GENETICS

• Genetics


  The study of heredity and variation
• Heredity


  The passing of traits from parents to offspring
• Variation


  The differences among individuals
• Gene


  A unit of instructions for heritable traits
• Allele


  An alternative form of a gene at a given point on a chromosome
• Dominant allele


  Masks the expression of its partner on the allelic pair, thus it is the expressed trait
• Recessive allele


  Fully or partially masked by its partner, fully expressed only when paired with another recessive allele
• Character


  A heritable feature
• Trait


  A variant for a character
• Homozygous pair


  Has two identical alleles at a given gene locus
• Heterozygous pair


  Has non-identical alleles at a particular locus on the homologous chromosome
• Phenotype


  The observable trait/s of an individual
• Genotype


  The genetic constitution of an individual
• Purebred


  An organism that possesses homozygous characteristics
• Hybrid


  An organism that possesses characteristics resulting from its heterozygous alleles
• Mendelian Law

  1. Law of Dominance

  2. Law of Segregation

  3. Law of Independent Assortment
• Non-Mendelian Law

  1. Incomplete Dominance

  2. Codominance

  3. Sex-Linked
• Autosomal Inheritance

  • Autosomal dominant - one copy of the faulty gene is enough for the trait to be expressed
  • Autosomal recessive - both copies of the faulty gene is needed for the condition to manifest
• Sex-Linked Inheritance

  • X-linked recessive - mother-to-son transmission
  • X-linked dominant - father-to-daughter transmission
  • Y-linked or Holandric - father-to-son transmission
• Human cell has 23 pairs
• Karyotype

  • 46,XY
• Mendelian Laws

  • Law of Dominance
  • Law of Segregation
  • Law of Independent Assortment
• Law of Dominance


  If two alleles differ, the dominant allele will be fully expressed while the recessive allele will have no noticeable effect
• Law of Segregation


  The two alleles for a specific characteristic segregate during meiosis
• Law of Independent Assortment


  The pair of alleles segregates independently
• Non-Mendelian Laws

  • Incomplete Dominance
  • Codominance
  • Sex-linked
• Incomplete Dominance


  Results when two dominant alleles combine to form a phenotype that is in between those two alleles. The expressed trait is not characteristic of the original alleles
• Codominance


  Results when two dominant alleles combine and both characteristics are expressed and are discernible (ex. ABO blood groups)
• Sex-linked

  Genes for a specific trait are carried by sex chromosomes of organisms
• Animal Tissue Types

  • Epithelial
  • Connective
  • Muscle
  • Nervous
• Epithelial Tissue


  Covers and lines body surfaces and cavities. Epithelial tissues are able to protect and form different body structures
• Epithelial Cell Types

  • Squamous
  • Cuboidal
  • Columnar
• Connective Tissue


  Serves various functions such as protection, storage, support, binding, and synthesis of blood cells
• Connective Tissue Cell Types

  • Connective Tissue Proper
  • Loose and Dense
  • Cartilage
  • Bone
  • Adipose
  • Blood cells
• Muscle Tissue


  Functions for the movement and contraction of various parts of the organisms
• Muscle Tissue Cell Types

  • Skeletal
  • Smooth
  • Cardiac
• Nervous Tissue


  Controls responses of the organism to different stimuli
• Nervous Tissue Cell Type

  • Neurons
• Tissue

  • Dendrite
  • Axon
  • Terminal
  • Node of Ranvier
• Plant Tissue Types

  • Epidermis
  • Ground
  • Vascular