Ch 11

• • Every organism has unique molecules on the surface of its cells
• • Pathogens can be species-specific although others can cross species barriers
• • B lymphocytes are activated by T lymphocytes in mammals
• • Activated B cells multiply to form clones of plasma cells and memory cells
• • Plasma cells secrete antibodies
• • Antibodies aid the destruction of pathogens. (Y shape clumps pathogens together)
• • White cells release histamine in response to allergens
• • Histamines cause allergic symptoms
• • Immunity depends upon the persistence of memory cells
• • Vaccines contain antigens that trigger immunity but do not cause the disease
• • Fusion of a tumour cell with an antibody-producing plasma cell creates a hybridoma cell.
• • Monoclonal antibodies are produced by hybridoma cells
• • Application: Smallpox was the first infectious disease of humans to have been eradicated by vaccination.
• • Application: Monoclonal antibodies to HCG are used in pregnancy test kits
• • Application: Antigens on the surface of red blood cells stimulate antibody production in a person with a different blood group.
• • Bones and exoskeletons provide anchorage for muscles and act as levers
• • Synovial joints allow certain movements but not others
• • Movement of the body requires muscles to work in antagonistic pairs
• • Skeletal muscle fibres are multinucleate and contain specialized endoplasmic reticulum
• • Muscle fibres contain many myofibrils
• • Each myofibril is made up of contractile sarcomeres
• • The contraction of the skeletal muscle is achieved by the sliding of actin and myosin filaments
• • ATP hydrolysis and cross bridge formation are necessary for the filaments to slide.
• • Calcium ions and the proteins tropomyosin and troponin control muscle contractions.
• • Application: Antagonistic pairs of muscles in an insect leg
• • Skill: Annotation of a diagram of the human elbow
• human elbow diagram

  A) humerus

  B) radius

  C) ulna

  D) tricep

  E) biceps

  F) synovial

  G) cartilage

  H) capsule

  
• • Drawing labelled diagrams of the structure of a sarcomere.

  
• • Skill: Analysis of electron micrographs to find the state of contraction of muscle fibres.

  
• • Measurement of the length of sarcomeres will require calibration of the eyepiece scale of the microscope.
• • Animals are either osmoregulators or osmoconformer
• • The Malpighian tubule system in insects and the kidney carry out osmoregulation and removal of nitrogenous wastes.
• • The composition of blood in the renal artery is different from that in the renal vein.
• • The ultrastructure of the glomerulus and Bowman’s capsule facilitate ultrafiltration.
• • The proximal convoluted tubule selectively reabsorbs useful substances by active transport.
• • The loop of Henle maintains hypertonic conditions in the medulla
• • ADH controls reabsorption of water in the collecting duct
• • The length of the loop of Henle is positively correlated with the need for water conservation in animals (longer in desert animals)
• • The type of nitrogenous waste in animals is correlated with evolutionary history and habitat
• • Application: Consequences of dehydration and overhydration