The excessive deforestation on the Christmas island crab would be the reduction of population or possibly extinction.
Answer:E. Adenine and Guanine
Explanation:
They are double <u>double carbon- nitrogen rings with four nitrogen atoms</u> bases found in DNA and RNA. Purines always pair with pyrimidines(cytosine and thymine) to form a double helix structure.This precise paring ensured that the DNA has a complementary structure.
This paring of purines with pyrimidines is by hydrogen bonds. This is to ensure easily unwinding during replication, that is formation of new DNA molecules.
purines bases are also used for cell protein synthesis fro cell division.
Addition polymerisation???
You can infer that the birds once had a common ancestor but became separated. Mutations in copying their genes stacked and caused changes in the beaks so the birds could be more well off or better adapted in their new environment.
Although "further disturbances" is pretty vague, both climate change and nonnative species will definitely have a potentially long term impact on an ecosystem
