BIO

• Objectives


  • Differentiate the two modes of plant and animal reproduction (asexual and sexual)
  • List down the parts of the reproductive organs of plants and animals
  • Recognize the advantages and disadvantages of asexual and sexual reproduction in plants and animals
• Compare and contrast the following processes in plants and animals: reproduction, development, nutrition, gas exchange, transport/circulation, regulation of body fluids, chemical and nervous control, immune systems, and sensory and motor mechanisms
• Animal reproduction


  1. Fragmentation

  2. Hermaphroditic

  3. Sterile

  4. Gamete; zygote

  5. Sexual and asexual generations

  6. Develops into a new individual
• Asexual reproduction


  Creation of new individuals whose genes all come from one parent without the fusion of egg and sperm
• Sexual reproduction


  Creation of offspring by the fusion of haploid gametes to form a zygote (fertilized egg), which is diploid
• Female gamete (egg/ovum)


  Relatively large, non-motile cell
• Male gamete (sperm)


  Smaller, motile cell
• Advantages of sexual reproduction

  • Increases genetic variability among offspring
  • May enhance reproductive success of parents when environmental factors change rapidly
• Advantages of asexual reproduction

  • Enables animals living in isolation to produce offspring without locating mates
  • Can create numerous offspring in a short amount of time, ideal for colonizing a habitat rapidly
  • Perpetuates successful genotypes precisely in stable, favorable environments
• Types of asexual reproduction

  • Fission
  • Budding
  • Fragmentation
  • Regeneration
• Fission


  Separation of a parent into two or more individuals of approximately equal size
• Budding


  New individuals arise from outgrowths of existing ones; the offspring may either detach or remain attached
• Fragmentation


  Breaking of the body into several pieces, some or all of which develop into complete adults
• Regeneration


  Regrowth of lost body parts; usually accompanied with fragmentation
• Types of fertilization


  • Internal
  • External
• Internal fertilization


  Male delivers sperm cells directly into the body of the female; her moist tissues provide the watery medium required for sperm movement
• External fertilization


  Mating partners release eggs and sperm into the water simultaneously
• Male reproductive organs


  • Testis
  • Sperm duct
  • Penis

  
• Female reproductive organs


  • Ovary
  • Oviduct
  • Vagina

  
• Metagenesis


  Alternation of asexual and sexual generations
• Parthenogenesis


  Reproduction in which an unfertilized egg develops into an adult animal
• Hermaphroditism


  Single organism produces both eggs and sperm
• Female reproductive anatomy


  • Ovaries
  • Oviducts and Uterus
  • Vagina and Vulva
  • Mammary glands

  
• Male reproductive anatomy


  • Testes
  • Ducts
  • Glands
  • Penis

  
• Movement of cells to form a tube such as the neural tube is an example of morphogenesis; specialization of cells to form neurons or some other cell types is called cellular differentiation
• Cleavage


  Rapid series of mitoses that converts the zygote to a morula
• Inner cell mass; embryo

  Cluster of cells that projects into the cavity of the blastocyst; gives rise to the embryo
• Gastrulation


  Process by which the blastula becomes a three-layered embryo
• Ectoderm; endoderm


  The three primary germ layers that form during gastrulation
• The growing nodes of embryonic tissue found at the shoot and root tips of a plant are its apical meristems

  
• In the grass seed, the cotyledon is a food-absorbing structure known as a scutellum
• The portion of the seedling below the cotyledons is known as the hypocotyl; one of the structures included in it is the future root, or radicle

  
• The root hairs form in the zone of maturation of the growing root tip
• When the "hook" of a dicot seedling is exposed to light during germination, it reacts by straightening; the receptor substance that initiates this reaction is a pigment known as phytochrome
• Amniotic fluid


  • Morphogenesis
  • Cellular differentiation
  • Newborn
  • Infant
  • Inner cell mass
  • Embryo
  • Placenta
  • Production of milk
• Movement of cells to form a tube

  Morphogenesis
• Specialization of cells to form neurons or other cell types

  Cellular differentiation
• Rapid series of mitoses that converts zygote to morula

  Cleavage
• Cluster of cells that projects into cavity of blastocyst

  Inner cell mass
• Cluster of cells that gives rise to embryo


  Inner cell mass