BIOL1202 FINAL

• Derived Characters of Chordates


  • Notochord
  • Dorsal, hollow nerve cord
  • Pharyngeal slits or clefts
  • Muscular, post-anal tail
• Hagfishes (Myxini)


  Jawless vertebrates that have a cartilaginous skull, reduced vertebrae, and a flexible rod of cartilage derived from the notochord
• Hagfishes


  • They have a small brain, eyes, ears, a nasal opening, and tooth-like formations in their mouths
  • All are marine; most are bottom-dwelling scavengers
  • Produce slime to repel competitors and predators
• Lampreys (Petromyzontida)


  Jawless vertebrates that inhabit SW & FW habitats
• Lampreys


  • Some are parasites that feed by clamping their mouths onto a live fish
  • Free-living species feed as larvae for several years and then mature, reproduce, and die within a few days
  • Have a notochord and cartilaginous skeleton
• Characteristics of most fishes


  • They breathe by drawing water over gills protected by an operculum
  • They control their buoyancy with an air sac known as a swim bladder
  • Their skin secretes mucus and is covered by flattened, bony scales
  • Most species are oviparous, but some have internal fertilization and birthing
• Figure 34.23


  • (a) The tadpole
  • (b) During metamorphosis
  • (c) The adults return to water to mate
• Amniotic egg


  A key adaptation to life on land
• Amniote adaptations


  • Relatively impermeable skin
  • Ability to use the rib cage to ventilate the lungs
• Toxin


  A chemical substance produced within living cells or organisms
• Poison


  A substance that can cause illness or death when absorbed or ingested
• Venom


  A substance produced by an animal for self defense & injected into another animal
• Derived characters of mammals


  • Mammary glands, which produce milk
  • Hair and a fat layer under the skin for insulation
  • Kidneys, which conserve water from wastes
  • Endothermy and a high metabolic rate
  • Efficient respiratory and circulatory systems
  • A large brain-to-body-size ratio
  • Extensive parental care
  • Differentiated teeth
• Synapsids


  Mammals belong to this group of amniotes
• Mammalian lineages


  • Monotremes
  • Marsupials
  • Eutherians
• Monotremes


  • Females lack nipples and secrete milk from glands on their bellies; the baby sucks milk from the mother's fur
• Marsupials


  • The embryo develops within the mother's uterus and is nourished by the placenta
  • A marsupial is born very early in its development and completes its embryonic development while nursing in a maternal pouch called a marsupium
• Living primate groups


  • Lemurs, lorises, and bush babies
  • Tarsiers
  • Anthropoids (monkeys and apes)
• Animal tissue types


  • Epithelial
  • Connective
  • Muscle
  • Nervous
• Connective tissue cell types


  • Fibroblasts: secrete the protein of extracellular fibers
  • Macrophages: involved in the immune system
• Connective tissue types


  • Loose tissue
  • Fibrous tissue
  • Bone
  • Adipose tissue
  • Blood
  • Cartilage
• Nervous tissue


  Functions in the receipt, processing, and transmission of information
• Nervous tissue components


  • Neurons, or nerve cells, which transmit nerve impulses
  • Glial cells, or glia, which support cells
• Negative feedback


  Helps to return a variable to a normal range
• Positive feedback


  Amplifies a stimulus and does not usually contribute to homeostasis in animals
• Poikilotherm


  Body temperature varies with its environment
• Homeotherm


  Body temperature is relatively constant
• Heat exchange processes


  • Radiation
  • Evaporation
  • Convection
  • Conduction
• Thermoregulation adaptations


  • Insulation
  • Circulatory adaptations
  • Cooling by evaporative heat loss
  • Behavioral responses
  • Adjusting metabolic heat production
• Essential fatty acids must be obtained from the diet and include certain unsaturated fatty acids
• Intracellular digestion


  Food particles are engulfed by phagocytosis and liquids by pinocytosis
• Extracellular digestion


  Breakdown of food particles outside of cells, in compartments that are continuous with the outside of the animal's body
• Gastrovascular cavity


  Functions in both digestion and distribution of nutrients
• Complete digestive tract


  A digestive tube with two openings, a mouth and an anus
• Mammalian accessory glands


  • Salivary glands
  • Pancreas
  • Liver
  • Gallbladder
• Swallowing


  Causes the epiglottis to block entry to the trachea, and the bolus is guided by the larynx, the upper part of the respiratory tract
• Peristalsis


  Rhythmic contractions of muscles in the wall of the esophagus that push food along
• Sphincters


  Valves that regulate the movement of material between compartments
• Chyme


  The mixture of ingested food and gastric juice
• Gastric ulcers


  Lesions in the lining of the stomach, caused mainly by the bacterium Helicobacter pylori