Question: A plant species X with n=5 chromosomes was crossed with a related species Y with n = 7 chromosome…

A plant species X with n=5 chromosomes was crossed with a
related species Y with n = 7 chromosomes. The F1 hybrids produced
only a few pollen grains, which were used to fertilize the ovules
of related species Z with n=7 chromosomes. A few plants were
produced from this cross, and all had 19 chromosomes. The F1
hybrids (with 19 chromosomes) were mated with related species W
with n=11 chromosomes. A few plants were produced from the cross
and all had 30 chromosomes. Following self-fertilization of the F1
hybrids a few F2 plants were produced, each with 60 chromosomes.
These plants were phenotypically different from either of the
original species and were highly fertile. (Refer to chapter 8 in
your text).

a. Explain by diagram and description the events that produced
these fertile F2 hybrids. You must be specific and very clear about
what is happening.

b. Give the karyotype of the gametes produced by the highly
fertile F2 plants.

c. Using appropriate genetic terminology, tell what type of
polyploid plant ultimately arises as a result of the above
crosses.