6.1 Forensic Biology Flashcards
What is a fingerprint?
The pattern of skin folding on the fingers of humans - each person’s pattern is unique.
What are sebaceous glands?
Skin glands associated with hair follicles that secrete an oily substance.
What is DNA profiling?
A technique used to identify individuals. Relies on differences in the number of times a mini or micro satellite is repeated.
What are introns?
Non-coding blocks of DNA, or intragenic regions.
What are exons?
Coding regions of DNA, or expressed regions.
What are short tandem repeats?
Another term for satellites - DNA sequences within introns repeated many times.
What is a restriction enzyme?
An enzyme produced by bacteria that can cut DNA molecules at specific sites.
What is agarose gel electrophoresis?
Use of an agarose gel matrix place in salt buffer in which molecules of DNA can be separated on the basis of size, when a current is passed through the gel.
What is southern blotting?
The process by which DNA fragments are transferred from the agarose gel to a nylon or nitrocellulose membrane.
What is a nylon/nitrocellulose membrane?
A charged membrane that provides a solid support to which DNA separated by gel electrophoresis can be transferred. Used to allow subsequent manipulations of the DNA.
What is agarose?
A substance that when heated with buffer and cooled, forms a gel.
What is hybridisation?
The process where two complementary DNA strands will anneal by hydrogen bonding.
What is a gene probe?
A short single stranded length of DNA, that is complementary to a target gene sequence that has attached to it a fluorescent marker.
What is the polymerase chain reaction?
A technique that allows the automated replication of a particular stretch of DNA using thermostable DNA polymerase.
What is DNA polymerase?
An enzyme which catalyses the joining together of individual nucleotides to form a molecule of DNA. Thermostable.
What are primers?
Short single stranded sections of DNA used in PCR, which are complementary to the sequence either side of the target sequence. Marked with fluorescent tags.
The cooling of the body follows a…
Sigmoid curve
What is rigor mortis?
The stiffening of muscles after death due to lack of ATP in muscle cells.
What is ATP?
Adenosine triphosphate. The common ‘energy currency’ of all cells.
What is lactic acid?
Chemical formed by anaerobic respiration in animal cells, which causes the pH to drop, inhibiting further enzyme reactions.
What is autolysis?
Early stage of decomposition involving the body’s own enzymes from the digestive tract and lysosomes.
What is one of the first signs of decomposition?
Greenish discolouration
Which gases build up to form bloating of the body?
Hydrogen sulphide, methane, carbon dioxide, ammonia, hydrogen
What is forensic entomology?
The application of knowledge about insect lifecycles to estimate time of death.
