BIOLOGY

• Reproduction


  The biological process by which offspring are produced from their parent or parents
• Types of reproduction

  • Asexual reproduction
  • Sexual reproduction
• Asexual reproduction


  • Does not involve gametes, instead parts of mature organism may develop to new individuals
  • Offspring is genetically identical to the parent
• Binary fission


  1. Separation of the body into two new bodies

  2. Common in single-celled organisms
• Budding


  1. A new organism develops from as an outgrowth from the parent body known as bud

  2. Once grown, the new organisms detaches from the parent body
• Organisms with asexual reproduction

  • Hydra
  • Saccharomyces cerevisiae
• Fragmentation


  The parent body will break into several pieces where each piece grows into a new individual
• Vegetative propagation


  1. A plant part such as stems, leaves, roots or turions are used to reproduce new plant

  2. Natural vegetative propagation (without human interference)

  3. Artificial vegetative propagation (with the need of human interference)
• Sexual reproduction


  • Use of sex cells (gametes)
  • Involves the fusion of male and female gametes to form a zygote
  • Genetic variability
• Gametogenesis


  Production of gametes
• Blastocyst

  • Will secrete HCG (hormone used to detect pregnancy)
  • Progesterone level is very high to prevent menstruation
• Embryonic stage


  1. Formation of 4 membranes that supports, protects and nourish the embryo (yolk sac, allantois, amnion and chorion)

  2. Development of placenta

  3. Organ formation
• Fetal stage


  Organs differentiate further and grow
• Gonadotropin-releasing hormone (GnRH)


  Stimulates the release of 2 hormones: Luteinizing hormone (LH) and Follicle-Stimulating Hormone (FSH)
• Follicle-Stimulating Hormone (FSH)


  Male: It causes the testes to produce sperm

  Female: it causes the growth of an ovarian follicle and it causes the follicle cells to secrete estrogen
• Luteinizing hormone (LH)


  Male: It causes the testes to secrete testosterone

  Female: it causes ovulation and to secrete progesterone
• Stamen


  • Male portion of a flower
  • Made up of an anther and a filament
  • The anther produces haploid pollen grains by meiosis
  • Most flowers have multiple stamens
• Carpel/Pistil


  • Female portion of a flower
  • Stigma - sticky; to trap pollen
  • Style - hollow tube which connects stigma and ovary
  • Ovary - produces female gametes (ovules)
• Nutrition


  Nutrients help living organisms develop their bodies, grow, heal damaged body parts and give energy for life and activity
• Monoecious


  • Stamens and pistils occur on separate flowers, but the same plant
• Dioecious


  • Staminate and pistillate flowers occur on separate plants
• Modes of Nutrition

  • Autotrophic Nutrition
  • Heterotrophic Nutrition
• Gametophyte


  Stage of the life cycle of a plant that is haploid; stage that produces gametes via mitosis; these gametes fuse to form a zygote that develops into a sporophyte
• Sporophyte


  Stage of the life cycle of a plant that is diploid; it is the most recognizable structure in most flowering plants; it produces haploid spores by meiosis in structures called sporangia
• Autotrophic Nutrition


  Can produce their own food
• Male gametophyte

  Inside the anthers' microsporangia, male gametophytes divide by meiosis to generate haploid microspores, which, in turn undergo mitosis and give rise to pollen grains (containing 2 sperm nuclei and tube nucleus)
• Pollen grains


  Contains two cells: one generative cell and one cell that will become the pollen tube cell
• Heterotrophic Nutrition


  Cannot produce their own food
• Female gametophyte

  The ovule inside the ovary contains the megasporangium

  Within each mega sporangium, a megasporocyte undergoes meiosis generating four(4) megaspores; three (small) and one (1) large
• Digestion


  The mechanical and chemical processes by which complex food substances are broken down into simpler substances
• Pollination


  The transfer of pollen from an anther to a receptive stigma

  Agents: Animals, wind, water, humans
• Parts of the Digestive System

  • Mouth
  • Esophagus
  • Stomach
  • Liver
  • Pancreas
  • Gall bladder
  • Small Intestine
  • Large Intestine
  • Anus
• Fertilization


  One egg and sperm combine, forming a diploid zygote, the future embryo

  Double fertilization - fuses with the polar nuclei to become the endosperm, which serves as food of the early embryo
• Embryo development


  Ovules become the seed

  Ovary matures into fruit
• Mouth


  Produces saliva where mechanical mastication of food takes place to form bolus
• Seed germination

  Germination - is the resumption of growth and development after a period of seed dormancy

  Epigenous germination

  Hypogenous germination
• Esophagus


  A muscular tube that conducts peristalsis and serves a passage way for food
• Hormonal regulation of plant growth and development
• Stomach


  A muscular sac that contains gastric juices that helps to break down the food chemically
• Liver


  Produces the bile that helps in the digestion of fats