Many bacteria that are able to metabolize citrate produce negative results on this test. why

Adigestive system that is a series of tubes beginning at the mouth and ending at the anus is a digestive system.

The table shows dates and appearance of index fossils. which rock layers can be dated most precisely? a) a layer containing both a fossil 4 and a fossil 3 b) a layer containing both a fossil 2 and a fossil 3 c) a layer containing both a fossil 1 and a fossil 4 d) a layer containing both a fossil 1 and a fossil 2

Look at the photo of the leaf. which term best describes this leaf?