Honors Bio

Biotechnology

use of technology to alter genetic makeup of living organisms to produce useful products

Genetic engineering

direct modification of an organism DNA to ensure expression of a desired trait

Recombinant DNA

DNA artificially created by combining genetic material from different sources

Genome

complete set of DNA including all genes in an organism

Human Genome Project

first complete mapping of the entire human genome completed in 2003

ENCODE project

research project to interpret functional elements of the human genome sequence

1000 Genomes Project

effort that sequenced genomes from many individuals to study human variation

Gene map

diagram showing positions of genes on a chromosome

Restriction enzymes

enzymes that cut DNA at specific recognition sequences

Restriction site

specific DNA sequence where a restriction enzyme cuts

Sticky ends

single stranded overhangs that allow DNA fragments to bond with complementary pieces

DNA ligase

enzyme that connects DNA fragments by forming bonds in the backbone

Polymerase chain reaction

laboratory method used to rapidly copy specific DNA sequences without cells

DNA amplification

process of producing many copies of a DNA segment

Gel electrophoresis

technique that separates DNA fragments by size using an electric field

DNA fingerprinting

identification method based on unique DNA fragment patterns

Personal genome sequencing

determining the full DNA sequence of an individual to assess traits and disease risk

Gene cloning

production of many identical copies of a gene or DNA segment

Transformation

process of introducing foreign recombinant DNA into a host cell

Plasmid

small circular bacterial DNA used as a vector for gene insertion

Vector

carrier DNA molecule used to transfer genetic material into a cell

Bacterial transformation

genetic modification of bacteria to produce specific proteins

Insulin production by bacteria

process where bacteria are engineered to make human insulin for medical use

Gene therapy

treatment that adds or edits genes to correct genetic disorders

CRISPR

precise gene editing system that can cut and repair DNA sequences

Stem cells

undifferentiated cells capable of developing into specialized cell types

Selective breeding

human directed breeding to enhance desired traits

Hybridization

crossing genetically different individuals to produce offspring with combined traits

Mutation

change in the nucleotide sequence of DNA

Somatic mutation

mutation in body cells that is not inherited by offspring

Germ line mutation

mutation in reproductive cells that can be passed to offspring

Mutagen

environmental factor or chemical that increases mutation rate

Replication error

mistake during DNA copying that can cause mutations

Gene mutation

alteration in the DNA sequence of a single gene

Chromosome mutation

change affecting chromosome structure or number

Point mutation

substitution of one nucleotide for another

Frameshift mutation

insertion or deletion that alters the reading frame of codons

Insertion mutation

addition of one or more nucleotides into DNA

Deletion mutation

removal of one or more nucleotides from DNA

Duplication mutation

chromosome segment copied resulting in extra genetic material

Translocation mutation

exchange of segments between nonhomologous chromosomes

Nondisjunction

failure of chromosomes to separate properly during cell division

Aneuploidy

abnormal number of chromosomes in a cell

Trisomy

condition with three copies of a chromosome

Trisomy 21

genetic condition caused by three copies of chromosome 21

Down syndrome

disorder caused by trisomy 21 due to nondisjunction

Pedigree

diagram used to trace inheritance of traits through a family

Pedigree notation

standardized symbols used to represent individuals and relationships

Autosomal recessive trait

trait expressed only when two recessive alleles are present

Autosomal dominant trait

trait expressed when at least one dominant allele is present

Sex linked recessive trait

trait carried on X chromosome often affecting males more

Carrier

individual with one recessive allele who does not show the trait

Generation skipping

pattern where recessive traits appear after one or more unaffected generations

Diploid cell

cell containing two sets of chromosomes one from each parent

Gamete

haploid reproductive cell such as egg or sperm

Haploid cell

cell with one set of chromosomes

Gene

segment of DNA that codes for a protein

Allele

different form of a gene

Homologous chromosomes

chromosome pair with the same genes in the same order

Purebred organism

organism whose ancestors share the same genetic traits

Cross

mating between two organisms to study inheritance

Parental generation

original parents in a genetic cross

First filial generation

first generation of offspring from parental cross

Second filial generation

offspring from crossing individuals of the first generation

Homozygous

having two identical alleles for a gene

Heterozygous

having two different alleles for a gene

Dominant allele

allele that expresses its trait whenever present

Recessive allele

allele expressed only when dominant allele is absent

Genotype

genetic constitution of an organism

Phenotype

observable physical or functional traits

Law of dominance

principle that dominant alleles mask recessive alleles

Law of segregation

allele pairs separate during gamete formation so each gamete receives one

Law of independent assortment

alleles of different genes assort independently during gamete formation

Punnett square

grid used to predict possible genotypes of offspring

Monohybrid cross

cross involving one trait

Dihybrid cross

cross involving two traits simultaneously

Probability in genetics

likelihood that a specific genotype or phenotype will occur

Incomplete dominance

inheritance where heterozygote shows intermediate phenotype

Codominance

inheritance where both alleles are fully expressed in heterozygote

Multiple alleles

gene with more than two possible allele forms in a population

Blood type system

inheritance determined by A B and i alleles

Agglutinogens

antigens present on surface of red blood cells

Antibodies

proteins in plasma that recognize and attack foreign antigens

Universal recipient

individual with AB blood type able to receive all blood types

Universal donor

individual with O blood type able to donate to all blood types