Final answer:
When chromatin is in a closed configuration, nucleosomes are tightly packed, making it difficult for transcription factors to access DNA and initiate transcription.
Step-by-step explanation:
If chromatin is in a closed conformation, nucleosome position and histone composition make it difficult for transcription factors to gain access to and bind their target sequences in the promoter DNA.
This is because the nucleosomes are positioned closely together, causing the DNA to be less accessible, hence, impeding the DNA from becoming single-stranded during transcription, which is necessary for transcription to occur.