Why do telomeres shorten each time DNA is replicated?

The two strands of DNA are “anti-parallel” (running in opposite directions). Which of the below is a necessary part of DNA replication due to the anti-parallel nature of DNA?

If the gene that encodes the sigma factor was deleted in an E. coli cell, what would be the most direct consequence?

Is the United States economy purely a market economy?  Explain in detail, citing specific aspects of the economy, why you agree or disagree.

Which is the nitrogenous base?

If the gene that encodes the sigma factor was deleted in an E. coli cell, what would be the most direct consequence?

Below are a parts of eukaryotic protein coding genes that are involved in transcription initiation. Match the DNA region to its description

Is the United States economy purely a market economy?  Explain in detail, citing specific aspects of the economy, why you agree or disagree.

Why are model organisms so useful in genetics research? 

What kind of bond connects the two strands of DNA to each other?