Question

although nearly all cells in a multicellular organism contain the same dna, not every gene in every cell is transcribed into mrna. transcription, and the rate at which it occurs, is carefully regulated so only proteins needed by a cell are produced at any given moment.
transcription can be regulated in a variety of ways. sometimes, chromosomes are wrapped around histone proteins such that only certain genes are physically accessible to transcription enzymes. other times, special proteins called transcription factors bind to specific dna sequences to either activate or block a genes transcription.
select the true statements.

• transcription can be regulated by histone proteins and transcription factors.
• each of an organisms cells contains unique dna.
• not every gene in a cells dna is transcribed.
• all cells in a multicellular organism produce the same proteins.

Explanation:

1. The passage states transcription is regulated by histone proteins (controlling physical access to genes) and transcription factors (activating/blocking transcription), so this statement is true.
2. The first sentence clarifies nearly all cells in a multicellular organism have the same DNA, so this statement is false.
3. The first sentence explicitly says "not every gene in every cell is transcribed into mRNA", so this statement is true.
4. The passage notes transcription is regulated to produce only proteins a cell needs, so cells do not produce the same proteins, making this statement false.

Answer:

• Transcription can be regulated by histone proteins and transcription factors.
• Not every gene in a cell's DNA is transcribed.