Describe the functioning of immunoglobulins.

Outline how antibiotics offer protection from certain forms of infectious disease.

Coughing to clear the airways is accomplished by muscle contractions. Explain muscle contraction.

a. «immumoglobulins are/function as» antibodies 

b. variety of binding sites / variable regions for binding 

c. specific to antigens on bacteria/viruses/pathogens 

d. constant region aids destruction of the bacteria/virus/pathogen 

e. attracts phagocytes/macrophages to engulf pathogen 

f. bursting pathogen cells/agglutination/neutralizing toxins/other example of the action of antibodies

Award marks for an annotated diagram.

a. protect against/kill/inhibit growth of microorganisms/bacteria/prokaryotes 

b. bacteria/prokaryote processes blocked but not processes in eukaryotes/other organisms 

c. block metabolic pathways/DNA replication/DNA transcription/translation/ribosome functioning/cell wall formation 

d. do not protect against viruses as they have no metabolism/are non-living 

e. antibiotics fail to protect if bacteria have resistance 

f. can be used in humans/animals because antibiotics do not affect eukaryotic cells/bacterial metabolism is different

a. myofibrils «in muscle fibers/cells» 

b. sarcomeres «are the repeating units in muscle/myofibrils» 

c. sarcomeres arranged end to end / sarcomeres shorten during muscle contraction 

d. actin and myosin/overlapping protein filaments/diagram to show sarcomere with actin and myosin overlapping 

e. dark and light bands «in sarcomeres»/diagram to show this/light bands narrower when muscle is contracted 

f. thick filament is myosin and thin filament is actin/diagram to show this 

g. nerve impulses stimulate contraction/cause depolarization of sarcolemma/T-tubules/trigger release of calcium from sarcoplasmic reticulum 

h. calcium ions released from sarcoplasmic reticulum/bind to troponin 

i. troponin causes tropomyosin to move/exposes binding sites on actin 

j. myosin «heads» form cross bridges with/bind to actin 

k. myosin heads move/change angle/swivel/cock / myosin heads cause the power stroke 

l. myosin filaments pull actin towards center of sarcomere/more overlap between actin and myosin/Z-lines move closer 

m. ATP is used «to provide energy»/cause cross-bridges to break/cause movement of myosin heads/cause filaments to slide/cause muscle contraction 

n. intercostal/abdominal/diaphragm muscles contract «to cough»

Marks can be awarded for any point made clearly on an annotated diagram.