1)Parakeets have either a yellow or a white pigment base to their feathers; yell
ID: 21864 • Letter: 1
Question
1)Parakeets have either a yellow or a white pigment base to their feathers; yellow is dominant to white. Blackface is a recessive mutation that results in the feather barring that is typically restricted to the head to to be distributed over the face and most of the body.We cross a white-based female to a yellow-based blackface male. The F1 all have yellow feathers with feather barring on just their heads (i.e., yellow base, non-blackface) . We testcross an F1 female with a white feathered blackface male. In our F2, we observe the following:
1546 white birds
1379 yellow blackface birds
227 yellow birds
198 white blackface birds
What is the distance in map units between the genes that code for base feather color and feather barring?
A) 6.8
B) 14.5
C) 87.3
D) 46.2
E) 12.7
2)Are the genes for base feather color and feather barring in parakeets linked?
A)Yes
B)No
3)A cross in corn is carried of with three linked genes in a triply heterozygous genotype for the allele pairs (A, a), (D, d), and (R, r). The dominant allele A results in red leaves, aa plants have green leaves. The dominant allele D results in tall plants; dd plants are dwarfed. The dominant allele R results in ragged leaf margin; rr plants have smooth leaf margins. The triply heterozygote is crossed with homozygous recessives for all three alleels, and the following phenotypes of progeny were observed.
Phenotype # of plants
red, tall ragged 265
red, tall, smooth 24
red, dwarf, ragged 120
red, dwarf, smooth 90
green, tall, ragged 70
green, tall, smooth 140
green, dwarf, ragged 16
green, dwarf, smooth 275
TOTAL 1000
Which gene is in the middle?
A) A
B) D
C) R
4)What is the shortest map distance between adjacent genes in the corn scenario above?
A) 54
B) 20
C) 30
D) 26
E) 16
5)What is the longest map distance between adjacent genes in the corn scenario above?
A) 30
B) 20
C) 16
D) 26
E) 54
Explanation / Answer
1 C 2 B 3 C 4 D 5 C
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