MasteringBiology #1 – Flashcards
10 test answers
Unlock all answers in this set
Unlock answers 10question
Which molecule did Carl Woese study to produce his tree of life?
answer
Ribosomal RNA
Unlock the answer
question
What is lateral gene transfer?
answer
Physical transfer of a gene from a species in one lineage to a species in another lineage.
Unlock the answer
question
Classify each statement or picture as applying to gram-positive bacteria, gram-negative bacteria, or both.
answer
Gram-positive bacteria: -appear purple after Gram staining -have a thick peptidoglycan layer -alcohol rinse does not remove crystal violet
Unlock the answer
question
Classify each statement or picture as applying to gram-positive bacteria, gram-negative bacteria, or both.
answer
Gram-negative bacteria: -appear pink after Gram staining -have thin peptidoglycan layer -alcohol rinse easily removes crystal violet -have an outer membrane as part of their cell wall structure
Unlock the answer
question
Label the diagram below to show the relationship between nutritional modes of bacteria.
answer
a) autotrophs b) heterotrophs c) chemoautotrophs d) photoautotrophs e) photoheterotrophs f) chemoheterotrophs g) phototrophs h) chemotrophs
Unlock the answer
question
Azotobacter is a genus of bacteria that live in soil and have the following characteristics: They are bacilli. They are gram-negative. They are obligate aerobes. They can fix nitrogen. (Unlike some other nitrogen-fixing bacteria, which associate with the roots of plants, Azotobacter species are free-living.) Select the four statements that are true for bacteria in the genus Azotobacter.
answer
They can convert atmospheric nitrogen to ammonia. They have a relatively thin layer of peptidoglycan in their cell wall. They use O2 for cellular respiration. They are shaped like rods.
Unlock the answer