DNA Flashcards
Chromosome
A cell structure that contains genetic information along strands of DNA
DNA fingerprint
Pattern of DNA fragments obtained by examining a persons unique sequence of DNA base pairs
Electrophoresis
A method of separating molecules
Gene
Segment of DNA in a chromosome that contains information used to produce a protein or RNA molecule
Allele
An alternate form of a gene
Polymerase Chain Reaction (PCR)
A method used to rapidly make multiple copies of a specific segment of DNA
Restriction enzyme
A molecule that cuts a DNA molecule at a specific base sequence
Short Tandem Repeat (STR)
Short number of tandem repeats (2-5 base pairs) of short DNA sequences with varying numbers of repeats found among individuals
Tandem
Next to each other
VNTR
Variable number of tandem repeats (9-80 base pairs) of a short DNA sequence with varying numbers of repeats among individuals
DNA extraction
Process of removing DNA from a cell
Homologous chromosomes
Pair of chromosomes in which one chromosome was inherited from the male parent and the other was inherited by the female parent
Nucleotide
Subunit of DNA and other nucleic acids
True or false? Correct the statement if it’s false
There are 35 chromosomes in each human cell nucleus.
False 46 chromosomes
True or false? Correct the statement if it’s false
Chromosomes are tightly coiled DNA.
True
True or false? Correct the statement if it’s false
DNA determines the body characteristics of an organism
True
True or false? Correct the statement if it’s false
DNA is extracted from red blood cells found in a blood sample.
False
There is no DNA in red blood cells
The DNA inside of a persons skin cell is the same as the DNA inside of their white blood cells.
True
True or false? Correct the statement if it’s false
Identical twins have different base sequences of DNA.
False
Identical twins are the only people who have exactly the same DNA sequence.
Does A pair with T, C or G?
A pairs with T
Does C pair with A,G or T
C pairs with G
Does T pair with C, A or G?
T pairs with A
Does G pair with A, C or T
G pairs with C
True or false? Correct the statement if it’s false
In the DNA structure, adenine (A) will only link with cytosine (C) and guanine (G) will only link with thymine (T)
False
A pairs with T
C pairs with G
True or false? Correct the statement if it’s false
The monomer of DNA is a nucleotide.
True
True or false? Correct the statement if it’s false
DNA’s structure is 3 strands of the molecule twisted together.
False
2 strands. Known as double helix
True or false? Correct the statement if it’s false
DNA evidence is class evidence.
False
Individual evidence
True or false? Correct the statement if it’s false
PCR stands for polymerase chain reaction, and is the technique for making many copies of DNA in the lab.
True
True or false? Correct the statement if it’s false
The Innocence project is an organization which tests DNA evidence from old cases and exonerates the wrongfully convicted.
True it exonerated 306 people
What are the three steps for creating a DNA fingerprint? (In order)
- DNA extraction from cells
- PCR to make more copies of the DNA.
- Gel electrophoresis to separate the DNA in bands to create the DNA fingerprint.
What type of cells are usually taken from a suspect when a DNA sample is collected?
Cheek cells
Describe how DNA moves through the gel electrophoresis and how that information is used to analyze the DNA fingerprint?
- The DNA moves from the negative end towards the positive end.
- Small pieces move quicker than larger pieces.
What are the three parts of a nucleotide?
Phosphate, sugar and a nitrogen base
What is 1 difference between analyzing a gel for a match between 2 DNA samples and analyzing gel for a paternity test?
For the 2 DNA samples you look for two lanes of DNA fingerprint ending which have banding patterns that match exactly EVERY band
- for paternity test (father) you look for one band at each STR region matching exactly with one of the fathers band from each STR region
At one STR region a person has 5 STR repeats on the maternal chromosome and 11 STR repeats on their paternal chromosome. Write the Genotype for this person?
5,11
At one STR region a person has 4 STR repeats on the maternal chromosome and 8 STR repeats on their paternal chromosome. Write the Genotype for this person?
4,8
At one STR region a person has 3 STR repeats on the maternal chromosome and 7STR repeats on their paternal chromosome. Write the Genotype for this person?
3,7
How many STR regions does the FBI test?
13
Why doesn’t the FBI test for more STRs?
If they test for less there’s a chance someone will have the same DNA which leads to a wrongful conviction.
Heterozygous
2 DIFFERENT numbers
Homozygous
SAME number twice
