Agricultural Sciences Flashcard Set

1. Basic Genetics

• Key Concepts and Terminology:
  • Heredity: The transmission of genetic characteristics from parents to offspring.
  • Genes and Chromosomes: Genes are units of inheritance located on chromosomes that code for specific traits.
  • Quantitative Characteristics: Traits controlled by multiple gene pairs (polygenic inheritance) displaying continuous variation and influenced by environmental conditions (e.g., milk or egg production).
  • Qualitative Characteristics: Traits controlled by a single pair of genes displaying discontinuous variation with fixed phenotypes, unaffected by the environment (e.g., gender, horn presence, comb type).
  • Alleles: Different forms of a gene.
  • Dominant Allele: Masks the phenotype of a recessive allele (e.g., $T$ for tallness).
  • Recessive Allele: Expressed only when homozygous (e.g., $t$ for shortness).
  • Genotype & Phenotype: Genotype refers to the genetic constitution; phenotype refers to the physical expression.
• Mendel's Laws:
  • Law of Dominance: In a cross between contrasting homozygous traits, the dominant allele masks the recessive allele in the offspring.
  • Law of Segregation: Alleles segregate during meiosis so that each gamete carries only one allele per gene.
  • Law of Independent Assortment: Alleles of different genes segregate independently during gamete formation in dihybrid crosses.
• Patterns of Inheritance:
  • Complete Dominance: Heterozygous individuals exhibit only the dominant phenotypic trait.
  • Co-Dominance: Both alleles in a gene pair are fully expressed in the phenotype (e.g., roan coat color $RW$ in cattle).
  • Incomplete Dominance: Neither allele is completely dominant, producing an intermediate phenotype (e.g., pink flowers from red $RR$ and white $WW$ parents).
  • Polygenic Inheritance: Traits determined by the cumulative additive effect of multiple gene pairs.
• Variation & Mutation:
  • Variation: Differences in characteristics among individuals of the same species.
  • Internal Causes: Meiotic recombination, fertilization, and mutation.
  • External Causes: Climate, topography, nutrition, disease, and light intensity.
  • Mutation: Sudden structural change in DNA (deletion, insertion, substitution, inversion) caused by mutagens such as X-rays, gamma rays, or UV radiation.
• Selection & Breeding Systems:
  • Heritability: Proportion of phenotypic variation attributable to genetic factors. Values above $50\%$ ($0.5$) indicate high genetic transmission potential.
  • Estimated Breeding Value (EBV): Calculated using the formula:
    $EBV = (\text{Weaning Weight} - \text{Average Weaning Weight}) \times \text{Heritability \%}$
  • Related Breeding: Inbreeding and line breeding increase homozygosity but may cause inbreeding depression.
  • Unrelated Breeding: Cross breeding (yields heterosis/hybrid vigor), species crossing (e.g., sterile mules), outcrossing, and upgrading.
  • Genetic Modification (GMO): Incorporates techniques such as Agrobacterium tumefaciens vector insertion, gene gun particle bombardment, micro-injection, electroporation, and lipofection.

2. Agricultural Production Factors

• Land / Soil:
  • Economic Characteristics: Value appreciates over time, supply is fixed/limited, indestructible, immovable, serves as collateral, and is subject to the law of diminishing returns.
• Labour:
  • Types: Permanent, casual, and seasonal; classified by skill level as skilled, semi-skilled, or unskilled.
  • Key Legislation: Basic Conditions of Employment Act (1997), Labour Relations Act, Occupational Health and Safety Act (1993), Compensation for Occupational Injuries and Diseases Act (1993), and Skills Development Act (1998).
• Capital:
  • Types: Fixed capital (land, boreholes, farm buildings), Medium-term/Movable capital (machinery, livestock), and Floating/Working capital (seeds, fertilizer, fuel, operational wages).
  • Financial Management Tools: Inventory, cash analysis book, balance sheet (assets vs. liabilities), income statement (income vs. expenses), cash flow statement, and enterprise budgets.
• Management:
  • Core Functions: Planning, implementation, and control based on strategic vision and mission.
  • Risk Management: Mitigating technical, marketing, financial, legal, and human risks through insurance, enterprise diversification, value adding, specialization, and hedging.

3. Agricultural Marketing

• Marketing Functions: Transport, storage, packaging, processing/value adding, and facilitating functions (standardization and grading).
• Marketing Policy Instruments (4 Ps): Product design, Price determination, Placement/distribution, and Promotion.
• Demand and Supply Dynamics:
  • Law of Demand: Inverse relationship between price and quantity demanded.
  • Law of Supply: Direct relationship between price and quantity supplied.
  • Price Elasticity: Sensitivity of quantity demanded or supplied relative to price changes.
  • Market Equilibrium: Intersection where quantity demanded equals quantity supplied. Government intervention includes floor prices (minimums) and ceiling prices (maximums).
• Marketing Systems & Channels:
  • Free Marketing: Includes farm-gate selling, fresh produce markets, livestock auctions, contract marketing, and internet marketing.
  • Agricultural Cooperatives: Member-owned organizations operating under democratic principles for production, service, marketing, or purchasing advantages.
  • Controlled Marketing: Government-regulated systems designed to maintain price stability.
• Key Legislation: Marketing of Agricultural Products Act (No. 47 of 1996), Perishable Products Export Control Act (No. 9 of 1983), Consumer Protection Act (No. 68 of 2008), and Meat Safety Act (No. 40 of 2000).

4. Agricultural Entrepreneurship and Business Planning

• Phases of Entrepreneurship: Opportunity identification, feasibility evaluation, resource determination, business plan formulation, and operational management.
• Business Plan: Strategic roadmap detailing operational structure, goals, financial projections, and feasibility for securing capital.
• SWOT Analysis: Strategic assessment tool evaluating internal Strengths and Weaknesses alongside external Opportunities and Threats.