Genetics and Genetic Diseases Genetics Study of inheritance
- Slides: 25
Genetics and Genetic Diseases
Genetics Study of inheritance and human disease p 1860’s – Gregor Mendel p Gene = DNA RNA Proteins (enzymes) permit specific biochemical reactions to occur p Genes determine the structure and function of the human body p
Chromosome p Chromosomes are made of chromatin (DNA)
Human Genome Project p Genome – entire collection of genetic material in a cell p 2001 – rough draft published n n 30, 000 genes 1% carries genes, rest is filler Genomics – analysis of genome p Proteomics – proteins encoded by genes, goal is to understand role of each protein p
Ideogram p Simple cartoon of chromosome n n n P-arm – shorter segment Q – arm – longer segment Bands – show landmarks
Chromosomes 46 chromosomes in a cell, 23 pair p 22 pair – autosomes (body cells) p 23 rd pair – sex chromosomes p n n n XX, XY Undergo meiosis, produce sex cells (gametes) Sperm meets egg = zygote
Genetic Variation p Independent assortment Crossing over p Random p fertilization
Gene Expression – Mendel Complete Dominance Dominant – CC, trait seen p Recessive – cc, trait only seen if both alleles are recessive p CC – homozygous dominant p Cc – heterozygous p cc – homozygous recessive p p Example: Albinism
Gene expression p Codominance – both alleles are dominant n p Incomplete dominance – hybrid n p Ex – blood type A, B, O, AB Pink flowers Sex linked – non-sexual trait carried on X or Y chromosome, sometimes called xlinked since X chromosome is largest n Hemophilia, color blindness
Genetic Mutations p Change in DNA, genetic code n n p Can occur spontaneously Mutagens – cause mutations Carcinogens – cause cancer, viruses Damage to chromosome, deletion can be beneficial
Mitochondrial DNA p p Powerhouse of cell with own circle of DNA Inheritance occurs only through the mother n n sperm mitochondria do not survive during fertilization Codes for only a few important enzymes n carry mutations that produce disease p p p Leber’s hereditary optic neuropathy Parkinsons Alzheimers
Mechanisms of Genetic Disease Single gene diseases p Genetic predisposition – not solely caused by inheritance, but environmental p Non-disjunction – failure of chromosomes to separate p n n Trisomy – triplet of chromosomes (Down syndrome) Monosomy – single chromosome only (Turner syndrome)
Single gene diseases p Cystic fibrosis n n n Recessive Chromosome 7 CFTR gene regulates transfer of sodium ions across cell membrane and serves as chloride ion channel
Phenylketonuria - PKU Recessive p Fail to produce enzyme phenylalanine hydroxylase p n n Converts aa phenylalanine into tyrosine Lack of enzyme results in accumulation and presence of phenylketone in urine which destroys brain tissue. Identified at birth Diet restrictions
Chromosomal diseases Down syndrome, Trisomy 21 p Not inherited, result of nondisjunction p Characterized by p n n n Varying range of mental retardation Distinctive facial appearance Enlarged tongue…
Klinefelter syndrome Nondisjunction of sec chromosomes – XXY p Characteristics p n n n Long legs Enlarged breasts Low intelligence…
Turner Syndrome XO, monosomy female p Characteristics include: p n n n p failure of sex organs maturing dwarfism or short stature cardiovascular defects… Can be treated with hormone therapy, surgery
Prevention and treatment of genetic diseases p Genetic counseling – professional consultation n p Help to determine risk Help evaluate whether offspring have a genetic disorder Offer advice on treatment, care Tools n n n Pedigree Punnett square karyotype
Pedigree p Shows relationships in a family over several generations
Punnett square p Box used to determine the probability of inheriting genetic traits n n Monohybrid dihybrid
Karyotype Used to find chromosomal disorders p Use a sample of cells (cheek, wbc) p Cells in metaphase are stained and photographed p Chromosomes cut and arranged according to size p
Amniocentesis p Fetal cells floating in amniotic fluid are collected using a LARGE syringe
Chorionic Villus Sampling Cell from chorionic villi are collected from area surrounding embryo p Cells are grown in petri dishes, then analyzed p
Treating Genetic Diseases No cure, but some can treat symptoms p Gene therapy p n n Gene replacement – replace abnormal with normal Gene augmentation – normal cells are introduced and add normal proteins
- Chapter 22 genetics and genetically linked diseases
- What causes genetic diseases
- The founder effect
- Genetic programming vs genetic algorithm
- Genetic programming vs genetic algorithm
- Genetic drift
- What is the difference between genetic drift and gene flow
- Human inheritance modern genetics answer key
- Modern genetics human inheritance answer key
- Modern genetics human inheritance answer key
- Molecular genetics section 1 dna the genetic material
- Genetics is the study of heredity and variation.
- Chapter 7 extending mendelian genetics study guide answers
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- Section 19-3 diseases caused by bacteria and viruses
- Define a primary skin lesion and list three types
- Chapter 6 musculoskeletal system diseases and disorders
- Chapter 24 sexually transmitted diseases and hiv/aids
- Chapter 21 mental health diseases and disorders
- Chapter 17 reproductive system diseases and disorders
- Chapter 15 nervous system diseases and disorders
- Onychomycosis milady
- Chapter 8 skin disorders and diseases
- Nail disease
- Icd 10 morbus hansen