Evolutionary Quantitative Genetics

Questions: 1. All living organisms require energy to power their metabolic processes. How do autotrophs such as green plants obtain this energy? Describe the process in detail. After the green plants obtain this energy, how do they (and hetertrophs) use the energy to power their metabolic reactions (what process?). Describe this process. 2. What plant growth regulator(s) causes trees to become dormant in the fall? How is this dormancy broken in the spring? Describe what happens (with respect to growth regulators) as a tree becomes active in the spring after spending a dormant winter. 3. What is Mendelian genetics? How does it differ from non Mendelian genetics? How do mutations occur and what is their effect? Answers: 1. Autotrophs obtain their nutrients and energy from the sunlight, through photosynthesis process in most of the cases. However, in some rare cases they use chemical energy that is obtained from oxidation process. This energy is used to synthesize the necessary organic compounds from the inorganic substances (Tran et al., 2013). In autotrophs, the reduction of carbon dioxide to carbohydrates takes place via chemical reactions. Utilizing the energy generated during reaction ATP and NADPH are formed. The energy is stored inside ATP and used in the other metabolic reactions. In the heterotrophs, energy is generated by the oxidation of the reduced organic carbons obtained from plant source to carbon dioxide. This process also releases energy that is utilized in the metabolic reactions of heterotrophs (Tran et al., 2013). 2. Several genetic and chemical growth factors cause dormancy in plants during fall. The chemical factors include the growth hormones of plant such as abscisic acid, cytokinins, auxins, gibberellins etc. Some environmental growth factors are also there such as, level of humidity, availability of water, temperature etc. In the spring, the physiological activities of plant start to function again that had almost stopped during the winter for the adverse environment. The growth regulators start functioning normally with the change in the environmental factors (Roff, 2012). 3. Mendelian genetics deal with the mechanism of the traits and gene transfer from one to the other generation. The Mendelian genetics says that each possible allele for a trait comes from each of the parents but according to the non Mendelian genetics, the traits are related to the single genes of chromosomes. Mutation is a process of permanent alteration of the sequence of DNA of a genome of a particular organism. Mutation causes a permanent change in the phenotypes or genotypes or both. It incorporates new characteristics to the next generation (Roff, 2012). References: Roff, D. (2012).Evolutionary quantitative genetics. Springer Science Business Media. Tran, N. H., Urase, T., Ngo, H. H., Hu, J., Ong, S. L. (2013). Insight into metabolic and cometabolic activities of autotrophic and heterotrophic microorganisms in the biodegradation of emerging trace organic contaminants.Bioresource technology,146, 721-731.