The earths core is made up mainly of what 2 substances? 2. like an egg, earth has a core, a layer surrounding the core, and a thin, hard outer layer. which layers of the earth match the layers of an egg?

The two substances are rock (molten and solid) and metal (solid + liquid).

Layers of the earth from the outside in:

1. crust. hard rock/dirt/ground. Shell

2. mantle. melted rock and stuff. Egg white

3. core. Outer core - liquid. Inner core- solid. Nickle and iron. Yolk

I found the exercise on the internet. Attached is a picture of the statements and the bins.

Operon is not transcribed:
-trp operon: tryptophan present (tryptophan works as an inhibitor of the operon)
-lac operon: lactose absent (lactose works as the trigger for the operon)

Operon is transcribed but not sped up by positive control:
-trp operon: tryptophan absent (tryptophan works as an inhibitor of the operon, when absent the operon is active)
-lac operon: lactose present, glucose present (lactose works as the trigger for the operon, but when glucose is present, the operon activity remains only at basal level)

Operon is transcribed quickly by positive control:
-lac operon: lactose present, glucose absent (lactose works as the trigger for the operon, but when glucose is absent, the operon activity is at its maximum activity)