Biology

Giovani

25 June, 10:41

As described in your textbook, one way to determine if a segment of chromosomal DNA has been inserted into a vector is to put XGal in the growth media. Following overnight growth, some of the colonies are blue and some are white. Why are some colonies white? A. The white colonies contain a recircularized vector without an inserted fragment of chromosomal DNA. The lacZ gene has not been inactivated and XGal is broken down. B. The white colonies contain a vector with an inserted fragment of chromosomal DNA. The lacZ gene has not been inactivated and XGal is broken down. C. The white colonies contain a recircularized vector without an inserted fragment of chromosomal DNA. The lacZ gene has not been inactivated and XGal is not broken down. D. The white colonies contain a vector with an inserted fragment of chromosomal DNA. The lacZ gene has been inactivated and XGal is not broken down.