Exam 17: Annelids and Allied Taxa

The most recent molecular evidence suggests that the Annelida and Mollusca are more closely related to each other (in the clade Lophotrochozoa)rather than either phylum is to the Arthropoda (clade Ecdysozoa).Do you think 1)it matters that this distinction is made,and 2)should the use of molecular evidence by itself be the sole means of distinguishing the affinities of these groups? Support your argument.

When earthworms mate,the _______________ secretes mucus to hold them together.

Each internal compartment of an annelid is lined with

Conventional external fertilization involves both males and females extruding gametes into the environment where they fertilize separate from the parents; internal fertilization involves sperm being transferred to the female with fertilization inside the female.A leech utilizes

The Branchiobdellida,is a group of small annelids that contains parasites or commensals of crayfish.They show similarities to both oligochaetes and leeches in that they bear a head sucker.In your analysis,is the evolution of a head sucker a derived trait in an oligochaete lineage or would the loss of posterior sucker place them in the Hirudinea?

Discuss why segmentation is such an important innovation in the Annelida.

Members of the clade Siboglinidae are also known as the

Polychaetes differ from other annelids because polychaetes

The Formation of Vegetable Mould Through the Action of Worms is the title of a classic study by Charles Darwin.What is the true role of earthworms in soil formation?

Paired appendages used for locomotion in polychaetes are called ___________________.

The body wall of an annelid consists of

The high degree of development of eyes in the family Alciopidae is related to

The evolutionary position of leeches is best described as

A robin has difficulty pulling an earthworm from its earthen burrow because of small chitinous bristles called

The temporary food storage organ in the earthworm is the _________________.

A biologically plausible reason that burrowing earthworms have solid segmental walls but nonburrowing and parasitic annelids often have partial septa is

____________ organs are ciliated sensory pits or slits that appear to be chemoreceptive for food gathering.

The spaces in the coelom of leeches are called the _______________.