Question

The template strand of DNA is read in the _________ direction to allow for synthesis of _______ in the __________ direction? How can cells with the exact same genome give rise to different cell types?

A) 3' to 5'; RNA; 3' to 5'; Epigenetic modifications
B) 5' to 3'; DNA; 5' to 3'; Splicing variations
C) 5' to 3'; RNA; 3' to 5'; Histone modifications
D) 3' to 5'; RNA; 5' to 3'; Transcription factor modifications

Answer 1

The correct answer is D) 3' to 5'; RNA; 5' to 3'; transcription factor modifications. The template strand of DNA is read in the 3' to 5' direction while synthesizing RNA in the 5' to 3' direction. Cell differentiation is possible through epigenetic modifications.

Step-by-step explanation:

The template strand of DNA is read in the 3' to 5' direction to allow for synthesis of RNA in the 5' to 3' direction. This is because DNA polymerase can only add nucleotides to the growing RNA strand in the 5' to 3' direction, following the rules of complementary base pairing. As for different cell types, despite cells having the exact same genome, different cell types can arise due to epigenetic modifications such as DNA methylation and histone modification, which affect gene expression without changing the underlying DNA sequence. These modifications are crucial for cellular differentiation and the development of different cell types within an organism.