bio2

• Reproduction is the process by which living organisms produce new individuals of the same species
• Reproduction is necessary for the survival and increase in the population of a species
• The DNA (Deoxyribonucleic acid) molecules in the chromosomes in the nucleus is responsible for the transfer of characters from the parents to the off springs
• During reproduction the reproductive cells produce two copies of the DNA which separate into two cells
• The DNA copies will be similar but not identical to each other, so the new individuals have slight variations from their parents
• DNA copying during reproduction is important for maintaining the body designs of different organisms to survive in the existing environment
• Types of Reproduction


  • Asexual reproduction
  • Sexual reproduction
• Asexual reproduction


  Reproduction in which new individuals are produced from a single parent
• Sexual reproduction


  Reproduction in which two individuals are involved to produce a new individual
• Types of Asexual Reproduction

  • Fission
  • Budding
  • Regeneration
  • Fragmentation
  • Spore Formation
  • Vegetative Propagation
• Fission


  Asexual reproduction by which a unicellular organism divides and forms two or more new individuals
• Types of Fission


  • Binary fission
  • Multiple fission
• Binary fission


  An organism divides and forms two individuals
• Multiple fission


  One organism divides into many daughter cells
• Budding


  A bud like projection is formed on the body of the organism, the bud then develops into a new individual and separates from the parent
• Regeneration


  A part of the body if the organism if cut or broken can develop into a new individual
• Fragmentation


  The body of a simple multicellular organism breaks up into smaller pieces on maturation and each fragment develops into new individuals
• Spore Formation


  Structures called sporangia produce tiny cells called spores, when the spores come in contact with a moist surface, it develops into new individuals
• Vegetative Propagation


  New plants are produced from the vegetative parts of the plant like root, stem or leaf
• Plants produced by vegetative propagation produce flowers and fruits earlier than those produced from seeds
• Vegetative propagation helps in the propagation of plants which do not produce seeds
• Vegetative propagation can also be done artificially by cutting, layering, grafting etc.
• Stamen


  The male reproductive part of a flower, it produces pollen grains in the anther which contains the male germ cell
• Pistil


  The female reproductive part of a flower, it produces ovules in the ovary which contain the female germ cell
• Pollination


  The transfer of pollen grains from the anther to the stigma of a flower
• Types of Pollination


  • Self pollination
  • Cross pollination
• Fertilization


  The process where the male germ cell (male gamete) fuses with the female germ cell (female gamete) to form a zygote
• After fertilization the zygote divides several times and forms the embryo which then develops into the seed and the ovary develops into the fruit
• Sexual Reproduction in Animals

  Involves two parents, each contributing a specialized gamete (an egg or sperm) which fuse to form the fertilized egg or zygote
• Types of Fertilization


  • Internal fertilization
  • External fertilization
• The details of the reproductive process vary tremendously from one organism to another
• Metagenesis


  An alternation of asexual and sexual generations
• Parthenogenesis


  A form of reproduction in which an unfertilized egg develops into an adult animal
• Hermaphroditism


  A single organism produces both eggs and sperm
• Parts of the Male Reproductive System

  • Testes
  • Vas deferens
  • Urethra
  • Penis
  • Seminal vesicles
  • Prostate glands

  
• Parts of the Female Reproductive System

  • Ovaries
  • Oviducts
  • Uterus
  • Vagina
• Phases of Human Sexual Response

  • Excitement phase
  • Plateau phase
  • Orgasm phase
  • Resolution phase
• Vasocongestion


  The filling of a tissue with blood caused by increased blood flow through the arteries of that tissue
• Myotonia


  Increased muscle tension of both skeletal and smooth muscles
• Seeds are the reproductive units of the plant, a seed is a plant itself in an embryo form enclosed in a protective outer covering