Question 1

Which structural feature is unique to Gram-negative bacteria and contributes to their increased resistance to antibiotics compared to Gram-positive bacteria?

Accepted Answer

An outer membrane containing lipopolysaccharides

Question 2

A scientist discovers a prokaryote living in a hot spring with a cell wall lacking peptidoglycan and membrane lipids containing branched hydrocarbons. To which domain does this organism most likely belong?

Accepted Answer

Archaea

Question 3

Which process allows a bacterium to acquire new genetic material from its environment, potentially leading to antibiotic resistance?

Accepted Answer

Transformation

Question 4

A prokaryote that uses light as an energy source and CO$$_2 as a $$carbon source is classified as a:

Accepted Answer

Photoautotroph

Question 5

Which of the following best explains why nitrogen-fixing bacteria are crucial for ecosystems?

Accepted Answer

They convert atmospheric nitrogen ($$N_2) $$into ammonia ($$NH_3$$), making nitrogen available to plants.

Question 6

Which of the following statements about endosymbiosis is correct?

Accepted Answer

Plastids in Archaeplastida originated from primary endosymbiosis of a photosynthetic prokaryote.

Question 7

A protist that can switch between photosynthesis and ingesting food particles depending on environmental conditions is best described as a:

Accepted Answer

Mixotroph

Question 8

Which major supergroup of eukaryotes includes the closest relatives of land plants?

Accepted Answer

Archaeplastida

Question 9

A patient is infected with a bacterium that is resistant to penicillin. Laboratory tests reveal the bacterium has a thin peptidoglycan layer and an outer membrane. Which type of bacterium is most likely responsible?

Accepted Answer

Gram-negative bacterium

Question 10

Which of the following best describes the role of prokaryotes as decomposers in the environment?

Accepted Answer

They break down dead organic matter, recycling nutrients back into the ecosystem.

Question 11

Which protist clade is characterized by the presence of modified mitochondria and includes organisms such as diplomonads?

Accepted Answer

Excavata

Question 12

A researcher observes a protist with a life cycle that alternates between multicellular haploid and diploid stages. This is an example of:

Accepted Answer

Alternation of generations

Question 13

Which metabolic strategy would you expect to find in a bacterium living deep underground, using inorganic chemicals as an energy source and $$CO_2 as a $$carbon source?

Accepted Answer

Chemoautotrophy

Question 14

Which of the following is a key difference between Bacteria and Archaea?

Accepted Answer

Archaea have membrane lipids with branched hydrocarbons, while Bacteria do not

Question 15

Which process involves the transfer of genetic material between bacteria via a virus?

Accepted Answer

Transduction

Question 16

Which group within the SAR supergroup includes important photosynthetic organisms that form the base of many aquatic food webs?

Accepted Answer

Diatoms

Question 17

A hospital-acquired infection is caused by a bacterium that can survive in the presence of oxygen but also grow without it. This bacterium is best described as:

Accepted Answer

Facultative anaerobe

Question 18

Which of the following best describes secondary endosymbiosis?

Accepted Answer

A eukaryote engulfs another eukaryote that already contains a plastid

Question 19

Which of the following is NOT a typical ecological role of prokaryotes?

Accepted Answer

Producer of multicellular embryos

Question 20

Which supergroup includes both animals and fungi, as well as amoebozoans?

Accepted Answer

Unikonta

Study Notes: Bacteria, Archaea, and Protists (Chapters 27 & 28)

Study Guide - Practice Questions

Study Guide - Flashcards