Answer:
The five steps for determining density can be found in simple form as follows, measure the mass of the container, measure the volume of the liquid(s), measure the combined mass of the liquid and the container, and then determine the mass of the liquid alone and divide the mass by the volume of it.
69 i agree with her hope this helps
the answer is D. A magnesium atom donates two electrons to the fluorine atoms → Each fluorine atom accepts one of the electrons → The magnesium atom becomes a +2 ion → Each fluorine atom becomes a -1 ion
because magnesium only has 2 valence electrons, and it would be easier to lose electrons rather gain.
i just took the test, its right.
Answer: The lac Y and lac Z genes are turned off when lactose is present. Is a false statement about E coli and the lac operon. Therefore the correct option is A.
Explanation:
Escherichia coli is an enteric bacteria that makes use of lactose operon (or lac operon) for its lactose metabolism. The lac operon is made up of three genes which includes lacZ, lacY and Lac A. These genes are expressed only when lactose is present and glucose is absent. Also the lac repressor acts as a lactose sensor while the catabolite activation protein (CAP) acts as a glucose sensor. They help in turning on and off the genes with respect to lactose and glucose levels.
The lac Y and lac Z genes are turned off (not expressed) when glucose is present and lactose absent, but are expressed when glucose is absent and lactose present. Therefore option A is a false statement.