lntro to Genetics 1. Define the following terms : allele - 'r"1-rzi-{s ( gene - ),l..c c-"/, genetics dominant trait - genotype - phenotype - F1 generation - F2 gefieration - ll.-;-.cp r d l u* lti"-l tr-, L, i L] 2. Who was Gregor Mendel? {L..r.., hi*,',- ilrt-t".** fu, l:)o/ L- "u i.l,4-*-'-"'t'b\ Use the following table to complete questions 3, 4 and 5. Stem length Seed shape Seed colour Trait Seed coat colour Pod shape Pod colour Dominant T{ tall I tdund f ybllow lcbloured i inflated i"0feen Recessive f s-hort n wrinkled,lreen white i constricted l yellow 3. Give all the possible alleles which could represent the following: a) tall plant? -? -i- -T t b) short plant? {r c) round seeds? R(. R. d) wrinkled seeds? Yf e) yellow seeds? YY YY f; green seeds? vu g) coloured seed pods? CC,,C. h) white seed pods? c.l i) inflated pods? "TL L, j) constricted pods? i; k) green pods? GC, (=.,. l) yellow pods? (i cr -_.-.--------a-_ J)
r o o*:ih[ht'rtilteilhat wourd resurt from each or the roilowins crosses female, heterozygous X male, heterozygous \ o S.f r( -\ b) trait: seed colour ) female, homozygous dominant X male, homozygous recessive c) trait: pod shape 7 female, homozygous dominant X male, i -1- _*-:--t-j ]-_ L'.zL^lfr.t_t---, l.l, lii heterozygous t B:U:i""ililHJl,:fl1ff".il*l* the senotvpic ratio and phenotypic ratio ')+ff;f' lenstli,qenotvpe ratio pnenotvpe-rarrp Tl-' i,o16"/u -+-*ab ico % b) trait: stem lenqth TTXtt qenotvpe ratio Tt - ti3c)'/. phenotype ratio **w tc,}'1. c) trait: TtX stem length Tt -?i--- I **'7 ll + <ltr genotvpe ratio TT 7;,i TT ++ 5DZ 2;.1, phenotype ratio 'f&q-q*?e "/* "/' -
l. 10. Albinism is a recessive trait in humans.'a'is the normal gene and'a'is the albino gene. a) What chance is there that an albino father and a homozygous normal mother could produce an albino child? CZ.-l,..,- nce b) What chance is there that an albino mother and a heterozygous normal father could produce an albino child? A:o ;A 'l ckc''11*- \- 11. ln humans brown eyes (B) are dominant over blue eyes (b) A brown eyed man marries a blue eyed woman. They have eight children, all are brown eyed. What are the possible genotypes of each person in the family? (Mother, father and kids) " nrc{_fur - b13 B 6b t5b,b_ [bb bb f' *eedl{-= 6r) k*r'c{"'r' 'Bl' 12. The parents of a blue eyed man were both brown eyed. He marries a brown eyed woman whose father was brown eyed and whose mother was blue eyed. They have one child who is blue eyed. What are the genotypes of the individuals mentioned? r,*-.b = -B b \ fv\al-r\ : L' lo 6)$Y9g)-r1- b b -*-------q il,*r;rl' bb r ^ f- [ti' Pi''* {'\-\<'r t \:,l ID a++ b)-w_ pc:,"ri Lr t { I *# b BB *{ Bb bu :, y,tc l-l.r.' [,, b -[.i-l..= 'BL) Vo.LY "?,V: -V nc* VVt, [*-*t*" *.,tc*.^
\ \ 6. ln guinea pigs, a black coat is dominant over a brown coat. What would be the chance for 2 guinea pigs that are heterozygous for this trait to have a brown offspring? Show your work. - 25 ''1, e-l'cn-rrlc( 7. White (W) is dominant over black (w) in sheep. Sir Curlylocks is your prize ram by all ram-judging standards. An individualwishes to purchase the ram from you for 2 million dollars!! The only condition for the sale is that he will never produce any black offspring. How could you prove to this individual that you ram is indeed 'pure'? Show your work. i 'tc.rt i*r L',-c:1,<j * :) c- v c :'> i.*- 't Ur h.rrr*,1 ( (i4,sn'1- rrtrl * *- 'rtu bte"ck t k fl lr:,v-fr 8. You have discovered another plant species! This time, the flowers are either red or white. When you cross a red plant with a white plant, all the flowers of the offspring are red. What do you know about the alleles of this plant? t *fl = r-[.. "r. r vr cu,r.'l.*,[1. l* hj* SC; L: Lea-t 9. ln guinea pigs, black fur is dominant (B) to white fur (b). What are the phenotype and genotype ratios for the offspring of 2 heterozygous parents? 'phe,",-c,\ [( $ {4t5 hb ab bb t:f vt,\ fn l,r\." c k- 1;'1, urll ZS'/- B13 wb b l, "2.;'/.-*r- c t \U /, l; ''1.
L bv) 13. A man and his wife are both heterozygous for brown eyes. They have six children, all of whom have blue eyes. t) b) What are t z)l./ lr ;c{' c bn 6.r' ances that if she has a seventh child it will have brown eyes? c) What are the chances that if she had a seventh child it will have blue eyes? Z5''l a-[cr-r'tc{ 14. Complete the Punnett Squares for each of the crosses and give the phenotype and genotype ratios for each. Legend: B= brown eyes and b= blue eyes S= healthy seed and s= poor seed T= tall and t= short t- A)BbxBB C) TTxtt ul lcc,?, i:'ri,,-r) 615 ' 5L'"(, \(& sc'/"t*,u\ t ----a blr' ->L L''f- v"o ' /, rl 15. a) Huntington's is a fatal autosomal dominant disease. lf a heterozygous man who has Huntington's marries a normal female, what are the chances that their child will have Huntington's? I lg-, L, ';e '/- L-b tto "1, ll('/" '-tal"-..t G,^ llc'' /, 1i 5C c'1 \a 6- ['1 cr-,r"( { b) How would the probability change if Huntington's was a,".*rir" disease? \- I ( ^ci ', / C- tii Ct' t'i-( (
\ SnYy s*$/ 16. What is the difference between a monohybrid cross and a dihybrid cross? I r"(t 17. what is the law of lndependent Assortment?, (-utle((\ 2)".-t', ' -t ').''>(" (l In I.*,,'l..n.c-". o( I +-y...- t r'ic (: '-'tt'..-.(k.i L.u\ho '', t=-rt1 s- orf &-?,.c\ v ou-._t 18. A pea plant is heterozygous for both seed shape and seed color. lt is crossed with a dented homozygous yellow pea. S is the allele for the dominant, spherical shape characteristic; s is the allele for the recessive, dented shape characteristic. Y is the allele for the dominant, yellow color characteristic; y is the allele for the recessive, green color characteristic. What will be the distribution of these two alleles in this plant's gametes? Show your work using a Punnett square..l -Y >I ; 1 5 3 S*Yl S.,)Y S CV J'; I y S"'Yv At;Y V s'/ :' YY S' Y., *'Y v <)1.,j / =., Yy ::Y, *t Y"l - S. =;rl''', I=. tl,-**d Y,,=..1n [[,*, J'u;'rt -Y S=, YY S.n Yy t",y Y nn Yv W W.b"D 19. ln summer squash, white fruit color (W) is dominant over yellow fruit color (w) and disk-shaped fruit (D) is dominant over sphere-shaped fruit (d). lf a squash plant true- breeding for white, disk-shaped fruit is crossed with a plant true-breeding for yellow, sphere-shaped fruit, what will the phenotypes and genotypesf,.* ww,{c{ ' -" 'tr(+f,,^1 *? \Jd WD W-D IOC)'f, \ro [',, fe, + ct,=1 "lrr.,3,i t('dl $J* b.l w"l "r d
L. 20. Albinism 1+ is a receiiive disease and Huntinfion,, s i is a dominant disease.!r'r,r A c. Male: Recessive fir Huntington's"anJ heterozygous for Albinism. Female: Heterozygous for Huntington,s and Albinism " '' "'-ffi 4,. nn what will be ilre oistriilu?on rdr.ruuru, of or these rnese two IWo areres alleles in tn thi$;: this parents, gametes? Give all possible genotypes and phenotypes. / j..r.x -t L Cr1"^l,3?''n. flt.,,rir-j - HA H*!L v x ha ll-.,"',{-,iiir-:s r t*v,." 8r a *nc'*6rc, rr:d). i\c,i,ncl i1 k'\ci"* t c'-lk, IA l'l ri I"1I, AA [J h 4,.,rX Ll, AA \,1",A ; Hfia-rr h!' A,l I r trl lr A t-l t AA' [-] 1., Ar" h[., AA!r a \l{ ti A^'l H t,^,",_,o LhA^ nn (r(.(l.-..-..---...-l hi.aj.-=..-l htr a-?r[ HhAA zr'rb H '1.,A.. Wtu i,, Zl,. l-t ki zr-c; ' t * hh AA v/tv hl,r A c- *ttv 21. complete the Punnett square that would show the Fr generation when 2 heterozygous black, rough-coated guinea pig*i".rossed. (Genes for black and rough are dominant.) 13h" f{; - @lrv.2/te. v./rv?,, llr 2-/ hhcrr\ 'lto ti L; fr?l'{. I3irR" lsb; r 3) How many of the offspring will be black and rough?,1 bj How many of the offsprin! wiil be btack and smjoth?--? gl How many of the offsprin! wiil be white and rough? -l{- d) How many of the offspring wiil be white and smjothr--l--