PBS Unit 1.1 Review

decendent

a person who has died

Search Methods

grid, line, zone, spiral

evidence

the available body of facts or information indicating whether a belief or proposition is true or valid.

polygraph test

Test that measures respiration, blood pressure, and perspiration while person is asked a series of questions; outcome is a diagnostic opinion about honesty.

heart rate

A measure of cardiac activity usually expressed as the number of beats per minute.

pulse

Beat of the heart as felt through the walls of the arteries.

respiratory rate

number of breaths per minute

trace evidence

small but measurable amounts of physical or biological material found at a crime scene

hair cortex

Middle, thickest portion of a hair shaft

hair cuticle

Outermost layer of hair; consisting of a single, overlapping layer of transparent, scale-like cells that look like shingles on a roof.

hair medulla

innermost portion of a hair shaft

ridge pattern

recognizable pattern of ridges in a fingerprint

Fingerprint Minutiae

characteristics of ridge patterns

Forensic Science

The application of scientific knowledge to questions of civil and criminal law.

another name for red blood cells

erythrocytes

Another name for white blood cells

leukocytes

another name for platelets

thrombocytes

function of red blood cells

transport oxygen and carbon dioxide

Function of white blood cells

fight infections

function of platelets

blood clotting

Function of plasma

mostly made of water, transports materials in blood, allows for diffusion into/out of blood

Hemoglobin

iron-containing protein in red blood cells that carries oxygen for delivery to cells

positive control

Group expected to have a positive result, allowing the researcher to show that the experimental set up was capable of producing results.

negative control

Control group where conditions produce a negative outcome. Negative control groups help identify outside influences which may be present that were not accounted for when the procedure was created.

presumptive test

test that presumes the presence of the questioned substance; also called a screening test.

confirmatory test

a test that specifically identifies one substance

Blood antigens

Proteins found on the erythrocyte cell surface. (A, B, and Rh) are used to differentiate blood groups.

Antibodies

Proteins that attach to antigens, keeping them from harming the body

Hypothesis

a proposed explanation made on the basis of limited evidence as a starting point for further investigation.

independent variable

The experimental factor that is manipulated by the scientist

dependent variable

what is measured or observed in an experiment

Cell

The basic unit of structure and function in living things

Nucleus

An organelle that contains genetic material

Histones

protein molecules around which DNA is tightly coiled in chromatin

deoxyribonucleic acid (DNA)

A double-stranded, helical nucleic acid molecule capable of replicating and determining the inherited structure of a cell's proteins.

Genetics

The scientific study of heredity

Gene

A segment of DNA on a chromosome that codes for a specific (protein) trait

Genome

All the genetic information in an organism; all of an organism's chromosomes.

Chromosomes

threadlike structures made of DNA molecules that contain the genes

base pairs

Any of the pairs formed between complimentary bases in the two nucleotide chains of DNA, such as A-T and C-G (DNA)

Eukaryotic cells

Contain a nucleus and other organelles that are bound by membranes.

prokaryotic cell

A type of cell lacking a membrane-enclosed nucleus and membrane-enclosed organelles; found only in the domains Bacteria and Archaea.

Organelle

A tiny cell structure that carries out a specific function within the cell

Nucleotide

monomer of nucleic acids made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base

DNA profile

a visual representation of a person's unique DNA sequence

restriction enzymes (restriction endonucleases)

Enzymes that recognize specific double-stranded DNA sequences and cuts it

PCR (polymerase chain reaction)

technique that allows molecular biologists to make many copies of a particular gene

Recognition site (restriction site)

specific sequence where a restriction enzyme will cut (palindrome)

restriction digest

A technique in which restriction enzymes are used to cut DNA at specific sequences.

gel electrophoresis

Procedure used to separate and analyze DNA fragments by placing a mixture of DNA fragments at one end of a porous gel and applying an electrical voltage to the gel

Restriction Fragment Length Polymorphisms (RFLPs)

Differences in DNA sequence that can result in different patterns on an agarose gel

DNA ladder (marker)

set of known DNA fragments with different sizes in base pairs or kilo bases. these DNA fragments are separated and visualized as DNA bands on a gel. used to determine the size and quantity of DNA fragments

DNA Bands

lines on the agarose gel once stained

well

hole in a agarose gel where DNA is inserted

agarose gel

a jelly-like slab used to separate molecules on the basis of molecular weight

micropipettor

instrument used to accurately withdraw and dispense very small amounts of reagents in the microliter range, which is necessary for DNA

Accuracy

A description of how close a measurement is to the true value of the quantity measured.

Precision

a measure of how close a series of measurements are to one another