Dna: the code of life Flashcards
Discuss the competition over scientific by referring to how and why Watson and Crick cracked the genetic code
There is always competition in science over scientific discoveries.
Watson and Crick Built a model based on other peoples scientific ideas
Wilkins determined that DNA is shaped like a corkscrew
Wilkin worked with Franklin and together they discovered that they the phosphates are on the outside of DNA
Wilkins told watson and crick without Franklins permission
therefore leading Franklin not get regonisitions for her finding
What are the four nitrogenous bases found in DNA
A- adenine
T- thymine
C- Cytosine
G- guanine
(A+T) (C+G)
What are the two ladders “ladders of DNA”
Phosphate
Deoxyribose sugar (steps go in between the sugars)
What is the nucleotide unitt
deoxyribose sugar
phosphate
nitrogenous base
Where else do we find DNA
Mitochondrial DNA (mtDNA) is located in the mitochrondria while most dna is located in the Nucleus
What is the Significane of DNA in hereditary studies
DNA is responsible for the transmissions of hereditary characteristics and information. and transmits this information from one generation to the next. MtDNA- cna trace human ancestory
What is the significance of DNA in forensics
used for DNA profiling in criminal cases to determine whether the accused was inncoent or guilty . If the DNA profile (fingerprints) of a suspect matches that of the biological material collected at the crime then the suspect is almost certainly quality of the crime
So comparing “band” patterns of
different people, can link a suspect to a crime scene
Why is DNA profiling such a popular method
Each DNA pattern obtained is unique to an individual and is known as their profile. the probability of two people having the same Dna profile is vey rare (less than one in a billion)
Why isn’t DNA profiling always accepted by the court of law
there is no uniform method or standard for taking the the profile. It is possible to “plant” DNA at a crime scene to frame an innocent person, which could led to an innocent person being prosecuted and possibly a guilty person being set free
Briefly explain how DNA replication takes place cc
1- DNA unwinds from one end to appear as a ladder
2- “unzip” weak hydrogen bonds between nitrogen bases break and two single strands move apart
3- “pairing and bonding”- each single strand picks up free nucleotides from the nucleoplasm and becomes double stranded again
4- “winding” the new double strands are identical to each other and the original. Each double strand becomes twisted and helix in structure
Define DNA fingerprinting
a technique used for forensic identification by
extracting and identifying the base-pair pattern of an individual’s DNA.
What does PCR stand for and how is it used
Polymerase chain reaction
use- makes fingerprinting possible from small DNA samples. it replicates the DNA, multiplying a small sample. It is used to amplify small segments of a DNA to make millions
What are the advantaged of DNA fingerprinting
- solve criminal cases
-making positive identifications of human remains
-Paternity test 50% of fragments in a childs DNA fingerprint is derived from the mother and the other 50% from the father
-Diagnosis of inherited genetic disorders in unborn and new born babies
What are the disadvantages of DNA fingerprinting
- expensive
-subject to human error
-it can be used to frame innocent people - not everybody’s DNA has be profiles
- profiling an innocent persons DNA may infringe on individuals rights
