DNA Biology Practice Test

Unlock all questions

This demo includes only 20 questions. Upgrade to access hundreds of questions, flashcards, exam simulations, and disable ads.

Full question bankExam simulationsFlashcards
From $9.99Unlock all
Session length

1 / 20

A cell with three X chromosomes will contain ________.

0 Barr bodies

1 Barr body

2 Barr bodies

X-inactivation in mammals silences all but one X chromosome in female cells, turning the silenced X into a Barr body. Because only one X remains active, the number of Barr bodies equals the number of X chromosomes beyond that first active one. With three X chromosomes, two Xs become Barr bodies while one stays active, so the cell contains two Barr bodies.

3 Barr bodies

Next Question
Subscribe

Get the latest from Examzify

You can unsubscribe at any time. Read our privacy policy