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IN How would you define a genetic disorder? Write a list of genetic disorders.

3-04-11

Quiz Notes on genetics

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Case studies of two Genetic Case studies of two Genetic DisordersDisordersOpen your book to page 496Read essay

Phenotype and GenotypePhenotype and Genotype

Notes:Notes:Phenotype---observable traits of an

organism. Blood type, eye color, petal color Genotype decides phenotype Environmental factors can influence how

genetic information produces a phenotype. Height (based on nutrition and genotype)

Genotype--the genetic plan that is found in cells of organisms. Stored in DNA(deoxyribonucleic acid)

moleculesFound inside cell, nucleus

Packed inside the nucleus are chromosomes(Humans=46;23mom+23 dad)DNA molecules organized around proteins

Gene-a small piece of genetic information

Allele-one of two or more possible forms of a gene.Each affects the hereditary trait somewhat differently. S=straight ears s=floppy ears Organisms that reproduce sexually

receive one allele from each parentHeterozygous-have two different

alleles Ss

Homozygous-having two of the same alleles SS or ss

Dominant trait- presents itself whether the organism is homozygous dominant (SS) or heterozygous (Ss) SS=Straight earsSs=Straight ears

Recessive trait- presents itself only when the organism is homozygous recessive (ss) ss=Floppy ears

Independent assortment --traits are independent of each other. More combinations are possible Opposite to sex-linked Genes for traits are on different

chromosomes

5. In cocker spaniels, black B is dominant over red b. Solid color S is dominant over white spotting s. A red male was mated to a black-and-white female. They had five puppies, as follows: one black, one red, one black and white, and two red-and-white.

A. What genetic principle explains the phenotypes of these offspring?

B. Write a one or two paragraphs to describe how that principle worked in this cocker spaniel family. Include the following terms; gene, phenotype, dominant trait, recessive trait, chromosome, allele, genotype

Case studies of two genetic disodersHuntington’s disease- a dominant

genetic disorder that causes degeneration of the central nervous system. Symptoms occur after 35 NO cure Disease causes the brain and nerves to

slowly shutdown for up to 15 years, then person dies

Genotype Hh or HH

Cystic fibrosis -- a recessive genetic disorder that affects the respiratory system. Symptoms show at birth Lungs are clogged with thick mucus Affects digestive system as well because of

mucus Possibilities range between races Genotype cc NO cure, person usually dies at a young age

However, antibiotics, vapor therapy, and chest thumping help

Other genetic disorders to research: Down syndrome Sickle-cell

Would you test to see if you and your partner carry genetic disorders?

What are the advantages of knowing you have alleles for genetic disorders?

What are the disadvantages of knowing you have alleles for genetic disorders?