Exam 2 Test 1

In 1977, Carl Woese and his coworkers overturned a universally held assumption about the basic structure of the tree of life. They showed that one group of microbes, the ______, are as distinct from bacteria as plants and animals. Having defined _____ as a new domain (one of the three domains), Woese redrew the taxonomic tree. Woese is famous for defining the ______ by using phylogenetic taxonomy of 16S ribosomal RNA, a technique that he pioneered which revolutionized the disciplines of microbiology and systematics. He is also the originator of the RNA world hypothesis.

Archaea

caused by the apicomplexan Plasmodium falciparum, that spends part of its life cycle in the Anopheles mosquito and part in humans

Malaria

The Irish potato famine of the 19th century was precipitated by an Oomycete in the genus _____, which causes late blight of potato.

Phytophthora

________ proposed a set of guidelines to demonstrate that a specific pathogen causes specific disease symptoms.

Robert Koch

In chapter seven of E.O. Wilson's book The Diversity of Life, ____ is the term applied to the spread of species of common ancestry into different niches.

adaptive radiation

Stomata ________.

allow gas exchange for photosynthesis

Cellular slime molds feed as individual ______ cells.

amoeboid

Kelps are _____ with multicellular bodies differentiated into blades, stripes, holdfasts, and gas-filled floats.

brown algae

Plants probably descended from a group of green algae called _____.

charophytes

Animals, fungi and most bacteria are known as _____, because they obtain energy from chemicals (typically by redox reactions), and because they cannot fix carbon; they use organic molecules produced by other organisms as the building blocks from which they synthesize the carbon compounds they need.

chemoheterotrophs

Ciliates use _____ for locomotion.

cilia

Most ciliates, such as Paramecium, are capable of a sexual process called ______, in which two individuals come together and exchange genetic material.

conjugation

The airtight, waterproof, waxy layer that covers aerial parts of plants is the ______.

cuticle

According to E.O. Wilson, one important way of describing diversity is by level of biological organization. The organizational levels of importance to biological diversity are arrayed in this hierarchy:

ecosystem, community, guild, species, organism, gene

Lynn Margulis is best known for her theory on the origin of eukaryotic organelles, and for her contributions to the ______, which is now a generally accepted explanation for how certain organelles were formed. She showed that animals, plants, and fungi all originated from protists. She is also associated with the Gaia hypothesis, based on an idea developed by the English environmental scientist James Lovelock.

endosymbiotic theory

Water molds (Oomycetes) are heterokonts, organisms that have two different kinds of _____.

flagella

Rhizobial bacteria ______.

form mutualistic relationships with the roots of legumes and fix nitrogen

A strengthening compound found in cell walls of vascular plants is ______.

lignin

Plasmodial slime molds feed as ______ plasmodia.

multi-nucleate

Microorganisms that cause disease are called _____.

pathogens

Some parasitic protists are important ______ (disease-causing agents) of plants and animals.

pathogens

The floating, often microscopic organisms that are the base of food webs in aquatic ecosystems are collectively called ______.

plankton

______ have cell walls with cellulose and characteristically obtain most of their energy from sunlight via photosynthesis using chlorophyll contained in chloroplasts, which gives them their green color. However, some are parasitic and may not produce normal amounts of chlorophyll or photosynthesize. They are also characterized by sexual reproduction, modular and indeterminate growth, and an alteration of haploid and diploid generations, although asexual reproduction is common.

plants

Amoebas move and obtain food by means of _____.

pseudopodia

According to Solomon et al., the monophyletic supergroup "Archaeplastids" includes _____.

red algae, green algae, and plants

Although many protists are free-living, others form stable _____ associations with unrelated organisms. These intimate associations range from mutualism, to commensalism, to parasitism.

symbiotic

In plant life cycles ______.

the first stage in the diploid sporophyte generation is the zygote

The _____ are specialized excavates that live in the guts of termites and wood-eating cockroaches. They ingest wood chips from the wood that termites or roaches eat and rely on endosymbiotic bacteria to digest cellulose in the wood. The insects, _____, and bacteria all obtain their nutrients from this source. This is an excellent example of mutualism.

trichonymphs

In chapter eight, Wilson considers the Earth's biosphere to be largely _____.

unexplored

Most dinoflagellates are a part of marine plankton. The _____ are endosymbiotic, photosynthetic dinoflagellates found in certain marine invertebrates; their mutualistic relationship with corals enhances the corals' reef-building ability.

zooxanthellae