Which diagram below best represents the chromatids if only crossing-over has occurred?

Cells destroy body cells infected by a virus or bacteria. killer t t memory t none of the above

Why do we perceive objects as retaining their brightness under different lighting levels?

Under the soviet system, the government a. controlled all forms of communication. b. allowed newspapers to print whatever they wanted. c. controlled editorials but not the reporting of news. d. encouraged access to a wide variety of news sources. select the best answer from the choices provided a b c d