Genetics: Inheriting Traits

Chromosomes Chromosomes ________________ ________________ ____. You have ___sets, from chromosome ____-____ (______ total)

Genes and Traits Genes are ___________________ __________ of chromosomes that code for a _________. (instruction manuals) Traits ___________________ ___________________ ___________________ Types of traits: 1)_______________ 2)_______________ 3)_______________ Mr. Emery?

Question 1)How many different chromosomes do you have? 2)How many sets of these chromosomes do you have? 3)What are chromosomes made of?

Genotypes vs. Phenotypes Genotype: ____________________________________ _____. They are expressed in letters and come in pairs (WW, Ww, ww). Phenotype: ____________________________________ _________________________________ (widows peak) [from Greek phaino- shining, from phainein to show] The individual letters are called alleles. (W) or (w) (probably not on exam)

Dominant vs. Recessive Traits Dominant traits: When two different traits are paired (widows peak vs. straight hairline) ____________________________________ _______. Dominant traits are usually expressed genetically with an upper-case letter of ___________________________________ (W)

Dominant vs.. Recessive Traits Recessive traits: are __________________ when paired up with a dominant trait. Recessive traits are expressed genetically with a lower-case letter of the ____________________________________ ____________________________________. –Straight hairline is expressed with ( w ), not an ( s ). The ( w ) matches the (W) for the dominant trait, a widows peak.

Question Widows peak is dominant trait over a straight hairline. 1)If the genotype is (Ww), what phenotype will be expressed? 2)If the genotype is (ww), what phenotype will be expressed? 3)Why is (ss) not a good set of letters for this trait?

Homozygous vs. Heterozygous Homo: _______________ Hetero: ______________ Zygous: ______________

Homozygous vs. Heterozygous Homozygous: ______________________ (WW) and (ww) are both homozygous. –(WW) is homozygous, and _____________ –(ww) is homozygous, and ______________ Heterozygous: __________________________ of genes or trait –Ww is ____________________________, that’s it.

Question Widows peak is dominant over a straight hairline. 1)What is the genotype of a homozygous dominant trait for widows peak? 2)If the genotype is heterozygous for widows peak, which phenotype will be ‘hidden?’ 3)What trait will be expressed if someone is homozygous, recessive?

Twins Identical twins vs. Fraternal twins –Identical twins: share ________________ ________________ ____. –They come from the same __________and ________________.

Twins? Fraternal twins: Not identical genetically. They are like brothers and/or sisters ______________________________________. –By the way, these these two are NOT twins.

Cougar fans: Same age vs. same time (A) (B) #1#2 Can you match the Cougar Fans same age vs. same time?

Question These two Cougar fans are not fraternal twins. 1)Could their DNA be even more closely related than a pair of fraternal twins?