After Mendel's work, biologists determined that a single chromosome carries which of the following?

• A. Proteins that directly determine inheritance
• B. Multiple genes, each responsible for different traits
• C. Only one gene for a single trait
• D. Only non-coding DNA sequences

Answer: (B)

Verified step by step guidance

1. Recall Mendel's principle that traits are inherited through discrete units called genes, which are located on chromosomes.
2. Understand that chromosomes are long DNA molecules that contain many genes, not just one gene or a single type of sequence.
3. Recognize that each gene on a chromosome can be responsible for a different trait, meaning multiple genes are carried on a single chromosome.
4. Note that chromosomes also contain non-coding DNA sequences, but these do not directly determine inheritance of traits.
5. Conclude that a single chromosome carries multiple genes, each responsible for different traits, rather than only one gene or proteins.