Answer:
Like the lac operon, the trp operon is a negative control mechanism. The lac operon responds to an inducer that causes the repressor to dissociate from the operator, derepressing the operon. The trp operon responds to a repressor protein that binds to two molecules of tryptophan.
Answer: The vascular plants are set apart in two main ways: Vascular plants have vascular tissues, which circulate resources through the plant. This feature allows vascular plants to grow to a larger size than non-vascular plants, which lack these specialized conducting tissues and are therefore restricted to relatively small sizes.
Answer:
For a limb to regenerate, you need bone, muscle, blood vessels and nerves. There are adult stem cells, a kind of undifferentiated cell that can become specialized, that regenerate muscle, but they don't seem to activate.
