Flow-cytometric analysis for the detection and measurement of subpopulations of leukocytes, including those of leukaemia, is usually performed using monoclonal antibodies. Why is this the case?

Choose whether each of the following statements is true 

a) Indirect immunofluorescence is a more sensitive technique than direct immunofluorescence

b) Most antigens induce a polyclonal response. 

c) For precipitation to occur, both antigen and antibody must be multivalent.

d) ELISA tests using chemiluminescence are more sensitive than chromogenic ones and precipitation tests are more sensitive than agglutination tests

#Question id: 8682

#Unit 9. Diversity of Life Forms

Giardia intestinalis can cause disease in several different mammalian species, including humans. Giardia organisms (G. intestinalis) that infect humans are similar morphologically to those that infect other mammals, thus they have been considered a single species. However, G. intestinalis has been divided into different subgroups based on their host and a few other characteristics. In 1999, a DNA sequence comparison study tested the hypothesis that these subgroups actually constitute different species. The following phylogenetic tree was constructed from the sequence comparison of rRNA from several subgroups of G. intestinalis and a few other morphologically distinct species of Giardia. The researchers concluded that the subgroups of Giardia are sufficiently different from one another genetically that they could be considered different species

Which of the following changes would a modern systematist be most likely to make after learning of the results of the rRNA analyses?

#Question id: 8683

#Unit 9. Diversity of Life Forms

Use the following information to answer the question.

Refer to the figure. Which of the following forms a monophyletic group?

#Question id: 8684

#Unit 9. Diversity of Life Forms

Use the following information to answer the question.

Which of the following trees, if any, depicts the same relationship among species as shown above?

#Question id: 8685

#Unit 9. Diversity of Life Forms

Which of the following would be most useful in creating a phylogenetic tree of a taxon?

#Question id: 8687

#Unit 9. Diversity of Life Forms

Your professor wants you to construct a phylogenetic tree of orchids. She gives you tissue from seven orchid species and one lily. What is the most likely reason she gave you the lily?

#Question id: 8689

#Unit 9. Diversity of Life Forms

Which of the following statements best describes the rationale for applying the principle of maximum parsimony in constructing phylogenetic trees?