Genetics Final

Allele

Different forms of a gene

DNA extraction

the process of separating DNA from the rest of the cell -- Gather DNA sample, Centrifuge DNA (creates precipitate which contains only cell debris), Remove supernatant (liquid), Add ethanol to test tube, Centrifuge (another, smaller pellet with form containing only DNA)

Epigenetics

the study of environmental influences on gene expression that occur without a DNA change (environmental impacts on genetic makeup)

Eugenics

science dealing with improving hereditary qualities (although can be real sus real fast); Became really popular in the 1900s in the US

Exons

expressed sequence of DNA; codes for a protein

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; End where DNA was put in: negative end (because DNA is negatively charged); Smallest fragments: move furthest away, Largest fragments: closest to where DNA was put in

Negative control

Group with no response expected (i.e. in gel electrophoresis, we may just use water)

gene

A segment of DNA on a chromosome that codes for a specific trait; approximately 20-22,000

cancer

any malignant growth or tumor caused by abnormal and uncontrolled cell division

gene expression/protein synthesis

The entire process by which proteins are made based on the information encoded in DNA (transcription and translation)

genetics

The scientific study of heredity

genome

the complete instructions for making an organism, consisting of all the genetic material in that organism's chromosomes

genotype

genetic makeup of an organism

phenotype

An organism's physical appearance, or visible traits.

HeLa cells

Cells that are still dividing after over 50 years; were obtained illegally from Henrietta Lacks; have been used in hundreds of research experiements

heterozygous

An organism that has two different alleles for a trait

homozygous

An organism that has two identical alleles for a trait

introns

sequence of DNA that is not involved in coding for a protein

PCR

(polymerase chain reaction) a method used to rapidly make multiple copies of a specific segment of DNA; can be used to make millions of copies of DNA from a very small amount of DNA

protein

An organic compound that is made of one or more chains of amino acids and that is a principal component of all cells

SNP

Variant DNA sequence in which the purine or pyrimidine base of a single nucleotide has been replaced by another such base (also called single nucleotide polymorphism)

STR

short tandem repeats; DNA markers used in DNA profiling (2-10 base pairs repeated many times); about 13; present in introns; almost as unique as a fingerprint (chances of matching 100% with another individual is almost 0)

Transcription

(genetics) the organic process whereby the DNA sequence in a gene is copied into mRNA (happens in the nucleus)

translation

Process by which mRNA is decoded and a protein is produced (happens in the cytoplasm)

variant

a permanent change in the DNA sequence that makes up a gene

Purpose of a micropipettor

to accurately and precisely transfer small volumes of liquid in the microliter range

Purpose of PCR

make copies of DNA

Denaturation

Hydrogen bonds in DNA split (DNA separates); 94 degrees C

Annealing

Binding of primers in PCR, 54 degrees C

Elongation

Taq polymerase adds BPs and extends the DNA; 72 degrees C

restriction enzyme

Enzyme that cuts DNA at a specific sequence of nucleotides

Criminal DNA database

Database of DNA profiles that is maintained by law enforcement agencies

Forensic Index

Database of DNA profiles collected at crime scenes

Offender Index

Database of DNA profiles collected from people who are arrested or convicted of a crime

CODIS

Combined DNA Index System (The FBI's program for linking the federal, state and local DNA profiles in a single database).

Familial searching

Using CODIS and state databases to search for relatives of unknown persons or offenders

How many states collect DNA from convicted felons?

50

How many states collect DNA from juvenile felony offenders?

31

How many states collect DNA for some misdemeanor convictions?

42

All humans typically:

Have the SAME genes, just in different forms

Your genes come from:

half from your mom and half from your dad

To copy DNA, you need the following:

Primers, polymerase, nucleotides, and a DNA template

What is a negative control for?

To make sure the experimental set up is not contaminated

Silent mutation

Does not make a change in the protein

Gel electrophoresis shows:

Different size bands of DNA, if DNA is present in a sample

What are ribosomes responsible for?

Making proteins

Charge of DNA

negative

What is true about micropipettes?

They measure precise volumes of liquid, they measure in microliters, they have specific measurement ranges, and they require a plastic pipette tip

The three types of RNA

ribosomal, transfer, and messenger

If a DNA base change of an A to a T occurs and is copied during replication, is this change necessarily a mutation?

Only if the base change occurs in the coding part of a gene and alters the amino acid sequence of a protein; otherwise no.

A young man develops skin cancer that does not spread to any other tissues; the mutation responsible for the cancer arose in a single skin cell. If he and his wife (who does not have skin cancer) have children after the skin cancer diagnosis, will their children inherit the mutation?

No

What is the maximum number of alleles an individual can have?

2

What is the purpose of ethanol in DNA extraction?

DNA is not soluble in ethanol, so adding ethanol helps separate/isolate the DNA in the sample

What is the difference between the first and second pellets in DNA extraction?

The first pellet is mostly cell debris, and the second is just DNA

Taq Polymerase purpose in PCR

Taq polymerase is used in PCR due to its thermophilic properties. At high temperatures such as the ones used by PCR, other enzymes would denature and lose function.

What are the three differences between DNA and RNA

DNA is double-stranded and RNA is single-stranded; DNA has the sugar dioxyribose and RNA has ribose; DNA has ATCG and RNA has AUCG

Somatic cells

body cells (cheek cells, skin cells, etc); 46 chromosomes (23 pairs)

Gametes

egg, sperm (sex cells); 23 chromosomes

How can we use cells to determine if cancer was inherited or the result of a random mutation?

If the cancer was inherited, the mutation would be present in all cells; if the cancer was the result of a random mutation, it would only be present in the cancerous cells

RNA polymerase role in transcription

Unzips and zips DNA