Answer:
A testable question is one that can be answered by designing and conducting an experiment. The answers to a testable question can be observed and measured. Hypothesis- a testable explanation of an observation. A hypothesis is NOT just an educated guess about what you think will happen.
Answer:
I would write "terrestrial/lives on land during all life stages" between the frog and pigeon branches.
Explanation:
Jaw evolution has started with fish, so i'd place that before the perch, evolution of four limbs is next and I would plate it between the perch and the frog. Evolution of an egg has ensured that organisms remain terrestrial during all stages of life and don't need to rely on water to lay their eggs. So I would place that between the frog and the pigeon. True mammary glands and true hair, as we know it formed on mammals so i'd place that between the pigeon and the rats (although synapsids evolved similar structures long before birds even existed). And lastly, I would place "walking on two legs" between rats and human branches. Because our ancestors evolved bipedalism relatively late.
Pretty sure it’s all of the above
Enzyme. An enzyme is a biological catalyst and is almost always a protein. It speeds up the rate of a specific chemical reaction in the cell.