91. Cell Reproduction Notebook Check 92. Karyotype Lab (graded) 93. Intro to Genetics Reading Guide (stamped) 94. Genetics Notes 95. Punnett Squares 96. More Punnett Square Practice 97. Exceptions to Mendel’s Rules 98. Oompah Loompa’s 99. Progress Report # POP QUIZ! 101. Pedigrees (a & b) 102. Ugly Baby Lab 103. Genetic Disorders

Finish Genetic Disorders #103 3/29 & 3/30 Genetics Unit TEST!

a medical procedure used to diagnose chromosomal disorders in a developing fetus. A small amount of amniotic fluid, which contains fetal tissues, is extracted from the amniotic sac surrounding a developing fetus, and the DNA is examined.

Gregor Mendel = father of heredity – Mid 1800s purebred – Studied garden pea plants (because they could produce purebred individuals) – Studied how traits were passed from one generation to the next

– Mendel came up with several important concepts 1.Parents pass on genes 2.For each trait, an organism has 2 genes (1 allele from Mom and 1 from Dad) 3.Alleles can be dominant and recessive Tall plants could equal TT or Tt, short = tt Genotype Genotype = genetic make-up for trait (TT) Phenotype Phenotype = physical look of trait (tall)

identical If organisms contain two identical alleles for a trait, it shows that trait. Curly hair = HH Straight hair = hh different If organisms contain two different alleles for a trait, it shows the dominant trait. Curly hair = Hh

Used to predict the possible combinations of dominant and recessive alleles in the offspring. Genotypic ratio Genotypic ratio = 1 RR : 2 Rr : 1 rr Phenotypic ratio Phenotypic ratio = 3 pink : 1 yellow

Dad = XY, some sperm have X, some have Y Mom = XX, all eggs have X because that’s all Mom has to donate Who determines gender of baby – Mom or Dad?

The genes for traits found on different chromosomes separate independently when gametes are made.

homozygous recessive A deliberate genetic cross with a homozygous recessive individual that can be used to determine whether an organism is homozygous or heterozygous dominant for a trait.

Phenotype is a mix of genetics and environment

1.Green pea plant (GG) X Green pea plant (Gg) 2.Tall plant (TT) X short plant (tt) 3.Two tall plants (Tt) 4.Two white flowers (white = recessive) 5.Homozygous red flower X white flower 6.Homozygous dominant brown mouse X heterozygous brown mouse (tan = recessive) 7.Heterozygous white rabbit X black rabbit. 8.Two heterozygous white rabbits. (black = rec) 9.How would you figure out if a purple plant (dominant) is heterozygous vs. homozygous? #96 More Punnett Square Practice (make Punnett Squares & describe offspring using genotypic and phenotypic ratios)

GENOTYPIC RATIO PHENOTYPIC RATIO

Sometimes genetics isn’t always as simple as Mendel’s Law of Dominance

BLEND Heterozygote is a BLEND of the 2 homozygotes RR = red flowers rr = white flowers Rr = PINK flowers Cross two pink flowers. Genotypic ratio 1:2:1 Phenotypic ratio 1 red: 2 pink: 1 white

BOTH Heterozygote show BOTH traits BB = black cows WW = white cows BW = black & white BB X WW All BW offspring Genotypic ratio = 0:4:0 Phenotypic ratio = 0:4:0

Traits that have more than two alleles. Blood types –  3 alleles A and B are co-dominant O is recessive to A and B  4 phenotypes 1)Type A  blood contains “A” proteins  genotype: AA or AO

2) Type B  blood contains “B” proteins  (genotype: BB or BO) 3)Type AB  blood contains both proteins  genotype: AB 4) Type O  neither protein present in blood  Genotype: OO AB is an example of ________________.

Several genes are inherited from each parent for 1 trait. Many possible phenotypes. Examples: skin color, eye color, height, weight ABC, ABc, AbC, aBC = dark abc, abC, Abc, aBc = light

ABCABcAbCAbcaBCaBcabCabc ABC ABc AbC Abc aBC aBc abC abc

Located on X chromosome Females are only carriers Mostly males are affected Colorblindness, hemophilia, baldness X B X B = normal female X B X b = carrier female X b X b = colorblind female X B Y = normal male X b Y = colorblind male Cross a carrier female with a normal male. Explain the possible offspring.