03 DNA Technologies and Genetic Engineering Free Online FlashCards

How does gel electrophoresis separate DNA fragments?

DNA moves through a porous gel toward the positive electrode; shorter fragments generally travel farther than longer ones.

What determines which DNA region PCR amplifies?

PCR selectively copies a DNA region defined by two primers that bind on opposite sides of the target.

What happens during PCR denaturation?

Heating separates the two DNA strands so they can serve as templates in later PCR steps.

What does quantitative PCR estimate?

qPCR monitors fluorescence during amplification to estimate the starting amount of target DNA.

What does reverse transcriptase do in RT-PCR?

Reverse transcriptase first converts RNA into complementary DNA (cDNA), which can then be amplified.

What does DNA sequencing determine?

DNA sequencing determines the order of nucleotide bases in a DNA molecule.

When is Sanger sequencing useful?

Sanger sequencing reads a selected DNA fragment, such as a PCR product or plasmid insert.

How does bioinformatics help interpret sequencing reads?

Bioinformatics compares reads with a reference, identifies sequence differences, and can estimate how common variants are in a sample.

What is the role of DNA ligase in recombinant DNA cloning?

In recombinant DNA cloning, a DNA fragment is joined to a carrier, often a plasmid; DNA ligase joins the fragment and vector.

How does guide RNA direct Cas9 in CRISPR–Cas9 editing?

A guide RNA directs Cas9 to a complementary target sequence near a required DNA signal called a PAM.

How do two common cellular repair pathways shape CRISPR editing outcomes?

Non-homologous end joining can create small insertions or deletions that disrupt a gene; homology-directed repair can use a supplied template to introduce a planned change, though efficiency varies.

Why verify genome-editing outcomes?

Researchers verify intended changes and may examine likely off-target sites because editing can be incomplete, vary among cells, or produce unexpected changes.