Genneeticssscscsscsc

. Define genotype: genes of an individual that characterize a specific trait. alleles: genes having the same position on a pair of chromosomes and affecting the same trait. dominant allele: represented by an uppercase letter, represents a specific trait. recessive allele: represented by the same lowercase letter as the dominant. homozgous dominant: The genotype EE or capital letters with both dominant alleles. homzygous recessive: represented by ee or two lowercase both recessive alleles. heterozygous: represented by Ee, one dominant and one recessive allele. phenotype: specific characteristics developed by an individual. 2. What is the difference between genotype and phenotype? Genotype is the formation of genes and chromosomes to make the phenotypes, which are characteristics caused by the genotypes. 3. What are the three possible genotypes and the two possible phenoyptes for a characteristic that is controlled by two alleles, one being dominant and the other recessive? EE, Ee, ee, E for unattached earlobes, e for attatched, if there is an E in any part of the genotype, then the person will have unattached earlobes. 4. Write down the question and answer for questions 1,2,3 on page 423. 1) a) WW b) WW, Ws, WS, Ss c) Tt, tT d) Tt, gT, tg e) AB, Ab, Aa, Ba, ba 2) a) genotype b) gamete c) gamete d) genotype 3) a) EeSs b) eeSS 5. Define the following genetic disorders on pp. 431 to 432 Make sure you describe the function of the gene that is mutated and what happens with the mutated gene. Tay-sachs disease: the result from a lack of the enzyme hexosaminidase A. Lysosomes build up in many cells mostly in the brain which accounts for the onset of sumptoms and the progressive deterioration of brain functions. cystic fibrosis: cloride ions fail to pass through the plasma membrane channel protein in the cell. The lack of water causes abnormally thick mucus in the lungs. It clogs pancreatic ducts prevent digestive system. Phenylketonuria: autosomal recessive metabolic disorder that affects nervous system development. The indivuals affected lack an enzyme that is needed for the metabolism and it makesthe amino acid appear in there blood. sickle-cell disease: the red blood cells are not biconcave disks like normal ones. This is caused by abnormal hemoglobin which differs by one amino acid. The abnormality causes the molecules to stack up and form insoluble rods. marfan Syndrome: caused by a defect in fibrillin. This defect causes the infected people to have dislocated lenses, long limbs and fingers, and a caved in chest. The aorta wall is weak and may burst randomly. huntintongons's disease: neurological disorder that leads to progressive degeneration of brain cells. This is caused by the mutated copy of the gene for protein called Huntington.