Final answer:
Watson and Crick's experiments revealed that DNA has a double helix structure, complementary base pairing, and an anti-parallel arrangement.
Step-by-step explanation:
Watson and Crick made several major conclusions about the structure of DNA:
- Double helix structure: They proposed that DNA consists of two strands that are twisted around each other to form a right-handed helix.
- Complementary base pairing: They concluded that adenine (A) pairs with thymine (T), and guanine (G) pairs with cytosine (C) through hydrogen bonding.
- Anti-parallel arrangement: The experiments suggested that the two strands of DNA run in opposite directions, creating an anti-parallel arrangement.