Question 1

Which of the following statements best explains the origin of mitochondria in eukaryotic cells according to the endosymbiotic theory?

Accepted Answer

Mitochondria evolved from a symbiotic relationship between an ancestral eukaryotic cell and a bacterial cell capable of respiration.

Question 2

Which of the following is a defining feature of all extant Eukarya?

Accepted Answer

They contain mitochondria, structures homologous to mitochondria, or genetic traces of these structures.

Question 3

Secondary endosymbiosis is best described as:

Accepted Answer

The process of engulfing a green or red algal cell, retaining its chloroplast, and becoming phototrophic.

Question 4

Which of the following supergroups of Eukarya includes organisms that are closely related to plants?

Accepted Answer

Archaeplastida

Question 5

A scientist discovers a unicellular organism with two nuclei of equal size and very reduced mitochondria called mitosomes. Which genus does this organism most likely belong to?

Accepted Answer

Giardia

Question 6

Which of the following diseases is caused by a kinetoplastid organism?

Accepted Answer

African sleeping sickness

Question 7

Euglenids are unique among protists because they:

Accepted Answer

Can switch between phototrophic and chemoorganotrophic lifestyles depending on environmental conditions.

Question 8

Which of the following statements about ciliates is correct?

Accepted Answer

They possess both macronuclei and micronuclei, and exchange micronuclei during conjugation.

Question 9

A marine biologist observes a massive fish kill associated with a red tide. Which group of protists is most likely responsible, and what is the mechanism?

Accepted Answer

Dinoflagellates; they produce neurotoxins that can cause paralytic shellfish poisoning.

Question 10

Which of the following best describes the structure and ecological role of diatoms?

Accepted Answer

They have cell walls made of silica called frustules and are important primary producers in aquatic ecosystems.

Question 11

A protist with threadlike pseudopodia, a shell-like test made of calcium carbonate, and exclusively marine habitat is most likely a:

Accepted Answer

Foraminiferan

Question 12

Which of the following statements about chlorarachniophytes is correct?

Accepted Answer

Their chloroplasts have four membranes, a result of secondary endosymbiosis, and they contain a nucleomorph.

Question 13

Which of the following is a distinguishing feature of haptophytes, particularly coccolithophores?

Accepted Answer

They form intricate mineralized plates (exoskeletons) made of calcite, impacting Earth's carbon cycle.

Question 14

Which of the following best explains the ecological importance of glomeromycota?

Accepted Answer

They form endomycorrhizae, aiding plants in phosphate acquisition and facilitating early plant colonization of land.

Question 15

Which of the following statements about fungal reproduction is correct?

Accepted Answer

Most fungi reproduce asexually by growth and spread of hyphal filaments, asexual spore production, or budding.

Question 16

A patient with a compromised immune system develops a severe infection by a unicellular, obligate parasitic fungus that lacks mitochondria and the citric acid cycle. Which group is most likely responsible?

Accepted Answer

Microsporidia

Question 17

Which of the following is a unique feature of chytridiomycota among fungi?

Accepted Answer

They produce flagellated, motile spores ideal for dispersal in aquatic environments.

Question 18

Which of the following best describes the reproductive process in ascomycota?

Accepted Answer

Two haploid nuclei from different mating types fuse to form a diploid nucleus, which undergoes meiosis to form haploid ascospores.

Question 19

Which of the following is a defining characteristic of basidiomycota?

Accepted Answer

They form haploid basidiospores by meiosis in a structure called a basidium.

Question 20

A researcher isolates a unicellular red alga from a hot, acidic spring. Which genus is this organism most likely to belong to?

Accepted Answer

Cyanidioschyzon

Diversity of Microbial Eukarya: Structure, Phylogeny, and Major Groups

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