Adenine which is a purine base, always pairs with the pyrimidine Thymine in DNA and Uracil(also a pyrimidine) in RNA. The bond which is present between the two bases is a double hydrogen bond.
Guanine which is also a purine base, always pairs with the pyrimidine Cytosine, in the case of both, DNA and RNA. The bond which is present between the two bases is a triple hydrogen bond and hence, is stronger than the A-G double bond.
Answer:
1. C. Ecosystem
Explanation:
An ecosystem consist of living and nonliving things
6 images:
1 2
3 4
5 6
Interphase: image # 4
Prophase: image #6
Metaphase: #1
Anaphase: #3
Telophase: #2
Cytokinesis: #5