Starch is digested by the enzyme amylase. A student did an investigation on amylase activity.
This is the method used.
1. Mix amylase solution and starch suspension at 20 °C in a boiling tube.
2. Remove a drop of the mixture every 30 seconds and test it for starch.
3. Continue testing every 30 seconds until no starch is detected.
4. Repeat the investigation at different temperatures.
0 1 . 1 What apparatus should the student use to control the temperature of the mixture?

The images show two species of tree frogs in a particular region. the gray tree frogs are adapted to the trees of the woodlands, while the green tree frogs can survive in woodlands or grasslands. the gray frog was abundant in the woodlands. because of climatic changes, most of the trees in the region died, and the woodlands changed to grasslands. in such a case, the . the gray tree frog is closely related to the green tree frog genetically, but they have different mating calls. this suggests that speciation occurred because of .