Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings PowerPoint Lectures for Biology: Concepts and Connections, Fifth Edition – Campbell, Reece, Taylor, and Simon Lectures by Chris Romero Chapter 9 Patterns of Inheritance

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 9.0 Genetics - the science of A common genetic - will produce offspring with similar Purebred dogs - show less

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 9.1 Gregor Mendel - hypothesized that there are alternative - experimental genetics - Mendel crossed pea plants that differed in - traced traits from generation to

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 9.2 Mendel's law of segregation - the inheritance of - there are alternative forms - accounts for variation in

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings For each characteristic, an organism inherits: - two – Homozygous: two – Heterozygous: two

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings If the two alleles of an inherited pair differ: The dominant allele - determines the The recessive allele - has no noticeable effect on the

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings The law of segregation - a sperm or egg carries only one 9.3 Phenotype - expressed Genotype - actual

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 9.4 Homologous chromosomes - bear the two alleles for - alternative forms of a gene - are located at - on homologous 9.5 Genetic traits in humans - can be tracked through

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings CONNECTION 9.6 Some human genetic disorders follow simple Mendelian - Recessive disorders - can be carried unnoticed by - range in - from mild ( - to severe (

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Dominant disorders - some serious, but - lethal conditions

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings CONNECTION 9.7 New genetic technologies - Identifying tests can distinguish parental carriers of Fetal testing 1. Amniocentesis - removal of ___________________ to test for genetic

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 2. Fetal imaging - Ultrasound imaging uses sound waves to produce Ethical consideration: How will genetic testing Video: Ultrasound of Human Fetus 1 Video: Ultrasound of Human Fetus 1

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 9.8 Complete dominance - dominant allele has same phenotypic effect whether Incomplete dominance - heterozygote exhibits characteristics intermediate between

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 9.9 Many genes have more than Ex: human ABO – involves – AB blood group an example of both alleles are expressed in

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 9.10 Polygenic inheritance - the additive effects of two or more genes - Ex: human - controlled by at least

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings SEX CHROMOSOMES AND SEX-LINKED GENES 9.11 Many animals have a pair of chromosomes to determine sex - human male is - the Y chromosome has genes for - human female is - absence of a Y chromosome allows

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 9.12 Sex-linked genes - for characteristics ( - located on either sex - in humans, refers to a gene on

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings CONNECTION 9.13 Sex-linked disorders In humans, recessive sex-linked traits: - expressed much more frequently in Most known sex-linked traits are caused by genes (alleles) on Examples: - -