PRELIMS Flashcards
1
Q
is the genetic material present in the cells of all living organisms. It is the fundamental building block for an individual’s entire genetic make-up
A
DNA
2
Q
is a most powerful tool for human identification and has clear forensic applications in identity testing (crime scene and mass disaster investigations) and parentage determination.
A
DNA analysis
3
Q
can sometimes prove a person’s innocence or guilt, or, at least, it can prove whether a person was in the vicinity of the crime scene.
A
DNA
4
Q
is responsible for building and maintaining one’s human structure. Our
A
DNA
5
Q
Structurally, it is a double-helix composed of two complimentary strands.
A
DNA
6
Q
It looks like a twisted ladder (double helix) and is found inside the nucleus of our cells.
A
DNA
7
Q
DNA stands for
A
deoxyribonucleic acid
8
Q
All genetic code is made up of combinations of four chemical units called
A
nucleotides
9
Q
four chemical units called nucleotides:
A
- ADENINE (A)
- THYMINE (T)
- CYTOSINE (C)
- GUANINE (G)
10
Q
Adenine pairs with
A
Thymine (A with T)
11
Q
Guanine pairs with
A
Cytosine (G with C)
12
Q
occurs in different combinations to code for a specific amino acid.
A
A, C, G and T
13
Q
are the building blocks for proteins. This means our DNA codes for different proteins that perform specific functions in our body.
A
Amino acids
14
Q
It is the detection, classification and study of various bodily fluids such as blood, semen, fecal matter and perspiration and their relationship to a crime scene
A
FORENSIC SEROLOGY
15
Q
A range of laboratory tests using antigens and antibodies
A
SEROLOGY
16
Q
is a foreign substance that enters your body. This can include bacteria, viruses, fungi, allergens, venom and other various toxins.
A
antigen
17
Q
is a protein produced by your immune system to attack and fight off these antigens.
A
antibody
18
Q
It is a specialized bodily fluid that is composed of two substances – cells and plasma.
It is responsible for delivering nutrients and oxygen to and transporting wastes and carbon dioxide from cells, tissues, and organs.
A
BLOOD
19
Q
ɷ Transporting oxygen and nutrients to the lungs and tissues
ɷ Forming blood clots to prevent excess blood loss
ɷ Carrying cells and antibodies that fight infection
ɷ Bringing waste products to the kidneys and liver, which filter and clean the blood
ɷ Regulating body temperature
ɷ Regulating pH of the body fluids
A
FUNCTIONS OF BLOOD
20
Q
the two main organs that regulate the pH of the blood, often at the same time.
A
lungs and kidneys
21
Q
can help regulate blood pH rapidly through the process of exhaling carbon dioxide, sometimes producing changes within seconds
A
lungs
22
Q
the actual cellular components of the blood
A
Formed elements (45%)
23
Q
is the fluid portion of the blood
A
Plasma (55%)
24
Q
Erythrocytes
A
Red blood cells)
25
Leukocytes
White blood cells
26
Thrombocytes
Platelets
27
ɷ Contain haemoglobin and distribute oxygen
ɷ Account for ~93% of all blood cells
ɷ Represent ~25% of all cells in the body
ɷ Over 2 million made every second
ɷ Live for about 120 days before recycled
ERYTHROCYTES
28
is a measure of RBC volume (45% of whole blood)
Haematocrit
29
ɷ Function in the immune system
ɷ Five types categorized by immune target and function
ɷ Account for ~0.1% of all blood cells
ɷ Live for 3-4 days before recycled
ɷ Main component of pus
LEUKOCYTES
30
ɷ Responsible for blood clotting
ɷ Produced by fragmentation of larger stem cells
ɷ Account for ~7% of all blood cells
ɷ “Live” for 5-9 days before recycled
ɷ Form long fibers to trap RBCs and form scab
THROMBOCYTES
31
ɷ The fluid portion of blood and accounts for 55% of the blood content.
ɷ It is mostly water, and it contains the clotting factors, other proteins, hormones, and various chemicals.
ɷ Serum is the liquid that separates
PLASMA
32
is the liquid that separates from the blood when a clot is formed
Serum
33
PARTS OF PLASMA PROTEINS Determined by means of
Electrophoresis
34
A Phenolphthalein solution is used to show the possible presence of blood based upon a peroxidase reaction of hemoglobin which produces a pink color.
PHENOLPHTHALEIN TEST
35
positives from other substances, such as saliva, pus, malt extract, vegetable extracts, and the salts of certain heavy metals. A false positive reaction has also been observed with rust
PHENOLPHTHALEIN TEST
36
An obsolete colorimetric test once used to detect heme (haemoglobin, myoglobin and related pigments), which fell into disfavour due to benzidine's carcinogenic potential.
BENZIDINE TEST
37
Very delicate test in the presence of blood, BLUE color rapidly develops
BENZIDINE TEST
38
False Positive Reactions:
Apples, Potatoes, Bone Marrow, Brain Tissue, Spinal Fluid, Saliva, Mucus and Pus
BENZIDINE TEST
39
A chemical compound, known as Luminol, is used in solution or sprayed onto suspected surfaces. This compound gives a strong blue fluorescence when viewed with a UV light.
LUMINOL TEST
40
False positives have been observed with the presence of copper salts.
LUMINOL TEST
41
If blood is present, it produces GREEN or BLUE-GREEN color when the hydrogen peroxide is added to the solution of leucomalachite green
LEUCOMALACHITE GREEN TEST
42
ɷ It is a very delicate test revealing the presence of fresh blood
ɷ It may not detect old blood
ɷ It could also lead to false positive results.
ɷ Positive Result: Blue Color / Blue-Green Color
GUAIACUM TEST
42
It is also called Van Deen’s or Schoenbein’s Test
GUAIACUM TEST
43
It is based on the formation of distinctive needle-shaped pink-coloured crystals of pyridine haemochromogen when a blood sample is treated with Takayama’s reagent.
TAKAYAMA TEST
44
This test is also known as haemochromogen crystal assay.
TAKAYAMA TEST
45
This test was first introduced by a Polish anatomist Ludwig Karl Teichmann in 1853. It is based on the formation of distinctive rhombus-shaped crystals of haemin when a blood sample is treated with Teichmann’s reagent.
TEICHMAN TEST
46
Using Wet Mount Preparation and Fixed Stain Preparation, a suspected blood stain could be confirmed under an electric microscope. When samples are properly prepared, morphological characteristics of human blood can be observed and will confirm the presence of blood.
MICROSCOPY
47
is a body fluid produced by male individuals for fertilization
SEMEN
48
is a mixture of various fluids that carry live spermatozoa to the female ovule for fertilization
SEMEN
49
A fertile semen sample holds tens of millions of spermatozoa per milliliter and can provide useful
DNA evidence
50
The volume of ejaculate is anywhere between
2-6 milliliters
51
is a protein-rich fluid originating primarily from the prostate and seminal vesicle.
Seminal fluid
52
is an important part in the routine investigation of sexual offenses like:
* Rape
* Adultery
* Sodomy
* Bestiality
* Sexual homicide
semen and seminal stain
53
WHERE SEMEN CAN BE FOUND
* AS FRESH in the
vaginal contents and rectal contents of the victim.
54
WHERE SEMEN CAN BE FOUND AS WET OR DRIED in
hair and skin around the genitals
55
WHERE SEMEN CAN BE FOUND AS DRIED STAINS in
underclothing and bed sheets
56
complete lack of semen
Aspermia
57
condition wherein there is absence of spermatozoa in the seminal fluid.
Azoospermia
58
condition where there is abnormal low sperm counts or with few spermatozoa in the seminal fluid.
Oligospermia
59
may be preserved by a few drops of toulol or 10% solution of formalin during hot weather where there is danger of putrefaction.
Fluid semen
60
name after Dr. Florence of Lysons who first introduced the test.
* Positive result: crystals of choline periodide are dark brown, rhombic or needle shaped that occur singly or in cross or even in clusters.
Florence test
61
almost specific for human semen. Seminal stain as old as 6 years are said to respond to this test.
* Positive result: crystals that are slender yellow tinted, rhomboid needles with obtuse angle or appear as ovoid crystals.
Barberio’s test
62
the best way to locate and characterized a seminal stain. Has replaced Florence test in reliability and very specific for human and higher apes
* Positive result: orange-red pigment
Acid phosphatase test
63
main purpose is to determine the presence of spermatozoa. The identification of spermatozoa at present is the only specific test for semen.
Microscopic examination
64
spermato precipitins are of value in the identification of seminal fluid in certain case like bestiality. This test was originally proposed by Farnum in 1901.
Biological examination
65
is a biological secretion inside the mouth that is primarily a digestive aid as the salivary amylases break down the starches in our food.
SALIVA
66
It contains urea, glucose, progesterone, various traces of acids, amino acids, creatinine, and more than 1,000 different proteins
SALIVA
67
contains mostly water, but bacteria, skin cells from the inside of the mouth (buccal cells), and the substance we test for – α-amylase – is also present.
* This enzyme helps break down carbohydrates, but can vary widely between people.
Spit
68
is specific for human salivary α-amylase. No cross-reaction has been observed with blood, semen, urine, vaginal secretions, or menstrual blood.
Rapid Stain Identification test / RSID Saliva test
69
is kind of like a pregnancy test. You’re going to get two stripes for positive, or one for negative.
RSID test
70
- deals with the application of genetic knowledge to legal problems and legal proceedings.
- also a branch of forensic medicine which deals more broadly with the application of medical knowledge to legal matters.
FORENSIC GENETICS
71
identified the DNA molecule which he called then “nuclein”
Johann Friedrich
72
a German biochemist,
- identified the nuclein as a nucleic acid and provided its present chemical name, deoxyribonucleic acid (DNA)
Albrecht Kossel
73
described the ABO blood grouping systems and observed that individuals could be placed into different groups based on their blood type
Karl Landsteiner
74
published a book describing the use of ABO typing to resolved paternity case
Leone Lattes
75
- is represented by substances on the surface of red blood cells (RBCs).
- These substances are important because they contain specific sequences of amino acid and carbohydrates which are antigenic.
- Became a standard in forensic laboratories before the advent of DNA testing especially in paternity cases
ABO BLOOD TYPING / ABO BLOOD GROUP
76
BASIC PRINCIPLE OF SEROLOGY
“For every antigen, there exists a specific antibody”
77
● Can be done on a slide or in a test tube at a room temperature
● Done by mixing unknown RBC with known typing sera
● Use of commercial reagents, anti-A (blue) and anti-B (yellow)
● Ingredients are mixed in a slide with applicator stick and then tilted back and forth and observed over a 2 minute period for agglutination
Cell Grouping/Forward Typing or Direct Blood Grouping
78
- is tested with suspensions of known A & B cells
- Done to crosscheck the result of forward typing
- To test the reactivity of anti-A and anti-B typing reagents
Serum Testing/Reverse Typing
79
is a type of protein on the outside of your red bood cells
Rh factor
80
proved that DNA is a genetic material carrying at least some of the blueprint of life
Alfred Hershey and Martha Chase
81
discovered the structure of DNA which they described as a twisted ladder or double-helix
James Watson and Francis Crick
82
Developments in molecular biology allowed scientists to examine the _____
DNA sequence
83
could be detected in southern blotting
DNA polymorphs
84
conceptualized the PCR process
Kary Mullis
85
as the basis in assessing the probative value of DNA evidence.
Vallejo Doctrine
86
branch of biological sciences which deals with the transmission of characteristics from parent to offspring.
Genetics
87
-Is a distinct portion of a cell’s DNA
-are coded instructions for making everything the body needs, especially proteins.
GENE
88
- It is one particular section of a DNA molecule that tells a cell to perform one specific task.
-
GENE
89
- Are pairs or series of genes on a chromosomes that determine the hereditary characteristics
-One of the alternative genetic marker, component/ DNA type.
ALLELE
90
- set of genes in our DNA which is responsible for a particular trait.
- refers to the genetic composition of an organism.
- is determined by the genes we inherit from our parents.
- influence how certain traits are expressed in the phenotype, which is what we can observe externally
- IT IS THE GENETIC CODE
GENOTYPE
91
is the set of observable traits
PHENOTYPE
92
- An organism in which 2 copies of genes are identical or have the same DNA
- It means you carry two genes that are the same for each trait
HOMOZYGOUS
93
- An organism which has different alleles of the gene.
-An individual carry two different genes for each trait.
HETEROZYGOUS
94
The allele that is expressed and overrules the recessive gene. Denoted by using a capital letter.
DOMINANT
95
is defined as the trait that shows first or is visibly expressed in the individual
dominant trait
96
- are expressed only if both the connected alleles are recessive. Denoted by using small case letter.
- The trait which is present at the level of the genome but is hidden and does not express in the organism
Recessive traits
97
- Father of Modern Genetics
-He illustrated the basic patterns of inheritance of characters from parents to offspring wherein he showed that that factors of inheritance are transferred from parents to offspring.
-Mendel’s Law of Dominance; Law of Segregation; and Law of Independent Assortment
GREGOR MENDEL
98
- It is also called the first law of inheritance.
-‘‘The two copies of each genetic factor segregate during the development of gametes, to ensure that each parent’s offspring attains one factor.’’
States that each pair of alleles segregates, or separates, during meiosis so that they can transfer specifically to separate gametes
LAW OF SEGREGATION
99
- Also called the second inheritance law,
-it states that: ‘‘Separate couples with alleles are transferred separately from each other to the next generation. As a result, gene inheritance does not influence gene inheritance somewhere else at one position in the genome.’’
- When parents with pure contrasting traits are crossed together, only one form of trait appears in the next generation.
LAW OF INDEPENDENT ASSORTMENT
100
An allele that always controls a trait is called
dominant allele
101
An allele that is hidden when paired with a dominant allele
recessive allele
102
- When an individual inherits two or more characteristics, those characteristics are assorted independently during the production of gametes. This gives the different traits an equivalent probability of occurring together.
- This indicates that the inheritance of one character will not influence the inheritance of the other.
- Mendel’s Law of Dominance states that: ‘‘Only one sort of the trait will show in the next generation in a cross of parents which are pure for different traits. In the allele, children that are hybrid for a trait will only show the dominant characteristic, and children that are not hybrid for a trait will show recessive traits.’’
MENDEL’S LAW OF DOMINANCE
103
- is a tabular summary of possible combinations of maternal alleles with paternal alleles.
- This tables can be used to examine the genotypical outcome probabilities of the offspring of a single trait, or when crossing multiple traits from the parents.
PUNNETT SQUARE
104
- It is a genetic material that transfer the genetic information from one organism to their off spring.
- Located in nucleus and mitochondria
-is a long chain polymer of nucleotides.
DNA
105
molecule of DNA is made up of millions of tiny subunits called
Nucleotides
106
Each nucleotides is consist of
1. Phosphate group
2. Pentose Sugar
3. Nitrogenous base
107
- This is part of the cell that contains the chromosomes that have the Nuclear DNA.
-is defined as a double-membraned eukaryotic cell organelle that contains the genetic material.
NUCLEUS
108
- It is responsible for storing the cell’s hereditary material or the DNA.
-It is responsible for coordinating many of the important cellular activities such as protein synthesis, cell division, growth and a host of other important functions.
NUCLEUS
109
Popularly known as the “Powerhouse of the cell
- are a double membrane-bound organelle found in most eukaryotic organisms. They are found inside the cytoplasm and essentially function as the cell’s “digestive system.”
MITOCHONDRIA
110
to produce energy through the process of oxidative phosphorylation. It is also involved in the following process:
- Regulates the metabolic activity of the cell
- Promotes the growth of new cells and cell multiplication
- Helps in detoxifying ammonia in the liver cells
MITOCHONDRIA
111
- The basic unit of heredity that controls the development of specific characteristics in the new individual
- Specific segments of DNA that control cell structure and function; the functional units of inheritance.
- Coding region of DNA
GENE
112
113
Threadlike bodies that appear in the nucleus of every body cell
CHROMOSOMES
114
means that a specific gene is not on a sex chromosome and is a numbered chromosome. Humans have 46 total chromosomes.
Autosomal
115
Chromosomes other than the sex chromosomes
AUTOSOMES
116
