Heredity and Chromosomes Chapter 14 Section 1 Quick

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Heredity and Chromosomes Chapter 14 Section 1

Heredity and Chromosomes Chapter 14 Section 1

Quick Review n We have 46 Chromosomes in all of our cells except our

Quick Review n We have 46 Chromosomes in all of our cells except our gametes n The 46 Chromosomes come in 23 pairs – Half from mom, half from Dad – Each chromosome in a pair contains the same general information – Pairs are said to be “HOMOLOGOUS”

More on Chromosomes There are 22 Pairs of AUTOSOMES and 1 pair of SEX

More on Chromosomes There are 22 Pairs of AUTOSOMES and 1 pair of SEX CHROMOSOMES n A picture of all chromosomes contained in a cell is called a KARYOTYPE n

Key Notes about Chromosomes All autosomes are identified by numbers (IE Pair #1, Pair

Key Notes about Chromosomes All autosomes are identified by numbers (IE Pair #1, Pair #2) n Sex Chromosomes are identified by the letters “X” and “Y” n – Women have 2 “X” Chromosomes – Men have 1 “X” chromosome and 1 “Y” chromosome – There is roughly a 50/50 chance of giving birth to either a boy or a girl – The man is responsible for the gender of a child

Pedigrees We already know traits are passed down from parents to offspring n A

Pedigrees We already know traits are passed down from parents to offspring n A PEDIGREE is a chart used to display the inheritance of traits over generations n Handy in determining likely hood of children inheriting diseases or traits n

Pedigree : Whirling Family

Pedigree : Whirling Family

Inheritable Disorders n Some traits and disorders are found on AUTOSOMES – IE: Achondroplasia,

Inheritable Disorders n Some traits and disorders are found on AUTOSOMES – IE: Achondroplasia, Albinism, Cancer n Some traits are found only on Sex chromosomes – IE: Hemophelia n Despite genetics, environment can play a HUGE role in the outcome of certain traits