(PUC-Campinas 2011) - Question Medium of Biology

Various parts of the human body have specific receptors for some type of tactile stimulus, such as the hands and feet. The tactile receptors present in the hands are called Meissner's corpuscles, while those present in the feet are known as Ruffini's corpuscles. What are the main functions of these corpuscles?

The excreta produced by animals also help maintain environmental health as they serve as a source of nutrients for other living beings present in the animal's environment, thus contributing to the naturally established food chain in that ecosystem. What is the main function of these excreta in this context?

In a genetics experiment, a Biology teacher challenged his 3rd-year high school students to analyze a pea plant that exhibits two characteristics: seed color and seed texture. Seed color can be yellow (AA or Aa) or green (aa), and seed texture can be smooth (TT or Tt) or wrinkled (tt). These characteristics are determined by genes on different chromosomes, so they segregate independently, following Mendel's 2nd Law. The teacher challenges the students to determine the expected phenotypic and genotypic ratios in the F2 (second generation) of a cross between two plants that are heterozygous for both characteristics. Additionally, he asks the students to relate the concept of independent assortment to Mendelian inheritance principles. Based on this information: 1. Calculate the expected phenotypic and genotypic ratios in the F2 of the proposed cross. 2. Explain how the independent segregation of alleles for each characteristic relates to Mendel's 2nd Law and how this principle influences the determination of ratios in the F2.