Recent Genetic Studies of the Structure of Microsporidian Genomes, as Well

question 84

Multiple Choice

Recent genetic studies of the structure of microsporidian genomes, as well as the sequences of their tubulin genes and the gene for RNA polymerase II, indicate that microsporidians are closely related to the fungi. Microsporidians lack flagella, centrioles, peroxisomes, and mitochondria (although they do have degenerate mitochondria, called mitosomes) . They have the smallest genome of any eukaryote, and it is a genome that changes quickly. The genome is contained within two haploid nuclei. All microsporidians are obligate intracellular parasites. They use a unique organelle called a polar filament to gain access to the cells of their hosts. One species causes chronic diarrhea in AIDS patients. Another parasitizes Anopheles gambiae, the mosquito that transmits a fatal form of malaria to humans.
-Given the eukaryotic structures they lack, it should be expected that microsporidians also lack

• A) the "9 + 2 pattern" of microtubules.
• B) chitin.
• C) lysosomes.
• D) nuclei.
• E) centrosomes.

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Definitions:

Cerebrum

A large, convoluted subdivision of the vertebrate brain; in humans, it functions as the center for learning, voluntary movement, and interpretation of sensation.

Primates

An order of mammals including humans, apes, monkeys, and prosimians, characterized by large brains, forward-facing eyes, and complex social behaviors.

Complex Curvature

A characteristic of a geometrical shape or object that has multiple curves or bends, often relating to advanced mathematics or physical shapes in architecture and design.

Spine

A leaf that is modified for protection, such as a cactus spine.