Bio practical Flashcards
Denaturing step
double-stranded DNA is heated to separate it into single strands
Annealing step
The temperature is lowered to allow the DNA primers to attach to the template DNA
Extending step
The temperature is raised again to allow the Taq polymerase enzyme to make a new strand of DNA
polymerase chain reaction (PCR) Steps
- Denaturing
- Annealing
- Extending
which tissues mitosis primarily occurs in humans?
somatic tissues
which tissues mitosis primarily occurs in plants?
meristematic tissues
duplicated
a chromosome that has an extra copy of a DNA segment
unduplicated
a single, individual chromosome that has not yet undergone DNA replication
diploid
two complete sets of chromosomes, one from each parent
Haploid
having a single set of unpaired chromosomes.
calculate the length of time that mitosis occurs within a cell cycle
= # of cells in a certain phase / # of cells counted all together
which organs or tissues meiosis occurs in animals and plants to produce gametes?
the gonads (specifically the testes in males and ovaries in females)
Meiosis I
effectively reducing the chromosome number by half
Meiosis II
separate sister chromatids
Taq DNA Polymerase
heat-resistant DNA polymerase enzyme that’s used to amplify DNA sequences
DNA primers
short, single-stranded nucleic acid sequences that are used to initiate DNA synthesis
deoxynucleotides
building blocks to create new DNA strands
and are made up of three parts:
A deoxyribose sugar, A nitrogenous base, A phosphoryl group
thermal cycler
heats and cools a DNA sample in order to perform the PCR
How is qPCR different from standard PCR where PCR products are visualized on a gel?
Amplification process is the same as PCR except that the reaction includes a fluorescent dye that bind to double-stranded DNA
What is the Ct (cycle threshold) value?
refers to the number of cycles needed to replicate enough DNA/RNA to be detected (crosses a threshold line)
What is the purpose for performing RT-qPCR
(Reverse Transcriptase-qPCR)?
to detect and quantify RNA, and turn it into cDNA
Interpret what the R2 value and P-value of the standard curve means
R2 - indicating how well the linear relationship between concentration and signal fits the data
P-value - tells you how statistically significant that relationship is
Why is agarose used in gel electrophoresis?
allows for the separation of the DNA fragments during electrophoresis
What is agarose?
natural seaweed polysaccharide
how DNA fragments are separated by agarose gel electrophoresis
based on their size due to their negative charge
What are the advantages or disadvantages of Methylene Blue for staining DNA in a gel?
Can be seen in normal light but has low sensitivity
What are the advantages or disadvantages of Ethidium Bromide for staining DNA in a gel?
which is highly sensitive but considered a mutagen, but is high in toxicity
What are the advantages or disadvantages of SYBR Green for staining DNA in a gel?
provides high sensitivity similar to Ethidium Bromide while being less toxic, but typically requires a specialized blue light source for visualization and can be more expensive
How is micropipetting different between loading a sample into gel as compared to micropipetting a sample into a dry tube?
Never use second stop with the gel
How is BLAST used to compare and identify sequences?
compares nucleotide or protein sequences to sequence databases and calculates the statistical significance of matches
What does a MAX SCORE tell you?
the best possible match found within the aligned region
What does an E-value tell you?
the number of times you would expect to find a match with a similar score or better by chance
What does % IDENTITY tell you?
the percentage of nucleotides or amino acids that are exactly the same between your query sequence and the sequence it’s being compared to in the database
What is the ACCESSION NUMBER?
a unique identifier for a sequence record in a database
MUSCLE. What is it used for?
Aligines sequences
PHYLIP. What is it used for?
Creates cladogram graph
What does this phylogenetic tree (using the LDH gene) tell you about the relationship between these animals?
the closest evolutionary relationship is between the mouse and rat, followed by a grouping of the human, chimpanzee, and gorilla
describe how PCR amplifies specific regions of a template DNA
Using primers that bind to DNA that then allow DNA polymerase to create more copies of DNA strand (denaturing, annealing, and extending )
taxonomy
the science of classifying, describing, and naming organisms
systematics
looks at the evolutionary relationships between organisms
Clade
group evolved from a common ancestor.
phylogenetic tree
illustrates ancestral relationships among organisms
Bioinformatics
Using computers to analyze, store, and interpret biological data
What kind of information can you obtain from BLAST?
finds regions of local similarity between sequences
