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Gene Linkage

APBIO-QGWVJS

Gregor Mendel used pea plants as his experimental organisms. He was quite fortunate in that the seven characteristics that he chose to study appear on different chromosomes. They exhibit independent assortment. However, not all traits are inherited in this way.

Which of the following would NOT be seen in a case of independent assortment with two unlinked genes?

A

A cross of two heterozygotes that resulted in 1000 offspring with a 3 dominant :1 recessive ratio for both trait one and trait two.

B

A cross of two dihybrids that resulted in 1000 offspring showing a 9:3:3:1 ratio.

C

A cross of an individual homozygous dominant for both traits with an individual that was recessive for both traits would result in offspring that showed 100% dominant phenotype.

D

An offspring of two heterozygotes produced 100 offspring in which 90 percent of the offspring exhibited one phenotype.