In: Biology
1)A homozygous tomato plant with red fruit and yellow flowers
was crossed with a homozygous tomato plant with golden fruit and
white flowers. The F1 all had red fruit and yellow
flowers. The F1 were testcrossed by crossing them to
homozygous recessive individuals, and the following offspring were
obtained:
Red fruit and yellow flowers41
Red fruit and white flowers7
Golden fruit and yellow flowers8
Golden fruit and white flowers44
How many map units separate these genes?
A)17.6
B)17.1
C)15
D)18.1
2)Which of the following, if damaged, would most directly hinder RNA polymerase from attaching to the beginning of a gene?
A)introns
B)exons
C)UTR's (untranslated regions)
D)snRNA
E)promoter region
1) Red fruit is dominant to golden fruit and yellow flowers are dominant to white flowers, let the alleles be R- red fruit, r- golden fruit
Y- yellow flower, y- white flower
plant with yellow flowers and red fruit * plant with golden fruit and white flowers
RRYY * rryy
RY/ry
F1 is test crossed, that is crossed to rryy
RrYy * rryy
RY | Ry | rY | ry | |
ry | RrYy ( red fruit, yellow flowers) | Rryy ( red fruit, white flowers) | rrYy(golden fruit, yellow flowers) | rryy(golden fruit, and white flowers) |
in the RrYy, R and Y alleles are on one chromosome and r and y alleles are on another chromosome, so RY and ry are parental type gametes and Ry and rY are recombinant type gametes, recombinant type progenies are formed from recombinant gametes.
here recombinant progenies are
red fruit, white flowers and golden fruit, yellow flowers
recombination frequency=( number of recombinant progenies/total number of progenies)100
= (( number of red fruit, white flowers + number of golden fruit, yellow flowers)/total number of progenies)100
= ((7+8)/100)100
= 15%
recombination frequency in percentage is the distance between genes in cM.
c) 15
2) promoters are the regions in the DNA where RNA polymerase binds if the promoter is mutated RNA polymerase cannot bind to the DNA and transcribe to RNA.
introns are found in pre-mRNA it is spliced out and exons in between are joined together, 5`UTR is the region at the 5` end of the mRNA which is not translated.
E) promoter region.