MRS. SMILON'S- Forensic Science DNA Unit Test

DNA is known as a _________

double helix

Because each molecule is composed of two strands

What is the electronic database of DNA profiles in the U.S.?

CODIS (Combined DNA Index System)

What are the 4 steps of DNA fingerprinting?

1. Extraction
2. Restriction fragments
3. Amplification
4. Electrophoresis

Except for identical twins, no two people on earth have the same…

DNA

What are examples of biological evidence?

Saliva, semen, hair, blood, urine, skin

What are the four DNA base pairs?

Adenine, cytosine, thymine, guanine

List three uses for DNA.

1. Eliminate suspects

2. matching DNA from the crime scene

3. determine maternity, paternity, or relativity, identify human remains, or free falsely imprisoned individuals

Genetic information is stored in molecules of DNA making up structures called ________

Chromosomes

James Watson and Francis Crick received the 1953 Nobel Prize for their work on describing the structure of DNA which is….

A double helix that resembles a twisted ladder

In the nucleus of most human body cells, there are __ pairs of chromosomes

23

The total amount of DNA in a cell, which is contained in chromosomes and mitochondrial, is called the human _________

Genome

Within the non-coding sections of DNA, certain short sequences are repeated…

Multiple times

Molecular scissors that cut DNA at specific base sequences

Restriction enzymes

The method of separating the molecules within an electric field, based on their size, is called _______

Electrophoresis

A method used to rapidly make multiple copies of a specific segment of DNA is called ______

PCR (polymerase chain reaction)

tandem repeats of short DNA sequences (2-5 pairs) with varying numbers of repeats between individuals is called ___________

STR (short tandem repeats)

What are the complementary pairs of DNA bases?

Adenine-Thymine
Cytosine-Guanine

what is an STR

a sequence of repeating bases in noncoding regions of DNA that are used in DNA profiling.

what is a genome?

all the DNA found in human cells

What is the general structure of the DNA molecule

DNA is composed of long repeating units (monomers) known as nucleotides.

Why is mtDNA (mitochondrial DNA) important to genetic profiling?

the DNA located in mitochondria and is passed down maternally (fathers cannot pass this down)

the difference between nuclear DNA and mitochondrial DNA

Nuclear DNA is randomly taken half from a mother and the other half from a father. MtDNA is found in the mitochondria and is passed down maternally.

What is PCR used for

amplifies a single copy or a few copies of a segment of DNA.

What are restriction enzymes?

an enzyme produced chiefly by certain bacteria, having the property of splitting DNA molecules at or near a specific sequence of bases.

what does gel electrophoresis do?

separates macromolecules like DNA, RNA and proteins.

pedigree

A diagram that shows the occurrence of a genetic trait in several generations of a family.

How many core Codis Loci are there?

13

Electropherogram, allelic ladder

One peak at a single locus: homozygous
Two peaks at a single locus: heterozygous

Pyrimidines

Cytosine and Thymine

Purines

Adenine and Guanine

DNA Profile

a visual representation of a person's unique DNA sequence

Charge of DNA

negative

Photo 51

The picture of the structure of DNA taken by Rosalind Franklin

DNA replication

The process in which DNA makes a duplicate copy of itself by breaking the hydrogen bonds between the bases and adding new bases (nucleotides) to the exposed sides of the DNA strand. Two identical copies are thus made.

Semiconservative Replication

The process in which the DNA molecule uncoils and separates into two strands. Each original strand becomes a template on which a new strand is constructed, resulting in two DNA molecules identical to the original DNA molecule.