Biology Quiz 3-7-22 Flashcards
What does Gel Electrophoresis do?
Separates DNA fragments based on size and shape.
What is Agarose?
A gel used in Gel Electrophoresis which has pores that the DNA must go through. (like jello)
Where do you load the DNA fragments in the gel?
The wells.
What ends do Restriction Enzymes produce?
Blunt or Sticky ends.
What is the point of Loading dye in the DNA samples?
The Loading dye weighs the DNA samples down into the well.
What is the difference in terms of distance and speed in the small and large DNA fragments?
The smaller DNA fragments travel farther and faster.
The larger DNA fragments travel slower and not as far.
What solution does the gel run in?
A solution of salt water and buffer.
What does the salt water and buffer do?
Salt Water: conducts electric current
Buffer: Helps maintain the pH of the solution so DNA doesn’t degrade
What are Short Tandem Repeats (STRs)?
Short Tandem Repeats: Within our introns, there are lengths of DNA that are repeated in tandem. Each person has a different number of repeats.
What is Restriction Fragment Length Polymorphism (RFLP)?
Restriction Fragment Length Polymorphism: Restriction enzymes are used to cut DNA into fragments containing genes and repeats. The different STRs will lead to fragments of different lengths for each person. (used to distinguish individuals, populations, or species or to pinpoint the locations of genes within a sequence.)
Why can’t DNA analysis definitively prove one is guilty or not?
There is a small probability that the DNA could look similar on more than one person.
The analysis could’ve been conducted with several errors that resulted in incorrect readings, human error, and others.
What side do the DNA fragments go away from/towards?
The DNA fragments are negatively charged, therefore go towards the positive side of the gel and away from the negative side.
What do Restriction Enzymes do?
They cut DNA at a specific sequence of nucleotides.
What is Polymerase Chain Reaction (PCR)?
PCR is a process where many copies of a particular gene can be made to allow us to study genes.
One biologist simply adds a short piece of DNA that is complementary to each end of the “parent” DNA stand to act as primers. The DNA is then warmed up to separate the two “parent” stands then cooled to let the primers bind to the now single-stranded DNAs. DNA polymerase is added to then make copies of the region between the primers to make the copies of the original DNA strand, similar to how mitosis works in nature.
Do red blood cells and hair cells have DNA?
While blood contains DNA, red blood cells themselves don’t have any since they lack a nucleus.
Hair Cells are rich in DNA.
