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Mendelian Genetics

Terminology of Mendelian Genetics Gene: Gene is a segment of DNA that determines a biological character of an organism. It is also called the basic unit of heredity. Genome: The total genetic content of an organism is called genome. Allele or allelomorph: Allele or allelomorph is an alternate form of the same gene in which one is paternal and the other is maternal. For illustration, a gene for the plant height has two alleles - a gene for tallness (T) and a gene for dwarfness (t).  Locus: The point on a chromosome where an allele is located is called locus (pl. loci). Homozygous: A diploid individual that carries two identical (similar) alleles of the same gene is known as homozygous individual or homozygote. For illustration, A pea plant having both the alleles of tallness (TT) is homozygous individual for tallness. Heterozygous: A diploid individual that has two different alleles of the same gene is called heterozygous individual or heterozygote. For example, an individual pea pl...
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Genetic Materials and Genetic Code

Figure 1 Graphic representation of central dogma of molecular biology Image: "Central Dogma of Molecular Biochemistry with Enzymes" by D3r1 via Wikimedia Commons, used under CC BY-SA 3.0. Figure 2 Reverse transcription or Reverse central dogma of molecular biology Image: "Extended Central Dogma with Enzymes" by D3r1 via Wikimedia Commons, used under CC BY-SA 3.0. Figure 3 Structure of nucleotide Image source: "Figure 3.22: DNA Nucleotides" by OpenStax is licensed under CC BY 4.0. Access for free at openstax.org. Figure 4 Structure of pentose sugars in nucleotide Image source: OpenStax College, CC BY 3.0 <https://creativecommons.org/licenses/by/3.0>, via Wikimedia Commons Figure 5 Nitrogen bases in nucleic acids Source: https://2012books.lardbucket.org/books/introduction-to-chemistry-general-organic-and-biological Watson and Crick showing the three dimensional model of DNA prepared using metal scraps FIO054: Figure 5.8c” by Rosenfeld M...
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Plant Growth and Movement

Growth is defined as the permanent increase in size of an organ or its parts in organisms like plants. Growth involves the energy requiring metabolic processes. Growth is followed by development. The development is about all the changes that occur in the life cycle of a plant from germination of the seed to senescence . The development in plants is controlled by different factors categorized as extrinsic and intrinsic factors . The extrinsic factors include light, temperature, water, oxygen, and nutrition, etc. The intrinsic factors are both the intracellular (genetic) or intercellular factors (chemicals such as plant growth regulators). Concept on seed germination Seed germination is the fundamental process by which different plants grow from a single seed into a complete plant. It brings about the sprouting of a seedling from a seed of angiosperms and gymnosperms. Process of seed germination The seed germination happens by four steps - imbibition, activation of enzymes, growth, a...
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