Botany: Plant Genetics and Physiology

Definition: Study of heredity and variation in plants.
Key Concepts:
- Genes: Basic units of heredity; made up of DNA.
- Chromosomes: Structures that organize and carry genes; typically, plants are diploid (two sets of chromosomes).
- Alleles: Different forms of a gene; can be dominant or recessive.
- Genetic Variation: Arises from mutations, gene flow, and sexual reproduction.
- Genetic Engineering: Techniques like CRISPR used to modify plant genomes for desirable traits (e.g., pest resistance, drought tolerance).
Techniques Used:
- Molecular Markers: Used to identify genetic variation (e.g., SSR, SNP).
- Crossbreeding: Traditional method of combining traits from different plants.
- Tissue Culture: A technique for growing plants from cells or tissues in a controlled environment.

Definition: Study of the functions and processes of plants.
Key Processes:
- Photosynthesis:
  - Occurs in chloroplasts; converts light energy into chemical energy.
  - Main equation: 6CO2 + 6H2O + light energy → C6H12O6 + 6O2.
- Respiration:
  - Process of breaking down glucose to release energy.
  - Occurs in mitochondria; aerobic respiration produces CO2 and H2O.
Water Transport:
- Xylem: Vascular tissue responsible for water and mineral transport from roots to leaves.
- Phloem: Transports sugars and nutrients produced during photosynthesis from leaves to other parts of the plant.
Growth Regulation:
- Hormones: Chemicals like auxins, gibberellins, and cytokinins regulate growth and development.
- Phototropism: Growth response to light, allowing plants to optimize photosynthesis.
Stress Responses:
- Abiotic Stress: Responses to environmental factors such as drought, salinity, and temperature extremes.
- Biotic Stress: Responses to pathogens and herbivores; includes structural and chemical defenses.
Reproductive Physiology:
- Pollination: Transfer of pollen from male anthers to female stigma; can be biotic (insects) or abiotic (wind).
- Seed Development: Involves fertilization and the formation of seeds, which are crucial for plant reproduction and survival.

Study of heredity and variation specifically in plants.
Genes are the fundamental units of heredity, composed of DNA.
Chromosomes organize and transport genes; most plants are diploid, featuring two chromosome sets.
Alleles represent different gene forms; they can be categorized as dominant or recessive.
Genetic variation is introduced through mutations, gene flow, and sexual reproduction.
Genetic engineering employs methods like CRISPR to enhance plant traits, such as pests and drought resistance.
Molecular markers (like SSR and SNP) allow identification of genetic variation.
Crossbreeding blends traits from various plants using traditional methods.
Tissue culture is a technique for growing plants from individual cells or tissues in a controlled setting.

Focuses on understanding functions and processes within plants.
Photosynthesis occurs in chloroplasts, transforming light energy into chemical energy; summarized by the equation: 6CO2 + 6H2O + light energy → C6H12O6 + 6O2.
Respiration, which takes place in mitochondria, involves breaking down glucose to release energy, resulting in the production of CO2 and H2O during aerobic respiration.
Xylem is the vascular tissue that facilitates water and mineral movement from roots to leaves.
Phloem is responsible for transporting sugars and nutrients generated during photosynthesis from leaves to other plant parts.
Growth regulation in plants is influenced by hormones such as auxins, gibberellins, and cytokinins, which guide growth and developmental processes.
Phototropism allows plants to grow toward light, enhancing photosynthesis efficiency.
Plants respond to abiotic stress (e.g., drought, salinity, temperature extremes) as well as biotic stress (e.g., threats from pathogens and herbivores) through defensive mechanisms—structural and chemical.
Pollination involves transferring pollen from male anthers to female stigma, facilitated by biotic (e.g., insects) or abiotic (e.g., wind) agents.
Seed development is crucial for plant reproduction and survival, encompassing fertilization and the formation of seeds.