Science Homework Help

Personal Genetic ProfileAlanna StevensSylvia Tesori03/03/2020 PurposeExamining inherited human characteristics of myself and family to see if they aredominant or recessive phenotypes. The characteristics examined will be straight thumbs or‘hitch-hiker’ thumbs, tongue roller or non-roller, free ear lobe or attached ear lobe, 2 cords or 3cords in flexed wrist, and left thumb on top or right thumb when hands are clasped . Materials- Mirror Procedures1. Tongue rollingTry to roll your tongue into a U shape, with the groove down the middle. Tongue rollingis dominant to non-rolling.2. Straight thumb vs hitch-hiker’s thumbTry to bend your thumb back towards your body (without help from your other hand). Athumb that curves back is called a hitch-hiker’s thumb. The gene for hitch-hiker’s thumbis recessive to the gene for a straight thumb.3. Flexed wristClench your fist and flex your wrist. Can you see two or three cords? Two cords aredominant to three cords.4. Ear lobesExamine your ear lobes. Free ear lobes are dominant to attached ear lobes.5. Clasped handsClasp your hands in front of you. Is your left thumb over your right thumb? Left overright is dominant over left. ObservationsAlanna’s possible genotypesCharacteristicTongue rollingHitch-hiker’s thumbWrist cordsEar lobesHand clasp Dominant/RecessivePhenotypeT/tH/hW/wE/eC/c GenotypeTT or TthhWW or WweeCC or Cc Family’s Results from each procedureCharacteristicTongue rollingHitch-hiker’sthumbWrist cordsEar lobesHand clasp AlannaYesYes BrotherYesYes MomYesYes DadYesStraight thumb 2 cordsAttachedLeft thumb 2 cordsDetachedRight thumb 2 cordsDetachedRight thumb 2 cordsAttachedLeft Thumb AnalysisFirst, I looked at the tongue rolling phenotype, represented by T/t, and observedeveryone in my family, including myself, could roll their tongue. This means we could possibly allhave the homozygous dominant genotype, TT. It could also be possible my parents are eachheterozygous dominant, Tt. If this was the case, if they had 4 children ¼ would be homozygousdominant, TT, 2/4 would be heterozygous dominant, Tt, and ¼ would be homozygous recessive,t, meaning that offspring could not roll their tongue. The ratio would be 1:2:1. There is also thechance one of my parents has the homozygous dominant genotype and the other oneheterozygous dominant, if these genotypes are put into a Punnet square, there is a 1:1 ratio of 2offspring being homozygous dominant, and 2 heterozygous dominant.When viewing my family’s thumbs, represented by H/h, everyone but my father had therecessive phenotype for ‘hitch hiker’s’ thumb, he had the dominant straight thumb. My fathermust have the heterozygous dominant genotype, Hh, and my mother, brother and I have thehomozygous recessive genotype, hh. When looking at a Punnet square, with my father’sheterozygous dominant genotype, Hh, and my mother’s homozygous recessive genotype, hh,there could have been a ¼ chance of an offspring with the heterozygous genotype, the same as my father. Knowing that at least one child with the recessive phenotype, means the father isheterozygous dominant.Observing my family’s flexed wrists, represented by W/w, everyone had 2 cordsshowing. This means we could all be homozygous dominant, WW, or possibly heterozygousdominant, Ww. If my parents were both heterozygous dominant, and are expecting a fourthchild, this child could still have a 75% chance of having 2 cords, and a 25% chance of 3 cords.This is because chance has no memory. In a Punnet square, it is possible 1 offspring could havebeen homozygous recessive, ww, 2 offspring heterozygous dominant, Ww, and one offspringhomozygous dominant. Another possibility being one parent is homozygous dominant, and theother one heterozygous dominant. In a Punnet square this would show a 1:1 ratio of 2 offspringbeing homozygous dominant and the other 2 offspring being heterozygous dominant.Identifying my family’s ear lobes, represented by E/e, my mother and brother havedetached ear lobes, and my father and I have attached ear lobes. This means my mother andbrother must be heterozygous dominant, Ee, and my father and I are homozygous recessive, ee.When my parents reproduced this showed a 1:1 ratio. If they had four children, 2 offspringwould have the heterozygous phenotype, detached earlobes, and the other two would haveattached ear lobes, the homozygous recessive phenotype.Lastly looking at clasped hands, represented by C/c, I got the same results as the earlobes, but switched. My father and I got heterozygous dominant, Cc, and my brother andmother got homozygous recessive, cc. This means my father and I put our left thumbs overtop,and my mother and brother put their right thumbs overtop. If we put these results on a Punnetsquare, 2/4 offspring would be heterozygous dominant, while the other 2/4 offspring would behomozygous recessive, and the ratio would be 1:1.In humans, the chromosomes come in pairs, called homologous pairs, they carry genesfor the same traits in the same order, Alternate forms of a gene for the same trait are calledalleles, always on the same spot on each member of homologous pair. Alleles are representedusing letter, for example T would represent the dominant genotype, while the t would representthe recessive genotype, the hidden one. There can be three types of genotypes for single traits,TT would be homozygous dominant, Tt would be heterozygous dominant and t would behomozygous recessive. Environmental factors can also play a roll in the expression of traits.Polygenic traits seem to be particularly influenced by the environment. The traits we looked atwere not influenced by the environment, because they are inherited and not influenced bytemperature or nutrition. ConclusionAfter looking at all my traits, 3 out of 5 were dominant phenotypes. My father and I have4 out of 5 of the same traits, and my brother and mother have all the same phenotypes. I didnot have any problems with looking at everyone’s phenotypes, and had no sources of error. Resources- Mader, Sylvia. Inquiry into Life. 12th ed. Pgs 471 – 488