The answer to the question is letter d
Answer:
Through this experiment we study the process of photosynthesis.
• In the begining the leaf disks's tissue has oxygen, this allows them to float.
• Then, in the experiment we infiltrate the leaf disks with a solution that has bicarbonate, and as a result their density changes (it increases) and so the leaf disks sink.
• Once the disks are on the bottom and we direct the light to them the process of photosynthesis starts, being the bicarbonate the source of carbon for the process.
• As we know a product of the photosynthesis proces is oxygen, so when it is released into the leaf disks the overall density changes again and the disks rise.
So as we can see, in this experiment the purpose of the bicarbonate is being the source of carbon for the process of photosynthesis that occurs in the leaf disks.
Answer:
Your answer is probably A). If you find a fossil of an armored fish in layer A, and you find a fossil of a trilobite in layer B (five layers deeper), then you can safely assume that the trilobite is older than the armored fish.
Answer:
seed cones and pollen cones
Explanation:
In gymnosperms, their reproductive structures include the pollen cones, which produce pollen grains or the male gametophyte; and the seed cones, which produce female gametophyte.