Ch.12 Powerpoint notes

Bellwork questions: answer these in your notebooks (you may use your text) * * * *

Inheritance patterns and Human Genetics

* Human chromosome review * ____ pairs * 1-22 = ______* 23rd pair = _____ chromosome * What are the ____ sex chromosomes? * Female: ______* Male: ______* ____ chromosome contains ____ gene * SRY: ______- gene coding for production of male gonads (testes)

Sex-linked genes and traits * Sex-linked traits: ______* ____ chromosome much larger = many more gene than _____ * Examples: – SRY (______) – Color blindness (______) – ______(X-linked) * Linked genes * ______: pairs of genes that tend to be inherited together * Genes ______to each other on ______* Example * If crossing over occurs, ______are likely to be inherited together * ______less likely

Mutations * ______in nucleotide base sequence * ______cell mutation: ______* does ______affect ______* can be ______to offspring * ______cell mutation: ______* ______affect organism * ______mutations: can cause ______(usually before birth) * Mutations * Chromosomes can be: * ______* ______around (inverted) * Moved to the wrong chromosome * ______bases (& sequences) can be: * ______* ______* Substituted * Etc.

* Mutations * Two main categories: * Chromosomal (affect chromosome) * Nondisjunction: ______* Down Syndrome

2. Gene (affect DNA sequence) * ______: affects one codon and as a result, all codons downstream are changed (shifts the reading frame) * ATC/GTA/GCT/GCT/ATT * ATC/GTT/AGC/TGC/TAT/T

12-2 Human genetics * Pedigree: diagram that shows how a ______is ______over several ______

* ______used to: – See patterns of ______– See if trait is ______or ______– ______or recessive – Genetic traits and ______* Some traits have a ______with two or more alleles * Blood type * Cystic fibrosis * Most human traits are ______: characters influenced by ______genes * Skin color; 3-6 genes * Genetic ______and ______* ______characters: influenced by ______and genes * Skin color exposed to sunlight * ______* Breast cancer * Diabetes * Heart disease

Multiple alleles * Genes have ______than ______alleles – ______blood type – Incomplete dominance – ______is an intermediate phenotype

X-linked traits * More common in males (x-linked recessive) – Males inherit _____ from ______and no other – ______possibility of heterozygous o colorblindness * ______allele traits – Single ______of a ______controls these traits – <200 human traits o Huntington’s Disease o ______dominant o Symptoms @30-40 y. o.

Detecting genetic disease * Genetic screening: examination of a person’s ______information – Need ______* ______: removal of amniotic fluid surrounding fetus * 14th-15th week * Chorionic villi sampling: sample of chorion villi (______developing embryo) * ______

* Open text to page 246 * Copy table in your notes * You only need the disorder, pattern of inheritance, and brief description of symptoms Disorder Pattern of Inheritance Description of Symptoms