* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Dr. Sinan Bahjat MBCh.B., M.Sc., FIBMSL1
Non-coding DNA wikipedia , lookup
Behavioural genetics wikipedia , lookup
Polymorphism (biology) wikipedia , lookup
Nutriepigenomics wikipedia , lookup
SNP genotyping wikipedia , lookup
Minimal genome wikipedia , lookup
Genome evolution wikipedia , lookup
Y chromosome wikipedia , lookup
Gene expression programming wikipedia , lookup
Gene expression profiling wikipedia , lookup
Pharmacogenomics wikipedia , lookup
Point mutation wikipedia , lookup
Human genetic variation wikipedia , lookup
Biology and consumer behaviour wikipedia , lookup
Polycomb Group Proteins and Cancer wikipedia , lookup
Site-specific recombinase technology wikipedia , lookup
Vectors in gene therapy wikipedia , lookup
Medical genetics wikipedia , lookup
Public health genomics wikipedia , lookup
Skewed X-inactivation wikipedia , lookup
Genetic engineering wikipedia , lookup
Therapeutic gene modulation wikipedia , lookup
Neocentromere wikipedia , lookup
Genomic imprinting wikipedia , lookup
Epigenetics of human development wikipedia , lookup
History of genetic engineering wikipedia , lookup
X-inactivation wikipedia , lookup
Population genetics wikipedia , lookup
Quantitative trait locus wikipedia , lookup
Genome (book) wikipedia , lookup
Artificial gene synthesis wikipedia , lookup
Hardy–Weinberg principle wikipedia , lookup
Designer baby wikipedia , lookup
Genetic drift wikipedia , lookup
Dr. Sinan Bahjat M.B.Ch.B., M.Sc., F.I.B.M.S. L.1 Definitions Genetics Medical genetics is concerned with the study of human biological variation and its relationship to health and disease. Chromosome A chromosome is a long and stringy aggregate of genes that carries heredity information (DNA) and is formed from condensed chromatin. A non-duplicated chromosome is singlestranded and is comprised of a centromere region that connects two arm regions. The short arm region is called the ( p ) arm and the long arm region is called the ( q ) arm. Genes genes are segments of DNA located on chromosomes. Genes exist in alternative forms called alleles. Genes contain the codes for the production of specific proteins. The information contained within DNA is first transcribed in a process called (DNA transcription). This process takes place within the nucleus of our cells. Actual protein production takes place in the cytoplasm of our cells through a process called (translation). Allele An allele is an alternative form of a gene (one member of a pair) that is located at a specific position on a specific chromosome. Genotype The genotype of an organism is the inherited instructions it carries within its genetic code (i.e. the genetic makeup of an organism). Phenotype A phenotype is the composite of an organism's observable characteristics or traits, such as its morphology, development, biochemical and physiological properties. Karyotype It is a picture of chromosomes that are about to divide. Mendel's Law of Segregation Principle This law states that allele pairs separate or segregate during gamete formation, and randomly unite at fertilization. There are four main concepts related to this principle. A gene can exist in more than one form. Organisms inherit two alleles for each trait. When gametes are produced (by meiosis), allele pairs separate leaving each cell with a single allele for each trait. When the two alleles of a pair are different, one is dominant and the other is recessive. Example The gene for seed color in pea plants exists in two forms. There is one form or allele for yellow seed color (Y) and another for green seed color (y). In this example, the allele for yellow seed color is dominant and the allele for green seed color is recessive. When the alleles of a pair are different (heterozygous), the dominant allele trait is expressed and the recessive allele trait is masked. Seeds with the genetic makeup of (YY) or (Yy) are yellow, while seeds that are (yy) are green. Summary Medical Genetics is concerned with the study of human biological variation and its relationship to health and disease. Definitions: Chromosome, Gene, Allele, Genotype, Phenotype, and Karyotype. Mendel’s law of segregation: This law states that allele pairs separate or segregate during gamete formation, and randomly unite at fertilization. A gene can exist in more than one form. Organisms inherit two alleles for each trait. When gametes are produced (by meiosis), allele pairs separate leaving each cell with a single allele for each trait. When the two alleles of a pair are different, one is dominant and the other is recessive. Thank You