Architectural differences between dynamic and static languages

Question

Are there any major architectural differences when designing applications that will be built on static languages (such as C# or Java) and dynamic languages (such as Ruby or Python)?

Which are the design possibilities that might be a good choice for one type that's a bad one for the other? Are there any useful features achievable with one type that's not with the other (in design and architecture, of course)?

Also, are there any dynamic-specific design patterns?