Exam 2 Test 2

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

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

Phytophthora

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

The choanoflagellates, fungi, and ______ are the major groups classified as opisthokonts (within the Unikont supergroup).

animals

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

brown algae

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 waxy layer that covers aerial parts of plants is the ______.

cuticle

Molecular evidence supports the view that all plastids evolved from an ancient ______.

cyanobacteria

__________ are an informal group of primarily aquatic eukaryotic organisms with diverse body forms, types of reproduction, modes of nutrition, and lifestyles. The group, which includes algae, water molds, slime molds and protozoa, is made up of unicellular, colonial, and simple multicellular organisms.

cyanobacteria

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

The plant life cycle alternates between ______ and ______ generations.

haploid, diploid

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

lignin

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

malaria

Plasmodial slime molds feed as ______ plasmodia.

multi-nucleate

In a coenocytic cell, multiple ______ in a common cytoplasm control all cellular activities in a concerted effort.

nuclei

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

red algae and green algae

Although many protists are free-living, others form stable _____ associations with unrelated organisms. These intimate association 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