NCEA Bio 2.7 Gene Expression -Transcription

What is the DNA base paring rules ?

• G binds with T, C binds with A

• T binds with C, A binds with G

• A binds with U, C binds with G

• A binds with T, C binds with G

How do the RNA base pairing rules differ from the DNA base pair rules ?

• In RNA base pairing , U replaces T.

• In RNA base pairing, there is no C and G

• In RNA base pairing, A replaces T

• There is no difference

Answer explanation

Which of the following is the best definition of a template strand?

• The strand of DNA that is exact copy of mRNA

• The strand of mRNA that is produced.

• The strand of RNA that forms ribosomes.

• The strand of DNA that is used to form mRNA.

Answer explanation

The template strand is one of the strands of DNA that is used as a template to form mRNA during transcription.

What is the final product of transcription?

• Protein

• mRNA

• DNA

• tRNA

Answer explanation

mRNA is the final product of transcription. When transcription is complete, the mRNA moves out of the nucleus and into the cytoplasm.

Would a cell be able to successfully carry out protein synthesis without transcription? Select the option that best describes your answer

• DNA could still leave the nucleus and move to ribosome, where translation takes place.

• Without transcription, tRNA would not be produced, which is essential for protein synthesis.

• Without transcription, mRNA would not be produced, which is essential for protein synthesis

• There is enough mRNA already in cells for protein synthesis to continue, without making more.

Answer explanation

DNA does not leave the nucleus, so without mRNA the cell would not be able to create new proteins.

Extreme temperature can cause enzymes to denature, which means they are no longer able to function.

If RNA polymerase enzymes started to denature, what effect would this have on the rates of transcription and translation?

• It would cause the rate of transcription to speed up.

• It would cause the rate of transcription to slow down.

• It would have no effect on the rate of translation.

Answer explanation

If RNA polymerase enzymes in a cell started to denature, this would cause the rate of transcription to slow down. This is because RNA polymerase would be unable to carry out its role in transcription, and mRNA would not be produced.

The first step of transcription involves an ______.

ON a mRNA strand, the base ______replaces thymine.

On the diagram below, fill in the missing bases on the mRNA strand.

On the diagram below , fill in the missing bases on the template strand.