Ib Biology Practice Question (Core) Study Guide Rated A+

Some plant families, such as the figwort family, have been reclassified on the basis of evidence from cladistics. Explain the methods that have been used recently to reclassify groups of plants. {Ans: «previous» classification used to be based on the appearance/structures of the plant/leaves/flowers/seeds/analogy/phenotype «modern cladistics uses» RNA/DNA nucleotide/base sequencing/amino acid sequencing/homology DNA mutation occurs at a relatively constant rate allowing estimation of when species diverged a shared/common derived characteristic places organisms in the same clade the number of changes in sequences indicates distance from common ancestor OR the fewer the differences «in sequences» means the closer the relationship}Suggest possible reasons for the difficulty of preventing or controlling a viral epidemic in a remote rural region {Ans: poor transport infrastructure/poor communication/bad roads/difficult access/no maps/support slow arriving/scattered population poor education/understanding of disease amongst health workers/local population OR continued contact with infected people / other example of unsafe actions more sources of infection such as bats/difficult to find sources of infection lack of/limited access to medical care/doctors/health care workers lack of/no access to/unaffordability of treatment centers/medical supplies/equipment/antivirals/drugs/vaccine/treatments refusal/reluctance in local population to be vaccinated OR difficult to find/reach everyone to vaccinate them/repeat the vaccination migration of people spreads the infection