In guinea pigs. dark coat color (C) is dominant over albino (c),and short hair (
ID: 3711 • Letter: I
Question
In guinea pigs. dark coat color (C) is dominant over albino (c),and short hair (S) is dominant over long hair (s). The genes forthese two traits show independent assortment. By evaluating thepossible crosses, determine the most probable genotypes for theparents of each of these seven crosses (ag):
Offspring phenotypes
Parental phenotypes Short Dark Long Dark Short Albino LongAlbino
a) dark short × darkshort 89 31 29 11
b) dark short × darklong 18 19 0 0
Short Dark LongDark Short Albino Long Albino
c) dark short × albinoshort 20 0 21 0
d) albino short × albinoshort 0 0 28 9
e) dark long × darklong 0 32 0 10
f) dark short × darkshort 46 16 0 0
g) dark short × darklong 29 31 9 11
Explanation / Answer
a) The parents produce offspring of about a 9:3:3:1 ratio, meaningthey are both heterozygous. I would show a punnet square of adihybrid cross of two heterozygotes CcSs xCcSs but cramster'sdiagram maker is not working. b) this time the offspring are produced in a 2:2:0:0 making theparents homozygous dominant c)the offspring are produced in a 2:0:2:0 ratio so one parent isCcSS and the other is ccSS. d) this time the offspring are in a 0:0:3:1 ratio making one parentccSs and the other ccSs e) in this one the offspring are in a 0:3:0:1 ratio making oneparent Ccss and the other ccss. f) in this one the ratio is close to a 4.5:1.5:0:0 ratio meaningthe parents might be CCSs and CCss g) the offspring are in a 3:3:1:1 meaning the parents are in a CcSsand ccss again this would be a lot simpler to see if I could draw you thepunnet square unfortunately cramster's drawing tool gives me anerror when I try to insert it in here but I hope my explanationhelps