Please explain. Thank you . (1) Two true breeding stocks of flowers were crossed
ID: 300675 • Letter: P
Question
Please explain. Thank you .
(1) Two true breeding stocks of flowers were crossed. One parent had round, green seeds and the other had yellow, wrinkled seeds; all F1 individuals had round, green seeds. If 100 F2 offspring resulted from a self-cross of a F1 individual, approximately how many would have round, yellow seeds if the genes controlling seed color and shape are on different chromosomes?
A) 0
B) 6
C) 19
D) 58
E) 90
(2) A gardener crosses two true-breeding strains of plants; one strain has dark blue flowers; the other has white flowers. All the F1 progeny of this cross have light blue flowers. When the F1 progeny are self-crossed, the gardener observes a 1:2:1 ratio of progeny with dark blue, light blue and white flowers, respectively. The most likely explanation of these findings is:
A) Complete dominance
B) Incomplete dominance
C) Environmental effects
D) Polygenic inheritance
E) X-linkage
Explanation / Answer
Answer:
1). C. 19
Explanation:
Based on the information, round is dominant over wrinkled and green is dominant over yellow.
The F2 phenotypic ratio would be as follows.
Round, green = 9/16 *100 = 56
Round, yellow = 3/16 * 100 = 19
wrinkled, green = 3/16 * 100 = 19
Wrinkled, yellow = 1/16 *100 = 6
2). B. Incomplete dominance
Explanation: One gene with three traits is incomplete dominance.
AA = Dark blue
aa = White
Aa = light blue