Question 1

Which of the following statements best explains why viruses are not considered living organisms?

Accepted Answer

They can only reproduce inside a host cell and lack independent metabolism.

Question 2

A scientist discovers a microorganism that thrives in hot springs at 70°C, has ether-linked membrane lipids, and lacks peptidoglycan in its cell wall. To which group does this organism most likely belong?

Accepted Answer

Archaea

Question 3

Which of the following best describes the process of binary fission in prokaryotes?

Accepted Answer

A parent cell divides into two genetically identical daughter cells after DNA replication and septum formation.

Question 4

Which of the following equations correctly represents the oxygenic photosynthesis carried out by cyanobacteria?

Accepted Answer

$$12\ \mathrm{H}_2\mathrm{O} + 6\ \mathrm{CO}_2 \rightarrow \mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6\ \mathrm{H}_2\mathrm{O} + 6\ \mathrm{O}_2$$

Question 5

Which of the following is a unique feature of Mycobacterium that contributes to its resistance to desiccation and many antibiotics?

Accepted Answer

Presence of a waxy cell wall rich in mycolic acids

Question 6

During the lytic cycle of a bacteriophage, which step immediately follows biosynthesis?

Accepted Answer

Maturation (Assembly)

Question 7

Which of the following best describes the difference in ploidy during mitosis and meiosis in eukaryotic cells?

Accepted Answer

Mitosis: $$2n \rightarrow 2n$$; Meiosis: $$2n \rightarrow n$$

Question 8

A researcher is studying a unicellular eukaryote that moves using cilia and has membrane-bound sacs (alveoli) beneath its cell membrane. To which group does this organism most likely belong?

Accepted Answer

Alveolates

Question 9

Which of the following statements about endospore formation is correct?

Accepted Answer

Endospores are produced by Clostridium and Bacillus and allow survival in harsh conditions.

Question 10

Which of the following best describes the alternation of generations in algae?

Accepted Answer

A life cycle alternating between haploid gametophyte and diploid sporophyte stages

Question 11

Which of the following statements about viral envelopes is correct?

Accepted Answer

The envelope is derived from the host cell membrane during viral release.

Question 12

A patient is diagnosed with a disease caused by a prion. Which of the following best describes the infectious agent?

Accepted Answer

A misfolded protein lacking nucleic acids

Question 13

Which of the following best explains why viruses cannot be cultured on standard nutrient agar plates?

Accepted Answer

Viruses require living host cells for replication.

Question 14

Which of the following genome types is most similar to the genetic material of eukaryotic host cells and can be directly translated by host ribosomes?

Accepted Answer

+ssRNA

Question 15

Which of the following is a function of nitrifying bacteria (Alphaproteobacteria) in the nitrogen cycle?

Accepted Answer

Converting ammonia to nitrite and nitrite to nitrate

Question 16

Which of the following best describes the process of multiple fission (schizogony) in protozoans?

Accepted Answer

A single cell divides into many daughter cells simultaneously.

Question 17

Which of the following statements about viroids is correct?

Accepted Answer

Viroids are infectious RNA molecules that lack a protein coat and typically infect plants.

Question 18

Which of the following steps occurs first in the lytic cycle of a bacteriophage?

Accepted Answer

Attachment to the host cell

Question 19

Which of the following best describes the main difference between prokaryotic and eukaryotic cells?

Accepted Answer

Prokaryotes lack membrane-bound organelles and have circular DNA, while eukaryotes have membrane-bound organelles and linear DNA.

Question 20

A laboratory is preparing to culture influenza virus for vaccine production. Which method is most appropriate for this purpose?

Accepted Answer

Inoculation of embryonated chicken eggs

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