YI

• Plant


  Transports food, water, and minerals through its systems
• Important parts of a plant

  • Roots
  • Stems
  • Leaves
  • Flower
  • Bud (apical)
  • Node (where stems/leaves bud)
  • Leaf Blade
  • Top Root
  • Lateral Root
• Shoot System


  Parts of a plant that are found above ground
• Root System


  Parts below the ground
• Leaves


  • Have cuticles that prevent the dehydration and withering of plants
• Parts of a xylem


  • Pit - allows water transport
  • Vessel Element - dies as a plant matures, causing dip hollows in trees
  • Tracheids - as thin as hair
  • Xylem Parenchyma Cell
• 1st Hypothesis: Root Pressure

  1. Water is collected at the roots

  2. Water flows in, creating pressure

  3. The previous pressure creates an upward flow of water
• Guttation


  Exudes water from the margins of the leaf instead of the stomata
• Straw Analogy

  • Water moves through roots by osmosis
  • Intake of water in roots increases the water potential
  • When stomata is closed at night, guttation occurs
  • Leaf margins must exude water as if too much water is evaporated, the plant will dehydrate
• 2nd Hypothesis: Capillary Action

  1. Surface Tension - forms between hydrogen molecules

  2. Adhesion - Molecular attraction between unlike molecules

  3. Cohesion - molecular attraction in like molecules
• Cohesion-Adhesion


  Combined capillary action & transpiration (occurs in stomata)
• Meniscus


  • Evaporation of water leads to this
  • It is a concave shape formed due to the tension or air left in the position where water used to be
• Phloem


  Transports sugar/other components
• Parts of Phloem


  • Sieve Pore
  • Companion Cell - does not participate in the transport of sugar. Instead, it supports the sieve tube by metabolism and regulation
  • Phloem Parenchyma
  • Sieve tube elements
• Sugar Source


  Where sugar is produced; usually leaves
• Sugar Sink


  Consumes or stores sugar; usually roots, stems, buds, and fruits
• Sugar sinks and sources can change depending on the seasons and stages of development
• Pressure


  It is created at the source while producing sugar. It then decreases at the sink as it is used
• Translocation


  Moves the sugar in the phloem to the parts that need it
• End of Dormancy Period


  The plant withers due to the onset of a new season
• Growing Period


  Parts of plants that were sugar sinks become the sugar sources
• Pressure Flow Model


  1. A high concentration of sugar at the source leads to low solute potential

  2. The potential results in movement from xylem to phloem. This movement creates high pressure potential called "high turgor pressure" within the phloem

  3. High turgor pressure moves phloem sap from source to sink by "bulk flow"

  4. Bulk flow helps sugars be rapidly removed from the sink, increasing the solute potential, forcing the water to move from phloem back to the xylem, leading to a lower solute potential
• Dicot


  Vascular bundle with a ring-like structure
• Monocot


  Vascular bundle with scattered structure
• 17 Elements for Growing Plants

  • Macronutrients from air and water: Carbon, Hydrogen, Oxygen
  • Macronutrients from soil: Nitrogen, Phosphorous, Potassium, Calcium, Magnesium
  • Micronutrients in Soil: Boron, Chlorine, Copper, Iron, Manganese, Molybdenum, Nitrogen, Zinc
• Nectarine


  Phytohormones released by certain trees that attract insects such as red ants
• Types of Reproduction


  • Asexual
  • Sexual
• Asexual Reproduction


  • Fission (binary fission)- prokaryotic microorganisms split into two separate organisms.
  • Budding - results from the outgrowth of a part of a cell or body region leading to a separation from the original
  • Fragmentation - breaking the body into two parts with subsequent regeneration.
  • Parthenogenesis- an egg develops into a complete individual without being fertilized. The resulting offspring can either be a haploid or diploid,
• Sexual Reproduction


  • Hermaphroditism
  • Separate Sexes
• External Fertilization


  Occurs outside the female body. This may be triggered by water temperature or length of daylight in aquatic creatures
• Internal Fertilization


  Occurs inside the female body. Most often found in land-based animals or in some aquatic animals
• Reproductive Modes


  • Oviparity
  • Ovoviviparity
  • Viviparity
• Parts of the Male Anatomy

  • External: Scrotum, Penis
  • Internal: Testes, Seminal Vesicles, Prostate gland, Bulbous urethral glands
• Female Reproductive Parts


  • Internal: Clitoris, Mons pubis, Labia Majora, Labia Minora
  • External: Ovaries, Fallopian Tube, Uterus, Vagina
• Hormonal Control of Human Reproduction

  • Negative feedback - normal biological response where every reaction regulates health by ensuring a reaction is appropriate and that all organs are in a constant state of homeostasis or equilibrium
  • Positive feedback - product reaction leads to an increase of that reaction
• Male Hormones


  • Testosterone
  • FSH
  • Inhibin
• Menstrual Cycle


  • Pituitary gland releases FSH and LH
  • Mature eggs develop and leave ovaries every 28 days. This is known as ovulation
  • If the egg is not fertilized, the built-up portion of the uterine wall will break down and shed along with the unfertilized egg and be released through the vagina. This starts the menstrual cycle
  • Menstrual cycle is different from ovulation
  • Menstrual cycle occurs if the egg is not fertilized after ovulation
  • Menstrual cycle begins at age 12 at the puberty stage. The first occurrence is known as menarche
  • The menstrual cycle temporarily stops during pregnancy and permanently stops at age 40 - 45
  • The menstrual cycle is controlled by the interactions of 4 hormones: Follicle-Stimulating Hormones (FSH), Luteinizing Hormone (LH), Estrogen, and Progesterone
• Menstrual Cycle Stages


  • Follicle Stage (Day 1 - Day 13)
• Ovulation


  Ovaries develop and release eggs every 28 days
• Uterine lining during ovulation

  • Thickens with a rich supply of blood vessels in preparation for a fertilized egg