BJU Press Biology Chapter 9--Advanced Genetics

gene pool

the sum of all the alleles that all individuals of a population of organisms can conceivable possess

variation

the range of genotype differences between individuals from the same gene pool

gene flow

the ebb and flow of genetic material in a population

allele frequency

how often an allele shows up in a gene pool

plasmids

small, circular DNA molecules that function like chromosomes

mutations

mistakes in copying or decoding DNA

genetic equilibrium

when the allele frequency is stable in large populations

genetic drift

a change in the allele frequency based on random events

bottleneck effect

when a large population dies and the survivors have a dramatically different gene pool and allele frequency

founder effect

when a small population moves to a new area and the allele frequency changes as the small population begins a new population

mutagen

a physical or chemical substance that changes the genetic structure

point mutation

when just one nucleotide base changes in the DNA chain

germ mutations

mutations that occur in gametes or in cells that produce gametes

somatic mutations

mutations in cells that don’t make gametes

frameshift mutation

if a nucleotide base is added or deleted, the entire codon shifts

telomeres

the tips of chromosomes that usually do not participate in crossing over

telomerase

an enzyme that ensures that the telomeres remain fairly stable during meiosis

inversion

when a segment of a chromosome may break off and reattach in the same position upside down

nondisjunction

the failure of the chromosome to separate

polyploidy

exhibited by cells with three or four full sets of chromosomes

euploidy

complete chromosome sets

aneuploidy

missing or extra chromosomes

tumor

an abnormal mass of cells caused when a mutated cell begins to divide uncontrollably

benign tumor

don’t spread to other parts of the body

malignant tumors

can metastasize

metastasize

spread to other parts of the body

chemotherapy

uses chemicals to poison and disrupt cell processes in abnormal cells so they can’t divide, killing the cells and shutting down their reproduction

radiation therapy

uses high doses of energetic radiation to burn cancer cells that slow down or stop their growth

carcinogens

substances that increase someone’s risk of cancer

genomics

the study of genomes

genomes

an organism’s full set of genetic information coded by its DNA

genetic engineering

the process of deliberately manipulating the genes within an organism in ways other than natural process like reproduction

restriction enzyme

an enzyme used to cut DNA in specific places into pieces for study

sequencing DNA

determining the order of nucleotides in an organism’s DNA

polymerase chain reaction

the process of making multiple copies of a gene under study that starts by separating the DNA strand (by heating up), complementary primers are added and bond to the sticky ends to jumpstart replication once the DNA cools

recombinant DNA

customized DNA

genetically modified organism

an organism that has undergone genetic engineering

transgenic organisms

organisms that contain genes from other kinds of organisms

gene therapy

a type of genetic engineering used to relieve a genetic disorder or disease

the process of gene therapy

vectors are sent to deliver recombinant DNA, inserts its genetic information, therapeutic DNA produces desired effect

DNA fingerprinting

the process of using DNA to identify individuals

gel electrophoresis

the process in which DNA fragments are applied to a gel-covered plate and an electrical current is applied. the DNA fragments sort as they travel down the plate from longest strands to shortest strands.