BIO 14 Exam 2

Imagine that you are treating patients with a serious viral infection. You determine that the patients' immune system is unable to easily detect the presence of the virus, and so you conclude that the virus is most likey possesses which of the following features?

a membranous envelope

If the mitochondria and chloroplasts in eukaryotic cells resulted from endosymbiosis, what features might we expect these organelles to contain?

a plasma membrane, DNA, and ribosomes

Imagine you are investigating the cause of a disease that impairs the function of nervous tissue. To find the pathogen that causes the disease, you extract DNA and RNA from infected nervous tissue so you can determine whether the pathogen is closely related to any known pathogens. To your surprise, you find that the extracted DNA and RNA belong only to the host. Given this result, what can you conclude?

The disease may be caused by a prion.

Many protists such as dinoflagellates, stramenopiles, and euglenids contain plastids that have three or even four membranes, as well as DNA similar to that of cyanobacteria. A hypothesis that explains these characeristics is:

endosymbiosis

The food-absorbing part of a fungus (as opposed to the reproductive structure) is called the:

mycelium

It is thought that many protists evolved from a symbiotic relationship that formed when a heterotrophic eukaryote engulfed a prokaryote. This process is called:

primary endosymbiosis

Various species of fungi can be used to do all of the following except: a) produce biofuels b) produce antibiotics c) produce oxygen as a byproduct of photosynthesis d) make certain kinds of cheese e) study genes similar to those that cause genetic diseases in humans

produce oxygen as a byproduct of photosynthesis

One of the most significant beneficial roles of protists in the biosphere is their action as:

producers

Occasionally, bacterial DNA is transferred from one cell to another by a bacteriophage. This process is called:

transduction

Suppose that you are treating a patient who has a bacterial infection that is highly resistant to antibiotic treatment. Which of the following traits is this bacterial strain likely to possess?

All of theses are traits are likely in antibiotic-resistant bacteria: capsule endospore Gram negative R-plasmid (plasmid with resistance genes)

Which of the following is true of archaeans? a) They are easily cultured in the lab. b) They exist only as symbionts within other organisms. c) They are very common and are found in all environments. d) Most of them are extremophiles.

They are very common and are found in all environments.

Which of the following is true of mycorrhizae? a) They fix atmospheric nitrogen, making it available to plants. b) They make phosphate available to plants and increase surface area for water absorption c) They are harmful to the roots of plants, often killing the host plant that they infect. d) Only a few vascular plants have mycorrhizae, but these include important food crops such as wheat and corn.

They make phosphate available to plants and increase surface area for water absorption

Some archaeans are extremophiles, such as those that survive very high temperatures or extremely salty conditions. An archaean that can survive a very low pH might be called a/n:

acidophile

Which of the following is NOT a role of bacteria in the ecosystem? a) producers b) pathogens c) symbionts d) decomposers e) all

all of these are roles of bacteria: producers pathogens symbionts decomposers

The cell walls of fungi are composed of:

chitin

Which of the following structures is NOT included in any virus? a) cytoplasm b) DNA c) membranous envelope d) RNA e) capsid proteins

cytoplasm

Multicellular fungi are made up of numerous thin filaments called:

hyphae

Which of the following is NOT a difference between Archaea and Bacteria? a) number of RNA polymerases b) presence of peptidoglycan c) presence of introns in genes d) lack of a nucleus e) presence of histones in DNA

lack of a nucleus

Certain fungi form mutualistic symbioses with a photosynthetic partner such as a protist or cyanobacterium. These are commonly known as _________________.

lichens

Which of the following is a trait shared by prokaryotes and eukaryotes, but not by viruses? a) nucleic acids used to store hereditary information. b) the ability to process energy through metabolic reactions. c) the capacity to evolve. d) complex and ordered arrangements of macromolecules.

the ability to process energy through metabolic reactions