SchoolTutoring Submission Error - Please provide a valid contact phone number.
Close

Not a member yet? Register now and get started.

lock and key

Sign in to your account.

Account Login

Forgot your password?

Biology Review of Genetics and Probability

16 Jul Posted by in Biology, Probability | 265 comments

Overview:  Chance and Probability
Geneticists use the principles of chance  and probability to express the results of genetic experiments with pea plants, as well as other plants and animals.  In mathematical terms, probability refers to the fraction (or percentage, in decimals) of times an event can occur.  According to the product rule for independent events. the probability of events occurring together is the product of the probabilities for each event multiplied.  For example, the probability of a girl being born is 50 % , but the probability for two girls being born in the same family is 50% x 50% =25%.  This does not necessarily mean that a specific family will have a girl if another family has a boy at the same time, just that the overall probability, in a sample of many, will be 50%.

Predicting Genetic Crosses
In Mendel’s experiments, seven simple genetic factors were manipulated, such as whether the seed is round or wrinkled, the pod is green or yellow, and so on.  At the time those experiments were formed, the way that alleles separate during meiosis and other details of cellular reproduction were not known.  Geneticists assume that alleles segregate during meiosis in a 1:1 ratio, and that gametes combine randomly.  Suppose the dominant gene for round seeds is called R and the recessive form ( for wrinkled seeds) is called r.  One heterozygous parent with phenotype Rr mated with another heterozygous parent with phenotype Rr will have offspring with the probability (1/2 R +1/2 r)(1/2 R + 1/2r) or 1 RR, 2 Rr, 1rr for genotypes, and 3 with round seeds and 1 with wrinkled seeds.  Geneticists often use thousands of trials to produce as many offspring as they can to use the rules of probability,

Punnett Squares and Testcrosses
The range of probable genetic crosses can be demonstrated by drawing a simple grid with all the alleles contributed by one parent on one side and the other parent on the other, then showing each possibility in each square of the grid.  That way, all the possibilities can be accounted for.  http://schooltutoring.com/wp-content/uploads/sites/2/2013/07/punnett-square-green-peas.jpg

Both parents, in this case, contribute G and g.  In addition, biologists can perform a testcross if they have the phenotype to discover the genotype.  In the example above of the green pods, the genotype could be GG or Gg.  By crossing it with a plant with yellow pods (gg), if the genotype is GG, all the offspring will have genotype Gg and have green pods.  If the genotype is Gg, half the offspring will have genotype Gg, with green pods.  The other half will have genotype gg with yellow pods.

Monohybrids and Dihybrids
Some hybrids have only one trait, involving one pair of alleles, and others involve separate pairs of alleles and two separate traits.  When only one trait is involves, the possibilities are simple, and the Punnett square is a simple 2 X 2 grid.  A relatively simple trait in humans is whether earlobes are free (dominant) or attached (recessive).  If two individuals are heterozygous for the trait, their offspring might have the following genotypes:  EE, Ee, Ee, and ee.  If two separate traits are involved, the Punnett square will be larger because of the many different possibilities.  For watermelons, solid color green (G) is dominant over striped green (g), and short length (S) is dominant over long (s).  If a green , short watermelon (GGSS) is crossed with a striped, long watermelon (ggss), the grid grows to 4 X 4, with 16 different genotypes in the second generation.

Incomplete Dominance
Not all alleles are dominant or recessive, however.  Sometimes, both alleles are expressed.  For example, short tailed cats have one gene for no tail(TN) and one gene for long tail (TL).  If two short tailed cats are crossed, the Punnett square has a simple 2 X 2 grid, and the offspring probabilities include 25% long tail (TLTL), 50% short tail (TNTL), and 25% no tail (TNTN).  The roan (reddish-brown) color of some cattle also results from incomplete dominance, as well as many other features of plants and animals.

Interested in Science tutoring services? Learn more about how we are assisting thousands of students each academic year.

SchoolTutoring Academy is the premier educational services company for K-12 and college students. We offer tutoring programs for students in K-12, AP classes, and college. To learn more about how we help parents and students in Grand Rapids, MI visit: Tutoring in Grand Rapids, MI

  1. hefalimp cardijon07-26-14
  2. dryer cleaning houston07-31-14
  3. generique cialis 10mg08-02-14
  4. my husband premature ejaculation08-04-14
  5. online slots08-05-14
  6. web site,08-06-14
  7. cialis best price08-06-14
  8. divorce lawyer08-06-14
  9. achat cialis gГ©nГ©rique08-07-14
  10. Check These Guys Out08-07-14
  11. macarons waar te koop08-09-14
  12. cialis in farmacia08-12-14
  13. no credit check payday loans08-13-14
  14. cialis forum08-13-14
  15. cialis francais08-15-14
  16. My Homepage08-16-14
  17. penis enlargement pills08-16-14
  18. cialis 20 mg effetti08-17-14
  19. mmpr licensed producers mmpr licensed producers08-17-14
  20. buy youtube likes08-17-14
  21. Vaper08-18-14
  22. xlovecam online08-18-14
  23. Begum Law Firm08-19-14
  24. cialis produttore08-20-14
  25. cialis meccanismo d azione08-24-14
  26. metatron08-26-14
  27. Drywall Finishing08-26-14
  28. Popcorn Ceiling Removal08-26-14
  29. Process Servers08-26-14
  30. Wedding hair style for the bride08-27-14
  31. cool android apps yahoo answers08-27-14
  32. vehicle locksmith08-27-14
  33. hostgator türkiye08-27-14
  34. emcee08-27-14
  35. Restore My Vision Today08-27-14
  36. media08-27-14
  37. werbung08-27-14
  38. shakeology cost08-27-14
  39. car auction online08-27-14
  40. frameless door houston08-27-14
  41. rosary beads kopen08-27-14
  42. ganesh chaturthi 201408-28-14
  43. irvine auto repair08-28-14
  44. mazda dealer illinois08-28-14
  45. Casino games08-28-14
  46. how do i know if i have premature ejaculation08-28-14
  47. hyundai sale08-28-14
  48. Jasa Follower Instagram08-28-14
  49. Jasa Menambah Follower08-28-14
  50. One little mortgage website that could save you hundreds!08-28-14
  51. www.youtu.be/1GYUgMrfjXA.08-28-14
  52. Afford a Home with these tips...08-28-14
  53. vw golf tdi08-29-14
  54. Medical tourism08-29-14
  55. buy scentsy online08-29-14
  56. lasik surgery08-29-14
  57. doctors tucson az08-29-14
  58. Illinois Process Server08-29-14
  59. One little mortgage website that could save you hundreds!08-29-14
  60. m8808-29-14
  61. aaron kocourek08-29-14
  62. download app08-29-14
  63. juicy couture uk08-30-14
  64. Houston TX For Sale By Owner08-30-14
  65. Legacy Food Storage08-30-14
  66. address book page template08-30-14
  67. Free android games08-30-14
  68. pore mask08-30-14
  69. Betboo08-30-14
  70. needlework08-30-14
  71. real estate08-30-14
  72. hypnosis08-31-14
  73. young adult fantasy08-31-14
  74. Squirrel Removal Katy08-31-14
  75. navy seals in training08-31-14
  76. home crossfit equipment08-31-14
  77. MovieStarPlanet Cheats08-31-14
  78. bets1008-31-14
  79. cialis al miglior prezzo08-31-14
  80. Learn How To Make Cash With Instagram08-31-14
  81. jam tangan casio08-31-14
  82. Pikkukoala Lastentarvikkeiden erikoisliike08-31-14
  83. promovare siteuri08-31-14
  84. eset nod32 trial key08-31-14
  85. making money on twitter08-31-14
  86. Offer Wall08-31-14
  87. Buy IG Followers08-31-14
  88. Network Support09-01-14
  89. bee wild pest control09-01-14
  90. pest control houston review09-01-14
  91. juicy couture uk09-01-14
  92. sausage patties09-01-14
  93. garcinia cambogia free trial review09-01-14
  94. check out this really cool web page09-01-14
  95. MovieStarPlanet Cheats09-01-14
  96. view it now09-01-14
  97. Fiber Glass Mat/Tissue/Felt09-01-14
  98. Cialis09-02-14
  99. squeeze method for premature ejaculation09-02-14
  100. Guitar Licks You’ll Love - “Stand By Me” on Guitar09-02-14
  101. email leads09-02-14
  102. scuba internships09-02-14
  103. Games and softwares free download09-02-14
  104. House eviction09-02-14
  105. modere rewards09-02-14
  106. home health aid09-02-14
  107. projector bulbs austin tx09-02-14
  108. student aid09-03-14
  109. slots machines games free09-03-14
  110. free bonus slots09-03-14
  111. sabotaging relationships09-03-14
  112. #Counterparty unveils Multi-Signature Support09-03-14
  113. money09-03-14
  114. Denver DUI Lawyer09-03-14
  115. sigue leyendo09-03-14
  116. emotional intelligence training09-03-14
  117. study guide cardiac arrhythmias09-03-14
  118. Online Jobs as Venture Capital09-03-14
  119. Nettbutikker09-04-14
  120. adderall online09-04-14
  121. buy tramadol09-04-14
  122. buy tramadol online09-04-14
  123. buy adipex online09-04-14
  124. cash for gold09-04-14
  125. destination voyage de noce09-04-14
  126. Whatsapp Hackl Spy Conversation09-04-14
  127. NHL09-04-14
  128. click for more info09-04-14
  129. website design in perth09-04-14
  130. caramoan tour package09-04-14
  131. plum lipstick09-05-14
  132. ??? ???? ???? ???? 1 ??????09-05-14
  133. Pest Control Houston Texas09-05-14
  134. perth web design companies09-05-14
  135. how to register MOL account09-05-14
  136. cold stone franchise cost09-05-14
  137. Exterminator Service Houston Texas09-05-14
  138. xlovecam free tokens09-05-14
  139. FanDuel Promo Code09-05-14
  140. epub gratis09-05-14
  141. cheapest insurance quotes09-06-14
  142. emotional intelligence training09-06-14
  143. gap visa credit card09-06-14
  144. compare auto insurance quote09-06-14
  145. vape09-06-14
  146. achat cialis bon prix09-06-14
  147. grooms speech09-06-14
  148. cardiff rent flat09-06-14
  149. low cost insurance quotes09-07-14
  150. orange county bail bonds09-07-14
  151. wine merchants09-07-14
  152. auto insurance quotes in texas09-07-14
  153. Plus Size Lingerie09-07-14
  154. north richland hills real estate09-07-14
  155. leather leggings09-07-14
  156. macchina fotografica reflex prezzo09-07-14
  157. Colusa DUI Defense Attorney09-07-14
  158. Sinisterly - iCloud Hacked, Nudes Leaked09-07-14
  159. cialis09-07-14
  160. Sports wagering09-08-14
  161. commander cialis generic09-08-14
  162. articles09-08-14
  163. Get 10% OFF all "Ad Packs" through October 31st09-08-14
  164. comment gagner de l'argent09-08-14
  165. Luxurious wallet09-08-14
  166. hearthstone arena guide09-08-14
  167. Weight loss for women09-08-14
  168. maryland divorce lawyers09-08-14
  169. free music download sites09-09-14
  170. Ferguson09-09-14
  171. Elephant Art09-09-14
  172. kundalini chakras09-09-14
  173. CHEAP MEDS09-09-14
  174. 1009-09-14
  175. 5c circle cases09-10-14
  176. about.me09-10-14
  177. forex09-10-14
  178. web agency perth09-10-14
  179. meditation streaming09-10-14
  180. banana blue09-10-14
  181. strona firmy09-10-14
  182. xylitol stevia09-11-14
  183. http://www.Ath-m50.net/09-11-14
  184. loyal 9 marketing09-11-14
  185. App Marketing09-11-14
  186. weight loss spa09-11-14
  187. Tea party09-11-14
  188. arkitekter09-11-14
  189. wilnel verdu09-11-14
  190. Bryce09-11-14
  191. Currency Trading09-11-14
  192. cheap soundcloud plays and downloads09-11-14
  193. tas pesta murah09-11-14
  194. saint seiya09-11-14
  195. Trail-Gear Canada09-11-14
  196. facebook kampányok tervezése09-12-14
  197. get soundcloud plays package09-12-14
  198. lose weight fast09-12-14
  199. Get Disability Benefits09-12-14
  200. Wellness Dog Food Coupon09-12-14
  201. free advertising09-12-14
  202. Gambling09-12-14
  203. Learn Hacking Online09-12-14
  204. marriage annulment09-12-14
  205. cupones de descuento09-12-14
  206. beginner guide09-12-14
  207. learn more09-13-14
  208. Hacking Tutorials09-13-14
  209. Chromebase09-13-14
  210. essential oils for children09-13-14
  211. Gadgets for Men09-13-14
  212. elevator hoist cable09-13-14
  213. certyfikat kwalifikowany zus09-13-14
  214. suplementy sklep09-13-14
  215. snippets09-13-14
  216. activation keys09-13-14
  217. boost my likes09-13-14
  218. sobre Ivan Bedia Garcia09-13-14
  219. check my blog09-13-14
  220. Read More09-14-14
  221. orange beach beach Rentals09-14-14
  222. fort collins epoxy floor09-14-14
  223. pages blanches09-14-14
  224. free gadgets09-14-14
  225. arkitekter09-14-14
  226. seo uzmanı09-14-14
  227. putting09-14-14
  228. garden shed plans09-14-14
  229. Email Marketing09-14-14
  230. stopthestresstoday.com/about-me09-14-14
  231. samaa news live09-14-14
  232. Green Smoke electronic cigarettes09-14-14
  233. best lotion for razor bumps09-14-14
  234. www.Facebook.com Livejasmin Hack09-15-14
  235. our website09-15-14
  236. income09-15-14
  237. gate way account09-15-14
  238. bolatangkas09-15-14
  239. cosmetica natural online09-15-14
  240. creamed coconut09-15-14
  241. riflessi diamante 103709-15-14
  242. Decoration Ideas09-15-14
  243. EXPERIENCED AUTO TRANSPORT DRIVERS WANTED09-15-14
  244. tampa movers09-16-14
  245. polecam09-16-14
  246. filtros de agua09-16-14
  247. forever living diet09-16-14
  248. binary options demo account09-16-14
  249. #360MEA09-16-14
  250. Office Cleaning Sydney09-16-14
  251. michelle rodriguez boyfriend09-16-14
  252. online real estate09-16-14
  253. mens fashion blog09-17-14
  254. event atms09-17-14
  255. Zebra Printer Repair09-17-14
  256. videos09-17-14
  257. atms for event09-17-14
  258. guttering London09-17-14
  259. mobile atm09-17-14
  260. Aprender alemán en linea09-17-14
  261. alaska fishing09-17-14
  262. hard money florida09-17-14
  263. ganool09-17-14
  264. baby gender mentor09-17-14
  265. alaska fishing trips09-18-14