What must be true for two organisms to be considered the same species?

Hello!

Generally, what is considered must be true for two organisms to be considered the same species, is they have to be able to breed and produce offspring between each other.

If a species becomes separated, and over time cannot produce offspring with the other separated group, they are not the same species anymore.

Therefore, your answer is: They must be able to reproduce and produce offspring.

Hope this helped!

 C.  They can produce fertile offspring.

step 1 ammonium can be absorbed by plants, but some is converted into nitrates which are better for plants to absorb. this is called nitrification. 2. step 2 the deer eats the plants and uses the nitrogen-containing proteins for cell growth. 3. step 3 bacteria in the soil conduct nitrogen fixation to convert nitrogen gas from the atmosphere into ammonium. 4. step 4 some of the nitrates are absorbed back into plants, but denitrification breaks down the nitrates into nitrogen gas released back into the atmosphere. 5. step 5 nitrogen is found in the urine, which gets broken down into ammonium through the process of ammonification. 6. step 6 plants absorb the ammonium and begin assimilation, the process to add the nitrogen to protein.