Exam 2-Mastering Biology Questions Flashcards
RNA molecules can both carry genetic information and be catalytic. This supports the proposal that:
A. protobionts had an RNA membrane
B. free nucleotides would not have been necessary ingredients in the synthesis of new RNA molecules
C. RNA is a polymer of amino acids
D. RNA could make energy
E. RNA was the first hereditary information
E. RNA was the first hereditary information (Because RNA can catalyze synthesis of new RNA)
Approximately how far back in time does the fossil record extend?
A. 3,500,000 years
B. 3,500,000,000 years
C. 5,000,000,000 years
D. 6,000,000 years
E. 6,000 years
B. 3,500,000,000
An early consequence of the release of oxygen gas by plant and bacterial photosynthesis was to:
A. cause iron in ocean water and terrestrial rocks to rust (oxidize)
B. make it easier to maintain reduced molecules
C. change the atmosphere from oxidizing to reducing
D. make life on land difficult for aerobic organisms
E. prevent the formation of an ozone layer
A. cause iron in ocean water and terrestrial rocks to rust (oxidize)
Which free-living cells were the earliest contributors to the formation of Earth’s oxidizing atmosphere?
A. seaweeds
B. mitochondria
C. cyanobacteria
D. endosymbionts
E. chloroplasts
C. cyanobacteria
Which of the following statements provides the strongest evidence that prokaryotes evolved before eukaryotes?
A. meteorites that have struck Earth
B. the primitive structure of plants
C. Liposomes closely resemble prokaryotic cells
D. abiotic laboratory experiments that produced liposomes
E. the oldest fossilized cells resemble prokaryotes
E. the oldest fossilized cells resemble prokaryotes
What is thought to be the correct sequence of these events, from earliest to most recent, in the evolution of life on Earth? 1. origin of mitochondria 2.origin of multicellular eukaryotes 3. origin of chloroplasts 4. origin of cyanobacteria 5. origin of fungal-plant symbioses
A. 4, 3, 2, 1, 5
B. 4, 3, 1, 5, 2
C. 4, 1, 2, 3, 5
D. 4, 1, 3, 2, 5
E. 3, 4, 1, 2, 5
D. 4, 1, 3, 2, 5 (cyanobacteria > mitochondria > chloroplasts > multicellular eukaryotes > fungal-plant symbioses)
Penicillin is an antibiotic that inhibits enzymes from catalyzing the synthesis of peptidoglycan, so which prokaryotes should be most vulnerable to inhibition by penicillin?
A. gram-positive bacteria
B. archaea
C. endospore-bearing bacteria
D. gram-negative bacteria
E. mycoplasmas
A. gram-positive bacteria (because what makes cells gram-positive is their lack of a lipopolysaccharide membrane above the peptidoglycan membrane. This would make it so the antibiotic could break down the cell membrane)
Which two structures play direct roles in permitting bacteria to adhere to each other, or to other surfaces?
A. capsules and fimbriae
B. capsules and endospores
C. fimbriae and flagella
D. fimbriae and plasmids
E. endospores and fimbriae
A. capsules and fimbriae
The typical prokaryotic flagellum features:
A. an internal 9+2 pattern of microtubules
B. a complex “motor” embedded in the cell wall and plasma membrane
C. an external covering provided by the plasma membrane
D. a basal body that is similar in structure to the cell’s centrioles
B. a complex “motor” embedded in the cell wall and plasma membrane
An organism that obtains its energy from chemicals:
A. autotroph only
B. heterotroph only
C. chemotroph only
D. phototroph only
E. autotroph and chemotroph
C. chemotroph only
A prokaryote that obtains both energy and carbon as it decomposes dead organisms:
A. chemotroph only
B. autotroph only
C. autotroph, phototroph, and chemotroph
D. autotroph and phototroph
E. heterotroph and chemotroph
E. heterotroph and chemotroph
Protists are alike in that all are:
A. symbionts
B. monophyletic
C. autotrophic
D. eukaryotic
E. unicellular
D. eukaryotic
According to the endosymbiotic theory of the origin of eukaryotic cells, how did mitochondria originate?
A. from the nuclear envelope folding outward and forming mitochondrial membranes
B. from infoldings of the plasma membrane, coupled with mutations of genes for proteins in energy-transfer reactions
C. by secondary endosymbiosis
D. when a protoeukaryote engaged in a symbiotic relationship with a protobiont
E. from engulfed, originally free-living prokaryotes
E. from engulfed, originally free-living prokaryotes
The chloroplasts of land plants are thought to have been derived according to which evolutionary sequence?
A. cyanobacteria > green algae > land plants
B. red algae > cyanobacteria > land plants
C. red algae > brown algae > green algae > land plants
D. cyanobacteria > red algae > green algae > land plants
E. cyanobacteria > green algae > fungi > land plants
A. Cyanobacteria > green algae > land plants
Which taxon of eukaryotic organisms is thought to be directly ancestral to the plant kingdom?
A. radiolarians
B. apicomplexans
C. golden algae
D. green algae
E. foraminiferans
D. green algae
Which is the correct sequence of these events in the origin of life? 1. formation of protobionts 2. synthesis of organic monomers 3. synthesis of organic polymers 4. formation of DNA-based genetic systems
A. 3, 2, 1, 4
B. 2, 3, 1, 4
C. 1, 2, 3, 4
D. 4, 3, 1, 2
E. 1, 3, 2, 4
B. 2, 3, 1, 4 (organic monomers > organic polymers > protobionts > DNA-based genetic systems)
Which is a defining characteristic that all protobionts had in common?
A. a surrounding membrane or membrane-like structure
B. a nucleus
C. the ability to replicate RNA
D. RNA genes
E. the ability to synthesize enzymes
A. a surrounding membrane or membrane-like structure
Which of these is a receptor molecule?
B
A signal transduction pathway is initiated when a _____ binds to a receptor.
G protein
cyclic AMP
signal molecule
calmodulin tyrosine kinase
Signal Molecule
Which of these is a signal molecule?
A
A signal molecule is also known as a(n) _____.
ligand key protein initiator receptor
Ligand
Which of these is the second of the three stages of cell signaling?
gene activation reception binding of a neurotransmitter to a plasma membrane receptor transduction cell response
Transduction
Which of the following is a type of local signaling in which a cell secretes a signal molecule that affects neighboring cells?
synaptic signaling hormonal signaling autocrine signaling paracrine signaling
Paracrive Signaling
Hormones are chemical substances produced in one organ that are released into the bloodstream and affect the function of a target organ. For the target organ to respond to a particular hormone, it must _____.
experience an imbalance that disrupts its normal function modify its plasma membrane to alter the hormone entering the cytoplasm be from the same cell type as the organ that produced the hormone have receptors that recognize and bind the hormone molecule
Have receptors that recognize and bind the hormone molecule