cycles and patterns

• Diplontic

  Usually observed in animals & higher plants
• Haplontic

  Haploid single-celled or multicellular organism
• Haplontic

  Most fungi; some algae
• Haplo-diplontic

  Haploid/diploid multicellular organism
• Haplo-diplontic

  Plants and some algae
• Mendelism

  Pioneered by gregor mendel
• Mendelism

  Only applicable to organisms exhibiting diplontic life cycle
• Law of segregation

  Chromosomes segregate during pollen/sperm and ovule/egg formation
• Law of independent assortment

  The appearance of one has nothing to do with the others
• Independent assortment of chromosome during meiosis I

  • 8 million possible variations
• Crossing over during meiosis

  • Produce recombinant chromosomes which combine genes inherited from our parents
• Chance mutation

  • Adds up to this genetic variation
• Random fertilization

  • 64 trillion diploid combinations in human
• Asexual reproduction

  Conduction of offspring w same genetic material as the parent
• Asexual reproduction processes

  • Either or both from the egg cell (2n) or somatic cell (2n) via several processes
• Agametic reproduction

  No gametes/sex cells involved
• Agametic reproduction processes

  • Fission, budding, fragmentation
• Vegetative reproduction

  From the somatic (body) structure
• Parthenogenesis

  Strictly from the unfertilized egg cell
• Apomixis

  From the unreduced egg cell ("megaspore mother cell") and/or somatic egg cell (nucellus: covering of the ovule)
• Apomixis

  Fruits & seeds formed asexually
• Apomixis

  Mainly in angiosperms (flowering plants) & gymnosperms (cone-bearing plants)
• Apomixis

  Offsprings are genetically identical to the parent plant
• Parthenogenesis

  Development of an embryo from an unfertilized egg
• If favorable conditions

  Parthenogenesis then female offspring (cloned)
• If unfavorable (shortened daylight, low temp, lack of nutrients)

  Sexual repro then it can have a male offspring
• Homeotic genes


  They select the identity of entire segments/structures in the bodies of developing organisms
• Homeobox (hox genes)


  Specific dna within homeobox gene that regulates patterns of development
• Sexual reproduction

  Reproduction of offspring with distinct genetic material with the parent in the process of fusion of opposite gametes (male; n) (female; n)
• Sexual reproduction

  Innate characteristic to pass on the genes to the next generation
• Dioecious

  Male and female organs are found in separate organisms
• Hermaphroditism

  Organisms that can reproduce as both females and males within their lifetime
• 2 types: (1) simultaneous hermaphrodites (i.e. produce both sperm & egg cells in their lifetime) and (2) sequential hermaphrodites (i.e. can invert their sex during their lifetime)
• Protogyny

  Start as juvenile female able to produce egg cells then they become large mature male
• Protandry

  Start as juvenile male able to produce sperm cells then they become large mature females
• Social insects

  Organization & cooperation depends heavily on chemical & tactile communications
• Eusociality

  A reproductive division of labor among members of a population
• Eusociality


  Have a complex social life for the perpetuation of species
• Group selection

  Explains group behavior & altruistic behavior even in human
• Individual selection

  Individual selfishness, competition, unsustainable practices