DEPUGAAAA LASTT

• Plants have two systems for the transportation of substances, by using two different types of transport tissue
• Xylem


  Tubular-shaped structure, with the absence of cross walls, resembles the shape of a star
• Phloem


  Tubular-shaped, elongated, structures with the presence of walls with thin sieve tubes
• Differences between Xylem and Phloem


  • Location
  • Fibers
  • Found In
  • Movements
  • Comprises
  • No of Tissues
  • Features
  • Functions
  • Vascular Bundles
• Xylem transports soluble mineral nutrients and water molecules from the roots to the aerial parts of the plant
• Phloem transports food and other nutrients including sugar and amino acids from leaves to storage organs and growing parts of the plant
• Open circulatory system


  Blood vessels transport all fluids into a cavity, blood bathes the organs directly
• Closed circulatory system


  Blood is contained within blood vessels that transport blood to and from the heart
• Pulmonary circulation system


  1. Deoxygenated blood leaves the heart through the right ventricle and is transported to the lungs via the pulmonary artery

  2. Oxygen diffuses into the blood and is returned to the left atrium of the heart via the pulmonary vein
• Systemic circulation


  1. Blood leaves through the left ventricle into the aorta, the body's largest artery

  2. Blood moves into venules that merge into veins, and the blood is transported back to the heart
• Osmosis


  Movement of solvent molecules through a semipermeable membrane into an area that has a higher solute concentration
• Osmotic pressure


  External pressure needed to prevent the solvent from crossing the membrane
• Osmoregulation strategies of different organisms


  • Bacteria
  • Protozoa
  • Plants (mesophytes, xerophytes, halophytes, hydrophytes)
  • Animals
• In humans, the primary organs responsible for osmoregulation are the kidneys
• Xerophytes (plants in dry habitats)


  • Store water in vacuoles
  • Have thick cuticles
  • May have structural modifications (e.g. needle-shaped leaves, protected stomata) to protect against water loss
• Halophytes (plants in salty environments)


  • Have to regulate water intake/loss and the effect on osmotic pressure by salt
  • Some species store salts in their roots so the low water potential will draw the solvent in via osmosis
  • Salt may be excreted onto leaves to trap water molecules for absorption by leaf cells
• Hydrophytes (plants in water or damp environments)

  • Can absorb water across their entire surface
• Excretory system (in animals)


  • Controls the amount of water lost to the environment and maintains osmotic pressure
  • Protein metabolism generates waste molecules which could disrupt osmotic pressure
• Osmoregulation in humans


  • The kidney is the primary organ that regulates water
  • Water, glucose, and amino acids may be reabsorbed from the glomerular filtrate in the kidneys, or it may continue through the ureters to the bladder for excretion in urine
  • Maintains the electrolyte balance of the blood and regulates blood pressure
  • Absorption is controlled by the hormones aldosterone, antidiuretic hormone (ADH), and angiotensin II
  • Humans also lose water and electrolytes via perspiration
• Osmoreceptors


  • In the hypothalamus of the brain, monitor changes in water potential, controlling thirst and secreting ADH
  • ADH is stored in the pituitary gland and targets the endothelial cells in the nephrons of the kidneys
  • Endothelial cells have aquaporins which allow water to pass through directly rather than having to navigate through the lipid bilayer of the cell membrane
  • ADH opens the water channels of the aquaporins, allowing water to flow
  • The kidneys continue to absorb water, returning it to the bloodstream, until the pituitary gland stops releasing ADH
• Learning Competencies


  • Compare and contrast the following processes in plants and animals: Immune System, Chemical and Nervous Control, Sensory and Motor Mechanisms
  • Compare and contrast the following processes in plants and animals: Feedback Mechanisms
• Innate immunity


  Nonspecific defense mechanisms that come into play immediately or within hours of an antigen's appearance in the body
• Adaptive immunity


  Antigen-specific immune response
• Human antibody isotypes


  • IgM
  • IgD
  • IgG
  • IgA
  • IgE
• IgG


  Most abundant antibody isotype in the blood, detoxifies harmful substances and is important in the recognition of antigen-antibody complexes
• IgM


  Circulates in the blood, first produced by B cells in response to microbial infection/antigen invasion
• IgA


  Abundant in serum, nasal mucus, saliva, breast milk, and intestinal fluid, forms dimers
• IgE


  Present in minute amounts, originally to protect against parasites, now primarily involved in allergy
• IgD


  Accounts for less than 1% of human immunoglobulins, may be involved in the induction of antibody production in B cells
• T cell


  White blood cell of key importance to the immune system, at the core of adaptive immunity
• Main types of T cells


  • Cytotoxic
  • Helper
  • Regulatory
• Cytotoxic T cells


  Recognize and kill infected cells
• Helper T cells


  Recognize pathogen peptides displayed by antigen presenting cells and produce cytokines to signal to other immune cells
• Regulatory T cells


  Suppress the immune response to prevent excessive damage to normal cells and tissues
• Sensory transduction


  Process of converting different types of stimuli into the electrochemical signals of the nervous system
• Sensation


  Activation of sensory receptors at the level of the stimulus
• Perception


  Central processing of sensory stimuli into a meaningful pattern involving awareness
• Structural receptor types


  • Exteroceptor
  • Interoceptor
  • Proprioceptor
• Functional receptor types


  • Chemoreceptor
  • Osmoreceptor
  • Nociceptor
  • Mechanoreceptor
  • Thermoreceptor
• Types of eyes in the animal kingdom


  • Eye cups in flatworms and other invertebrates
  • Compound eyes in insects and arthropods
  • Single lens eyes in squid and other mammals