2 Question #1How many different kinds of gametes could the following individuals produce?1. aaBb2. CCDdee3. AABbCcDD4. MmNnOoPpQq5. UUVVWWXXYYZz
3 Question #1 Remember the formula 2n Where n = # of heterozygous 1. aaBb = 22. CCDdee = 23. AABbCcDD = 44. MmNnOoPpQq = 325. UUVVWWXXYYZz = 2
4 Question #2In dogs, wire-haired is due to a dominant gene (W), smooth-haired is due to its recessive allele (w).WW, Ww = wire hairedww = smooth haired
5 Question #2AIf a homozygous wire-haired dog is mated with a smooth-haired dog, what type of offspring could be produced.W Ww
6 Question #2AW Ww Ww Wwfg F1 generationw Ww Ww all heterozygous
7 Question #2BWhat type(s) of offspring could be produced in the F2 generation?Must breed the F1 generation to get the F2.Results of F1 Cross: Ww x Ww
8 Question #2B W w W WW Ww F2 generation w Ww ww genotype: 1:2:1 ratio phenotype: 3:1 ratio
9 Question #2CTwo wire-haired dogs are mated. Among the offspring of their first litter is a smooth-haired pup.If these, two wire-haired dogs mate again, what are the chances that they will produce another smooth-haired pup?What are the chances that the pup will wire-haired pup?
10 Question #2C W w W WW Ww F2 generation w Ww ww - 1/4 or 25% chance for smooth-haired- 3/4 or 75% chance for wire-haired
11 Question #2DA wire-haired male is mated with a smooth-haired female. The mother of the wire-haired male was smooth-haired.What are the phenotypes and genotypes of the pups they could produce?Show the results of crossing: Ww x ww
12 Question #2DW ww Ww wwphenotypes: 1:1 ratiogenotypes: 1:1 ratio
13 Question #3 Rr - pink flowers rr - white flowers In snapdragons, red flower (R) color is incompletely dominant over white flower (r) color.The heterozygous (Rr) plants have pink flowers.RR - red flowersRr - pink flowersrr - white flowers
14 Question #3AIf a red-flowered plant is crossed with a white-flowered plant, what are the genotypes and phenotypes of the plants F1 generation?RR x rr
15 Question #3A R R r Rr Rr F1 generation r Rr Rr phenotypes: 100% pink genotypes: 100% heterozygous
16 Question #3BWhat genotypes and phenotypes will be produced in the F2 generation?Rr x Rr
17 Question #3B R r R RR Rr F2 generation r Rr rr phenotypes: 1:2:1 ratio genotypes: 1:2:1 ratio
18 Question #3CWhat kinds of offspring can be produced if a red-flowered plant is crossed with a pink-flowered plant?RR x Rr
20 Question #3DWhat kind of offspring is/are produced if a pink-flowered plant is crossed with a white-flowered plant?Rr x rr
21 Question #3DR rr Rr rr50%: white flowered50%: pink flowered
22 Question #4In humans, colorblindness (cc) is a recessive sex-linked trait.Remember: XX - femaleXY - male
23 Question #4A Two normal people have a colorblind son. What are the genotypes of the parents?XCX_? x XCYWhat are the genotypes and phenotypes possible among their other children?
24 Question #4A XC Y parents XC XCXC XCY Xc XCXc XcY 50%: female (one normal, one a carrier)50%: male (one normal, one colorblind)
25 Question #4B A couple has a colorblind daughter. What are the possible genotypes and phenotypes of the parents and the daughter?
26 Question #4B Xc Y XC XCXc XCY Xc XcXc XcY parents: XcY and XCXc or XcXcfather colorblindmother carrier or colorblinddaughter: XcXc - colorblind
27 Question #5In humans, the presence of freckles is due to a dominant gene (F) and the non-freckled condition is due to its recessive allele (f).Dimpled cheeks (D) are dominant to non-dimpled cheeks (d).
28 Question #5ATwo persons with freckles and dimpled cheeks have two children: one has freckles but no dimples and one has dimples but no freckles.What are the genotypes of the parents? Parents: F__D__ x F__D__Children: F__dd x ffD__
29 Question #5BWhat are the possible phenotypes and genotypes of the children that they could produce?Cross: FfDd x FfDdThis is a dihybrid cross
33 Question #5CWhat are the chances that they would have a child whom lacks both freckles and dimples?This child will have a genotype of ffddAnswer: 1/16
34 Question #5D Possible gametes: FD Fd fD fd x Fd fd A person with freckles and dimples whose mother lacked both freckles and dimples marries a person with freckles but not dimples whose father did not have freckles or dimples.Cross: FfDd x FfddPossible gametes:FD Fd fD fd x Fd fd
35 Question #5DWhat are the chances that they would have a child whom lacks both freckles and dimples?FD Fd fD fdFd FFDd FFdd FfDd Ffddfd FfDd Ffdd ffDd ffddAnswer: 1/8
36 Question #6Sixteen percent of the human population is known to be able to wiggle their ears.This trait is determined to be a recessive gene.These is a population genetics question.Use the following equation: 1 = p2 + 2pq + q2
37 Question #6AWhat of the population is homozygous dominant for this trait?q2 = 16% or .16: q2 = .16q = .4then use : 1 = p + q1 = p + .41- .4 = pp = .6Now use p2 for answer: .62 = .36 or 36%
38 Question #6B What of the population is heterozygous for this trait? We know that q = .4 and p = .6Now use 2pq for answer: 2(.6)(.4) = .48 or 48%
39 Question #7In dogs, the inheritance of hair color involves a gene B for black hair and gene b for brown hair b.A dominant C is also involved. It must be present for the color to be synthesized.If this gene is not present, a blond condition results.BB, Bb - black hair CC, Cc - colorbb - brown hair cc - blond
40 Question #7A What is the expected ratios of their offspring? A brown haired male, whose father was a blond, is mated with a black haired female, whose mother was brown haired and her father was blond.Male: bbCc (gametes: bC bc)Female: BbCc (gametes: BC Bc bC bc)What is the expected ratios of their offspring?
41 Question #7A Offspring ratios: BC Bc bC bc bC BbCC BbCc bbCC bbCc Black: 3/8Brown: 3/8Blond: 2/8 or 1/4
42 Question #8Henry Anonymous, a film star, was involved in a paternity case. The woman bringing suit had two children, on whose blood type was A and the other whose blood type was B.Her blood type was O, the same as Henry’s!The judge in the case awarded damages to the woman damages to the woman, saying that Henry had to be the father of at least one of the children.
43 Question #8AObviously, the judge should be sentenced to Biology. For Henry to have been the father of both children, his blood type would have had to be what?IA IB Answeri IAi IBii IAi IBi