| A | B |
|---|
| Genetics | branch of biology that studies the ways in which hereditary information is passed from parents to offspring |
| Mendel | monk who investigated inheritance of traits |
| parent (P) generation | original organisms that were crossed |
| first filial (F1) generation | offspring of parent generation |
| second filial (F2) generation | offspring of F1 generation |
| dominant | trait that is always expressed |
| recessive | trait that is hidden in the presence of a dominant trait |
| gene | carries traits on a chromosome |
| alleles | different copes of a gene controlling a certain trait |
| homozygous | alleles for a certain trait in an organism that are the same; HH or hh |
| heterozygous | alleles are different; Hh |
| genotype | genetic makeup of an organisms (HH, Hh, or hh) |
| phenotype | the physical trait that an organism develops as a result of its phenotype (short, tall, etc) |
| Punnett Square | a diagram that shows the possible results of a cross |
| test cross | individual of an unknown genotype is mated with an individual showing the homozygous recessive trait |
| codominance | two dominant alleles are expressed at the same time |
| incomplete dominance | both alleles contribute to the phenotype, but look nothing like either parents |
| dihybrid cross | breeding experiment involving two different traits |
| monohybrid cross | breeding experiment involving one trait |
| linkage group | all of the genes that are on the same chromosome |
| crossing-over | pieces of homologous chromosomes are exchanged during meiosis |
| multiple alleles | traits controlled by more than one allele; such as blood type |
| sex chromosomes | two unmatch chromosomes which determine the gender of an organism |
| autosomes | all homologous chromosomes that are not sex chromosomes |
| X chromosome | rod shaped chromosome; 2=female - 1+Y=male |
| Y chromosome | hook shaped chromosome found in males |
| pedigree | the tracing of traits in families over several generations |
| mutation | sudden change in the structure or amount of genetic material |
| mutants | first individual showing a new trait as a result of a mutation |
| mutagens | factor in the environment that causes mutations |
| Chromosomal mutations | permanent changes in the structure of a chromosome |
| translocation | transfer of a part of a chromosome to an nonhomologous chromosome |
| inversion | piece of a chromosome is rotated |
| addition | piece of a chromosome breaks off and attaches to a homologous chromosome |
| deletion | peiece of a chromosome is broken off causing a loss of genes |
| nondisjunction | addition or loss of a whole chromosome |
| Down syndrome | genetic disorder which results in an extra copy of chromosome 21 |
| Turner syndrome | nondisjunction of sex chromosomes; female with underdeveloped sex characteristics |
| Klinefelter syndrome | male with 2 X chromosomes and 1 Y chromosome; underdeveloped sex organs |
| polyploidy | multiple of the normal chromosome number |
| gene mutations | any change in the sequence of bases along a DNA strand |
| point mutations | substitute one nucleotide for another causing a change in one amino acid |
| frameshift mutation | nucleotide is added or deleted and the whole genetic message is affected |
| selection | choosing an organism with a desirable trait for mating |
| inbreeding | mating of closely related individuals |
| hybridization | mating of non-closely related individuals to produce beneficial alleles into a population |
| karyotyping | arrangement of chromosomes from a photograph to determine inherited traits or disorders |
| amniocentesis | amniotic fluid is removed to determine genetic disorders of a fetus |
| ultrasound | sound waves used to produce an image of the fetus |
| sickle-cell disease | mutation in hemoglobin molecule making it haard for RBCs to deliver O2 |
| Phenylketonuria (PKU) | enzyme cannot break down phenylalanine and caused brain damage |
| Tay-Sachs disease | lack enzyme to break down lipids; lipids build up in brain and cause death |
| Cystic Fibrosis | glands produce a thick mucus that clogs and damages the lungs making it difficult to breathe |
| Huntington Disease | dominant allele that causes a progressive breakdown of brain cells that lead to death |
