a sequence of nucleotides.

The four nucleotides found in DNA are adenine (A), cytosine (C), guanine (G) and thymine (T).

The four nucleotides found in RNA are adenine (A), cytosine (C), guanine (G) and uracil (U).

Given a DNA strand, its transcribed RNA strand is formed by replacing each nucleotide with its complement:

  • G -> C
  • C -> G
  • T -> A
  • A -> U

For installation and learning resources, refer to the Ruby resources page.

For running the tests provided, you will need the Minitest gem. Open a terminal window and run the following command to install minitest:

gem install minitest

If you would like color output, you can require 'minitest/pride' in the test file, or note the alternative instruction, below, for running the test file.

Run the tests from the exercise directory using the following command:

ruby rna_transcription_test.rb

To include color from the command line:

ruby -r minitest/pride rna_transcription_test.rb


Hyperphysics http://hyperphysics.phy-astr.gsu.edu/hbase/Organic/transcription.html

Submitting Incomplete Solutions

It's possible to submit an incomplete solution so you can see how others have completed the exercise.


require 'minitest/autorun'
require_relative 'rna_transcription'

# Common test data version: 1.3.0 294c831
class RnaTranscriptionTest < Minitest::Test
  def test_empty_rna_sequence
    # skip
    assert_equal '', Complement.of_dna('')

  def test_rna_complement_of_cytosine_is_guanine
    assert_equal 'G', Complement.of_dna('C')

  def test_rna_complement_of_guanine_is_cytosine
    assert_equal 'C', Complement.of_dna('G')

  def test_rna_complement_of_thymine_is_adenine
    assert_equal 'A', Complement.of_dna('T')

  def test_rna_complement_of_adenine_is_uracil
    assert_equal 'U', Complement.of_dna('A')

  def test_rna_complement
    assert_equal 'UGCACCAGAAUU', Complement.of_dna('ACGTGGTCTTAA')
class Complement
  RNA = {
    'G' => 'C',
    'C' => 'G',
    'T' => 'A',
    'A' => 'U'

  def self.of_dna(dna)
    dna.chars.map { |char| RNA.fetch(char) { return '' } }.join

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