Heredity-2

• Variation


  It is the result determined by the factors like environment and heredity
• Condition that develops clear and definite differences among organism

  Also called variation
• Character of Pea Plant

  • Colour of flower
  • Position of flower
  • Height of plant
  • Shape of seed
  • Colour of Seed
• Why did Mendel select a pea plant for his experiment?
• Reasons why Mendel selected pea plant

  • Pea-plant is naturally self-pollinationg
  • A large number progeny (offspring) is obtained
  • The life cycle of a pea plant is of short duration
  • They are convenient to handle
• Gene


  The basic physical and functional unit of heredity
• Important terminologies of genetics

  • Unit Character
  • Monohybrid and Dihydrib cross
  • Traits and Character
  • Dominant and recessive traits
  • Phenotype and genotype
  • Hybrid
• Unit Character


  The definite external character of an individual of a cross
• Monohybrid cross


  When only one unit character is involved in a cross
• Dihydrib cross


  When two unit characters is involved in a cross
• Traits


  The quality of organisms
• Character


  The quality of organisms
• Dominant traits


  Traits which express themselves by covering other traits
• Recessive traits


  Traits which are present but cannot express themselves due to the presence of dominant traits
• Phenotype


  The morphological appearance of an organism
• Genotype


  The genetic make-up of an organism
• Hybrid


  Organisms who have their phenotype and genotype different
• Genetic Technology Engineering


  Technology by which an organism's genetic material is altered or selected so that the organism will have specific characteristics
• Role of DNA test in different researches

  • Forensics
  • Paternity tests
  • Ancestry Tracking
  • Medical Tests
• Selective Breeding


  A process used by humans to develop new organisms with desirable characteristics
• Disadvantages of selective breeding

  • It increases the population of animals
  • It increases the possibility of infectional disease
• Crossbreeding


  The process or the act of producing offspring particularly through mating two purebreed individuals which comes from different species
• Purpose of crossbreeding


  • To take advantage of heterosis
  • To use average breed effects
  • To design a cow herd
  • To target markets
• Heterosis


  The difference in the value of a trait compared to the average value of the parents for the trait
• Artificial Insemination (AI)


  The process of collecting sperm cells from a male animal (sire) and manually depositing them into the reproductive tract of a female (dam)
• Disadvantages of AI


  • It needs well trained technicians and Special devices
  • It requires a long time for the preparation of AI compared with natural fertilization
  • It may cause infection of the body
• In-vitro fertilization (IVF)


  A process of fertilization where an egg is combined with the sperm in-vitro (in glass)
• Advantages of IVF


  • IVF makes it possible for the A couple, who are unable to bear a baby, to have a baby
  • It helps to eradicate genetic and chromosomal disorders
  • It increases the possibility of the birth of a healthy baby
• Disadvantages of IVF


  • There is no guarantee of success
  • Sometimes, it shows the problem of multi-fertilization
  • It is very expensive