The exoskeleton and metamorphosis in insects

Question 1

Which way does the heart pump blood in insects?

Answer 1

Back-front

Question 2

What are the advantages of external exoskeletons?

Answer 2

. Enhanced leverage for muscular movements
. Protective covering for muscles and internal organs
. Restriction of moisture loss in terrestrial habitats (deserts/cuticle reduces water loss
. Coverage for compound eyes (cuticle advantages)
. Ability to produce both rigid jointed appendages for walking, jumping or capturing prey and membranous, foldable sheets for flying, lenses for compound eyes

Question 3

What are the disadvantages of external exoskeletons?

Answer 3

. Vulnerability during the moulting process (restricts growth)
. Restrictions in term of large size and weight mainly due to the inability of oxygen to reach metabolically active tissues in very large insects (cuticle starts soft and gets harder