4. In roses, long stem is dominant over short stems. A Homozygous long-stemmed plant is crossed
with a homozygous short-stemmed plant. What percentage of the resultant rose plants will have long stems?

100%

Explanation:

This question involves a single gene coding for stem length in the rose plant. The allele for long stem (L) is dominant over the allele for short stem (l). This means that allele L will mask the phenotypic expression of allele l in a heterozygous state.

According to the question, a homozygous long-stemmed rose i.e. a rose plant that has same alleles for long stem, LL and a homozygous short-stemmed plant i.e. a rose plant that has same alleles for short stem, ll is crossed. Using a punnet square, all the F1 offsprings of this cross will have a genotype: Ll

Since (L) is dominant over (l), offsprings (Ll) will have a long-stemmed phenotype. Since all offsprings are long-stemmed, this means that 100% of the offsprings are long-stemmed.

answer:

convection currents in the magma drive plate tectonics. heat generated from the radioactive decay of elements deep in the interior of the earth creates magma (molten rock) in the aesthenosphere. the aesthenosphere (70 ~ 250 km) is part of the mantle, the middle sphere of the earth that extends to 2900 km.

4tghyjuklertghyjukl