Chromosomal Basis for Inheritance General Biology SUNY Orange at S. S. Seward Institute

0.5 mm Parent Bud (a) Hydra

Chromosomes in Motion video

22 + XX 22 + X (b) The X-0 system

76 + ZW 76 + ZZ (c) The Z-W system

(d) The haplo-diploid system 32 (Diploid) 16 (Haploid) (d) The haplo-diploid system

0.5 mm Parent Bud

Test cross -

QV = 38 extra credit: Where’s U? Chromosomal Mapping The following genes have been determined to have recombination rates as follows: QS = 24 RV = 2 SR = 12 QR = 36 Draw the gene map. TS = 4 QT = 20 QV = 38 extra credit: Where’s U?

Epigenetics is the study of heritable changes in gene expression or cellular phenotype caused by mechanisms other than changes in the underlying DNA sequence refers to functionally relevant modifications to the genome that do not involve a change in the nucleotide sequence PBS video

Calico Cat Genetics

Aneuploidy Aneuploidy – an abnormal number of chromosomes Usually the result of non-disjunction Can be extra or missing chromosomes

Sex Linked Aneuploidy XXY – Kleinfelter Syndrome XO – Turner Syndrome XYY - XXX -

Genomic Imprinting For some traits, expression will depend on whether the allele is inherited from the male or female parent Identified in 2-3 dozen traits in mammals Often genes controlling development Mechanism is probably DNA methylation

Epigenetics epigenetics is the study of heritable changes in gene expression or cellular phenotype caused by mechanisms other than changes in the underlying DNA sequence

Organelle Genes a.k.a – extranuclear genes Chloroplasts and mitochondria have DNA and genes

Essay What is epigenetics and why is it important?