COMPLEX INHERITANCE and COMMON GENETIC DISORDERS Fill-in-blank Notes Use your text to read and learn about each topic, filling in the blanks below. Add pictures, examples, page numbers, or additional notes as needed. p. 296-298 Recessive Disorders: most human disorders are recessive, so individuals must have two recessive alleles to show the disorder. Examples of Recessive disorders: Cystic fibrosis – Albinism Tay-Sach’s disease – Galactosemia PKU (phenylketonuria) - inability to breakdown phenylalanine in blood; tested with foot prick test shortly after birth. Can cause mental impairment and lack of normal skin pigmentation. Babies and children with it must maintain a strict diet low in this amino acid. Discuss some dangers of inbreeding – p. 298-Dominant disorders: some human disorders due to dominant alleles, some non-lethal. Just because a gene is dominant does NOT mean that there is more of it in a population. In fact, lethal dominant genes are much less common than lethal recessive genes because it affects anyone who gets it, so offspring may not survive long enough to reproduce. In this way it reduces the number of lethal genes in the population. Examples: Huntington’s disease – Achondroplasia – Polydactyly – extra fingers or toes – usually underdeveloped appendages
COMPLEX INHERITANCE and COMMON GENETIC DISORDERS Fill-in-blank Notes Use your text to read and learn about each topic, filling in the blanks below. Add pictures, examples, page numbers, or additional notes as needed. p. 296-298 Recessive Disorders: most human disorders are recessive, so individuals must have two recessive alleles to show the disorder. Examples of Recessive disorders: Cystic fibrosis – Albinism Tay-Sach’s disease – Galactosemia PKU (phenylketonuria) - inability to breakdown phenylalanine in blood; tested with foot prick test shortly after birth. Can cause mental impairment and lack of normal skin pigmentation. Babies and children with it must maintain a strict diet low in this amino acid. Discuss some dangers of inbreeding – p. 298-Dominant disorders: some human disorders due to dominant alleles, some non-lethal. Just because a gene is dominant does NOT mean that there is more of it in a population. In fact, lethal dominant genes are much less common than lethal recessive genes because it affects anyone who gets it, so offspring may not survive long enough to reproduce. In this way it reduces the number of lethal genes in the population. Examples: Huntington’s disease – Achondroplasia – Polydactyly – extra fingers or toes – usually underdeveloped appendages
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