Which of the following statements would explain a testcross involving F1 dihybrid flies in which more parental-type offspring th
an recombinant-type offspring are produced? a. Recombination did not occur in the cell during meiosis. b. Both of the characters are controlled by more than one gene. c. The two genes are linked but on different chromosomes. d. The two genes are closely linked on the same chromosome.
d. The two genes are closely linked on the same chromosome.
Explanation:
In a testcross involving F1 dihybrid, parent with both the recessive traits is crossed with the F1 dihybrid. Offspring is expected in 1:1:1:1 ratio because formation of gametes is a random process and parental type and recombinant type gametes are expected to be produced in same numbers.
If the two genes are present near to each other on same chromosome they can exhibit linkage. They show tendency to get inherited together. Hence new recombinants are produced in lesser number than the parental type offspring.
Explantion: Silicon is a chemical element that has atomic number 14 and is located in group 14 in the periodic table. Silicon has 23 recognized isotopes, with mass numbers from 22 to 44. The oldest lived radioisotope is Silicon-32, and its half-life has been examined to be around 150 years. Silicon-32 is formed in the atmosphere by cosmic ray spallation of argon and is released on the surface of the earth in precipitation.
