Genetics Or…..Who’s Yo Daddy?!?

Heredity- passing of characteristics ( traits) from parent to offspring. Traits- examples: shape of nose, size of lips, dimples Traits- passed on in packets of DNA called genes.

Genes All genes are not created equal!! Stronger genes for the same trait are called “dominant” Weaker genes for the same trait are called “recessive” Abbreviate capital letter for dominant, lower case for recessive. Example.

What you see is what you got?!? What you have inside your chromosomes is your “genotype” Example: DD or 2 dimple genes The expression of your DNA (what you see) is called your “phenotype” Example: Actual Dimples.

Blending Not all traits are dominant/ recessive, some “blend” both genes. Example: size of eyes- large and small make medium sized.

Blood Typing Co-dominance 3 different alleles: A, B, O Create 4 different blood types: A, AB, B, O Type O is recessive Each parent “donates” one blood type allele to offspring Create antigens on each red blood cell – how your body knows it’s your blood

Which alleles are there? Blood type A, could be: _____ or _____ Blood type B, could be ______ or _____ Blood type AB: ______ Blood type O: _______

Blood Typing Rh factor – Rhesus (monkey) factor Rh+ dominant, Rh- recessive Each parent donates one to offspring, either + or -

Universal donor: type O No antigens present Universal recipient: AB+ Already has antigens for both, will not create antibodies and fight off any type

Sex Chromosomes What makes you male or female? Females have 2 X chromosomes- XX Males have 1X and 1 Y- XY. X chromosome is larger, more genes on it

What can mom pass on? What can dad pass on? So who determines the sex of the baby?

Karyotype

Allelle

Writing prompt DNA tests have proven that “John Doe” is the father of a child that looks nothing like him or his other 2 children. Using terms learned in class, write a paragraph explaining how this is possible.