Answer:
B
Explanation:
Offspring would all have genes of TT, TT, Tt and Tt. All offspring have the dominant tall gene.
Explanation:
The phase of Prophase I of meiosis is very long and divided into 5 subphases: Leptotene, Zygote, Pachytene, Diplotene, and Diakinesis. During a phase of the Diplotene, the degree of condensation is high, which allows individualizing the sister- chromatids that remain attached by the cohesins. The synaptonemal complex disintegrates, and from the centromeres begins a repulsion between homologous chromosomes, which remain associated only with the places where they occur as permutations.
These sites are called chiasmas (Greek, crossed) because they show the crossover of homologous chromatids. Chiasmas represent the cytological finding of the occurrence of permutation. The presence of at least one bivalent chiasm is essential to ensure the correct segregation of the homologous chromosomes in anaphase I.
Oral polio vaccine is highly effective and inexpensive (about US$0.10 per dose, or US$0.30 per child and its availability has bolstered efforts to eradicate polio. A study carried out in an isolated Eskimo village showed that antibodies produced from subclinical wild virus infection persisted for at least 40 years. Because the immune response to oral polio vaccine is very similar to natural polio infection, it is expected that oral polio vaccination provides similar lifelong immunity to the virus.
Contact immunity to polio can occur when attenuated poliovirus derived from the oral polio vaccine is excreted, and infects and indirectly vaccinates unvaccinated individuals.
