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Patho chp 5
Term | Definition |
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mitosis | A type of indirect cell division that occurs in somatic cells and results in the formation of two daughter nuclei containing the identical complements of the number of chromosomes characteristic of the somatic cells of the species |
meiosis | The division of a sex cell as it matures, so that each daughter nucleus receives one half of the number of chromosomes characteristic of the somatic cells of the species |
karyotype | The total chromosomal characteristics of a cell; or the micrograph of chromosomes arranged in pairs in descending order of size |
pedigree | A systematic presentation, such as in a table, chart, or list, of an individual’s ancestors that is used in human genetics in the analysis of inheritance |
genotype | The entire genetic constitution of an individual, as determined by the particular combination and location of the genes on the chromosomes; or the alleles present at one or more sites on homologous chromosomes |
in situ | In the natural or normal place; or something, such as cancer, that is confined to its place of origin and has not invaded neighboring tissues |
phenotype | The complete physical, biochemical, and physiologic makeup of an individual, as determined by the interaction of both genetic makeup and environmental factors |
The genome | the gene complement of an organism |
Genomic mapping | method used to assign genes to particular chromosomes or parts of a chromosome |
The most important methods | family linkage studies, gene dosage methods, and hybridization studies |
Linkage studies | assign a chromosome location to genes based on their close association with other genes of known location |
Dosage studies | involve measuring enzyme activity to determine if both members of a gene pair are present and functioning normally |
Hybridization studies | involve the fusion of human somatic cells with those of a different species to study gene location on chromosomes |
Recombinant DNA studies | involve the extraction of specific types of mRNA used in the synthesis of complementary DNA strands |
The complementary DNA | strands, labeled with a radioisotope, bind with the genes for which they are complementary and are used as gene probes |
Genetic engineering | has provided the methods for manipulating nucleic acids and recombining genes (recombinant DNA) into hybrid molecules that can be inserted into unicellular organisms and reproduced many times over |
As a result, proteins | that formerly were available only in small amounts (e.g., human insulin) can now be made in large quantities once their respective genes have been isolated |
Deoxyribonucleic acid fingerprinting | relies on recombinant DNA technologies and those of genetic mapping and often used in forensic investigations |
A newer strategy for management of genetic disorders | focuses on gene silencing by using ribonucleic acid interference (RNAi) technology to stop genes from making unwanted disease proteins |