Programming language

• Primary vs. Secondary Biological Databases:
• Primary (Archival) Databases: Store original, experimentally determined, direct sequence and structural submissions submitted directly by researchers.
• Examples: EMBL (European Molecular Biology Laboratory), GenBank (NCBI), DDBJ (DNA Data Bank of Japan), and PDB.
• Secondary (Derived) Databases: Store curated, processed, or value-added information derived from primary records:
• KEGG: Pathway and systems database.
• RefSeq: Curated, non-redundant reference sequence database.
• CATH: Protein domain classification database based on structural coordinates.
• Conclusion: The primary database is EMBL (Option 2).

Correct option: (2) EMBL

• Database Normalization and Modification Anomalies:
• In relational database design, unnormalized schemas suffer from severe update, insertion, and deletion anomalies due to data redundancy.
• Normal Forms (1NF, 2NF, 3NF, BCNF, 4NF, 5NF) decompose relations using functional and multivalued dependencies into progressively higher normal forms.
• This decomposition eliminates undesirable dependencies and prevents modification anomalies while preserving data integrity.
• Conclusion: Different classes of relations are created using Normal Forms (Option 4).

Correct option: (4) Normal Forms

• Referential Integrity Constraint Violations:
• Given $R_1(a, b, c)$ where $a$ is a foreign key referencing the primary key of $R_2(x, y, z)$:
• Insert into $R_1$: Inserting a tuple with a foreign key value $a$ that does not exist in $R_2$ causes a referential integrity violation.
• Insert into $R_2$: Inserting into the referenced relation never violates referential integrity.
• Delete from $R_1$: Deleting from the referencing relation removes a reference and never causes a violation.
• Delete from $R_2$: Deleting a primary key tuple from $R_2$ that is currently referenced by tuples in $R_1$ leaves dangling references and causes a referential integrity violation.
• Therefore, operations (d) and (a) can cause violations.
• Conclusion: Operations (d) and (a) will cause violations (Option 4).

Correct option: (4) Operations (d) and (a) will cause violations