Question

In a pine’s life cycle, hybrid “1” pine tree the needles were found to have the
alleles Ll (heterozygous) producing long needles. In a hybrid “2” pine tree, the
needles were found to have the alleles ll (homozygous recessive) producing
short needles. If a pollen from hybrid “1” pollinated hybrid “2” to form a hybrid “3”
plant which about 50% were long needle and 50% were short needle. Give the
genotypes for the following structures found in the life cycles of these plants:
Genotype of the pollen grain’s nucleus of plant hybrid “1”?
Genotype of archegonia of plant hybrid “2”?
Genotype of megaspore mother cell of plant hybrid “2”?
Genotype of sporophyte of plant hybrid “3”?
Genotype of microspores of plant hybrid “1”?
Genotype of hypocotyl of plant hybrid “3”?
Genotype of seed coat of plant hybrid “2”?
Genotype of ovary of plant hybrid “2”?

Draw and label the parts of the entire ovule and its content’s at maturity (before
fertilization) of the two Divisions “angiosperm” and “gymnosperm (pine)”. Explain
what happens to the various parts of each ovule. Give differences between
these two ovules.

Answer 1

Genotype of hybrid 1 => Ll

Genotype of hybrid 2 => ll

Genotype of hybrid 3 => Ll, ll

Genotype of  the pollen grain’s nucleus of plant hybrid “1”:

The pollen grain’s nucleus is haploid. So it will have either "L" allele or "l" allele.

Genotype of archegonia of plant hybrid “2”:

Archegonia of plant is also haploid. So it will have only one "l" allele.

Genotype of megaspore mother cell of plant hybrid “2”:

Megaspore is also haploid. So it will have only one "l" allele.

Genotype of sporophyte of plant hybrid “3”:

Sporophyte is diploid. So it will have either "Ll" genotype or "ll" genotype.

Genotype of microspores of plant hybrid “1”:

Microspore is haploid. So it will have either "L" allele or "l" allele.

Genotype of hypocotyl of plant hybrid “3”:

Hypocotyl is diploid. So it will have either "Ll" genotype or "ll" genotype.

Genotype of seed coat of plant hybrid “2”:

Seed coat is diploid. So it will have "ll" genotype.

Genotype of ovary of plant hybrid “2”:

Ovary is diploid. So it will have "ll" genotype.