SwipeExam Get the app

DNA base pairing

  • ATI TEAS
  • Science: Biology
  • Multiple choice
  • Difficulty 3 of 5

Question

A student builds a double-stranded DNA model and places cytosine on one strand. Which base belongs opposite it?

  1. Guanine✓ Correct

    Guanine is the complementary partner for cytosine.

  2. Adenine✗ Incorrect

    Adenine pairs with thymine instead.

  3. Thymine✗ Incorrect

    Thymine pairs with adenine instead.

  4. Cytosine✗ Incorrect

    Cytosine pairs with guanine, not another cytosine.

Answer

A. Guanine

Rationale

Complementary pairing determines the opposite base in the model. Cytosine and guanine belong together, while adenine matches thymine.

RememberIn DNA, C pairs with G and A pairs with T.

Sources

  • ​Base Pair National Human Genome Research Institute (NIH) · License: US government work (public domain) · Retrieved · Definition

Last verified: 2 independent automated checks Question teas-sb-00192, version 1

Checks are automated. No licensed clinician has reviewed this question. Check the sources and your program’s materials.

Report an error in this question. For education only; not medical advice. See all sources and licenses.

More ATI TEAS sample questions