2. Ch.9

3.  How are purebreeds different from mixed breeds?  Purebreeds are from parents who share the same genes while mixed breeds are not

4.  Gregor Mendel is known as the father of modern genetics

5.  What process is illustrated on the right?  The purple flower is being fertilized by the pollen of the white flower (cross- fertilization).  What do we call the parental generation?  The P generation  What do we call the offspring?  F1

6.  Mendel looked at several traits. Which is dominant yellow pea seed or green pea seed?  Yellow

7. When you make a cross for one trait like flower color it is called a _______ cross Monohybrid - mono for one hybrid for different

8.  Why are all the F1 purple?  Because purple is dominant to white each F1 flower has a P allele and a p allele.  Why is the F2 different from the F1?  Because in the F2 generation two pp can occur in the offspring

9. Purple flower crossed to White Flower Possible Gametes Purple P Flower P White p Pp Purple heterozygote Pp Purple heterozygote Flower p Pp Purple heterozygote Pp Purple heterozygote

10. F1 crossed to F1 GametesPurple P Heterozygote p Purple P PP Purple homozygote Pp Purple heterozygote Heterozygote p Pp Purple heterozygote pp White homozgote

11.  What does loci mean?  Location of a gene  Define homozygous and heterozygous  Homozygous - same alleles PP or pp  Heterozygous - different alleles Pp

12.  When two traits are crossed it is called a _________ cross  Dihybrid  Why doesn’t a dihybrid cross produce the same outcome as a monohybrid cross?  Independent assortment- where the alleles for pea shape go, have nothing to do with the alleles for pea color.

13.  What is the ratio of phenotypes, coat color and vision?  9 both dominant  3 One dominant, one recessive  3 One recessive, one dominant  1 both recessive

14. Gametes BNBnbNbn BNBBNNBBNnBbNn BnBBNnBBnnBbNnBbnn bNBbNNBbNnbbNNbbNn bnBbNnBbnnbbNnbbnn

15.  What do you think is the purpose of a testcross?  To determine the genotype of a dominant individual  Why cross the unknown individual to a homozygous recessive?  If any recessives show up in the offspring we know the unknown carries the recessive trait.

16.  What is the chance of getting two Bb in a row?  2/4 x 2/4 = 4/16 = 1/4

17.  Does dominant mean more common?  No freckles are not necessarily more common.

18.  What is this diagram called?  Pedigree chart  Why can’t we predict Abigail Lambert’s genotype?  We don’t know about her offspring and she possesses the dominant trait so she could be Dd or DD

19.  Why do you think we call Dd a carrier?  They carry the trait, but since it is recessive you can’t see it.  What type of disorder is this?  A recessive disorder like Cystic Fibrosis

20.  Achondroplasia, a type of dwarfism, is a __________ trait.  Dominant  Huntington’s is also dominant but doesn’t usually take effect until after the age of 30. What is the potential problem with that?  They have already had children and passed it on.

22.  What are two ways to test for inherited disorders in a fetus?  Amniocentesis and Chronic villus sampling.

23.  When red and white make pink offspring it is called _______ dominance?  Incomplete  What is the ratio of the F2 generation?  1red:2pink:1white

24.  In blood type A is dominant to O and B is dominant to O but A and B arre equally dominant. What do we call this type of inheritance?  Codominance

25.  If Maria is type O and her sister is type AB blood and they know there mother’s grandparents are type A. What are the genotypes of their parents?  Mother is I a i and dad is I B i

26. Normal red blood cells and sickle cells

27.  This picture illustrates pleiotropy, what do you think that means?  One gene can have an affect on many different things in the body - sickle cell shaped cells can cause heart failure, kidney failure etc.

28.  How many different genes are involved in skin color? 33  When many genes cause a trait like skin color it is called _______  Polygenic inheritance

29.  What does this picture illustrate?  Independent assortment - shape and color line up separately.

30.  When two genes are on the same chromosome like purple flower and long pollen or red hair and freckles, it is called _________.  Linked - they tend to travel together because the are close together and are rarely separated by crossing over.

31.  What would you expect to be the outcome of the cross GgLl and ggll  1GgLl:1Ggll:1ggLl:1ggll = equal numbers of each type.  Is that what was observed?  No - most were like either parent  What is the chance that crossing over will happen?  17%

32.  The crossing over frequency can be used to calculate the distance between genes on the chromosome. What is the distance between body color and wing shape in fruit flies?  17

34.  Many organisms have chromosomes that determine sex, humans have ___ and ____  X and Y  In chickens it is ___ and ____  Z and W

35.  Where is the eye color gene located? XX  What is the only way to get a female that has white eyes?  The dad must have an X with white eyes

36.  When a gene is on the sex chromosome it is called sex linked. Red/green colorblindness is sex linked.  How would this test for colorblindeness?  A colorblind person would not see the seven in the middle

38.  Queen Victoria passed on a sex linked trait to her family, what was it?  Hemophilia  Duchenne muscular dysytrophy is also sex linked