Biological Theories And Technology

Question 1

What does the Cell Theory tell us?

Answer 1

-All living organisms are composed of one or more cells
-Cell is basic unit of structure, function, and organization
-All cells one from preexisting, living cells
-Cells carry hereditary information

Question 2

What does the RNA World Hypothesis tell us?

Answer 2

-Self replicating RNA molecules were precursors to life
-RNA stores genetic information like DNA
-RNA can catalyze chemical reactions like enzymes

Question 3

What does the Central Dogma of Biology tell us?

Answer 3

The general flow of genetic information is from DNA—>RNA—>Protein

Question 4

What is a light microscope?

Answer 4

Uses visible light to view a thin sample

Question 5

What is a scanning electron microscope?

Answer 5

It is used to view surface of 3D objects with high resolution

Question 6

What is a transmission electron microscope?

Answer 6

It is used to view thin cross sections and internal structures within samples at very high magnification

Question 7

What is a confocal laser scanning microscope/fluorescence?

Answer 7

It can observe specific parts of a cell using fluorescent tagging antibodies (ex: used to view chromosomes during mitosis

Question 8

PCR creates a large amount of DNA by amplifying a DNA sample through the following steps:

Answer 8

1. Denaturation: high heat separates double stranded DNA
2. Annealing: sample is cooled so primers attach to separated strands
3. Elongation: polymerase synthesize new strands
   TIP: cycle repeats to increase amount of DNA exponentially

Question 9

What is reverse transcriptase?

Answer 9

-used to SYNTHESIZE DNA from an RNA template
-in some lab procedures, it is used to create COMPLEMENTARY DNA (cDNA) of an mRNA template. cDNA lacks introns
-naturally used by viruses

Question 10

What is Centrifugation?

Answer 10

-technique to separate a liquified sample into its different components by spinning it rapidly
-largest/most dense separate first, forming a PELLET at bottom of sample
-cell fractionation (largest to smallest): nuclei > mitochondria/chloroplast > ribosomes

Question 11

What is DNA sequencing?

Answer 11

Used to determine the sequence of base pairs in a DNA or RNA molecule
EXAMPLE: Dideoxy Chain Termination is based on the principle that during DNA synthesis, addition of a nucleotide requires a FREE OH group on the 3’ carbon of the sugar of the last nucleotide of the growing DNA strand

Question 12

Blotting techniques are used for identifying specific fragments of DNA, RNA, or protein. What is the blotting methodology?

Answer 12

1. Electrophoresis is used to separate sample
2. Sample is transferred to nitrocellulose gel
3. Probe is added to hybridize and mark target fragment (hybridization is when nucleic acids form complementary base pairs with nucleic acids of different strand)

Question 13

What are the 3 types of blotting:

Answer 13

1. Southern -DNA
2. Northern - RNA
3. Western - Protein

Question 14

What is Gel Electrophoresis?

Answer 14

-used to separate DNA molecules by size and charge: the smaller the molecule, the farther it travels down the gel
-after separating the DNA sample, it can be sequenced or probed to find location of specific sequence

Question 15

What is Microarray Assays?

Answer 15

It is used to monitor the expression of large groups of genes across a gene

Question 16

Recombinant DNA contains segments from multiple sources. The process to making and using recombinant DNA includes:

Answer 16

1. Using restriction endonucleases (restriction enzymes) to cut specific segments of DNA called restriction sites. These enzymes create STICKY ENDS, which allow new DNA pieces to bind
2. DNA LIGASE connects the different fragments together
3. A vector can then be used to TRANSFER foreign DNA into another cell
   Examples of vectors: plasmids and bacteriophages

Question 17

What are gene libraries?

Answer 17

Collections of DNA pieces from a genome