Question 1

Which of the following provides the strongest evidence supporting the endosymbiotic theory for the origin of mitochondria and chloroplasts in eukaryotic cells?

Accepted Answer

Both organelles contain their own DNA, which closely resembles prokaryotic DNA.

Question 2

A scientist discovers a unicellular organism with two nuclei, multiple flagella, and modified mitochondria called mitosomes. The organism is most likely:

Accepted Answer

A diplomonad, such as Giardia intestinalis

Question 3

Which of the following best explains why 'Kingdom Protista' is considered paraphyletic?

Accepted Answer

It includes organisms that do not share a single common ancestor exclusive to them.

Question 4

A patient presents with recurring fever and chills after traveling to a tropical region. Blood tests reveal infection by a spore-forming parasite with an apical complex. Which vector most likely transmitted this disease?

Accepted Answer

Anopheles mosquito

Question 5

Which of the following protists is responsible for 'red tides' that can cause massive fish kills and respiratory issues in humans?

Accepted Answer

Dinoflagellates

Question 6

A protist is observed to have a flexible pellicle, a pocket at one end with one or two flagella, and can switch from autotrophic to heterotrophic nutrition in the dark. This organism is most likely:

Accepted Answer

A euglenoid, such as Euglena

Question 7

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

Accepted Answer

A diploid sporophyte undergoes meiosis to produce haploid spores, which grow into haploid gametophytes.

Question 8

Which of the following is a correct match between a protist group and a disease it causes?

Accepted Answer

Kinetoplastids – Chagas disease

Question 9

A protist with a glassy exoskeleton of silica, radial symmetry, and threadlike pseudopodia extending through small openings is most likely a:

Accepted Answer

Radiolarian

Question 10

Which of the following statements about diatoms is correct?

Accepted Answer

They have double shells made of opaline silica and are important components of phytoplankton.

Question 11

A protist is found to have no centrioles or flagella, reproduces by alternation of generations, and is used to wrap sushi. This organism is most likely:

Accepted Answer

Red algae (Porphyra)

Question 12

Which of the following best describes the nutritional strategies found among protists?

Accepted Answer

They include phototrophs, heterotrophs (osmotrophs and phagotrophs), and mixotrophs.

Question 13

Which of the following protists is most likely to be responsible for the formation of limestone deposits such as the White Cliffs of Dover?

Accepted Answer

Foraminiferans

Question 14

A researcher observes a protist that forms a multinucleate, moving mass of cytoplasm during its feeding phase and forms a sporangium under adverse conditions. This organism is most likely a:

Accepted Answer

Plasmodial slime mold

Question 15

Which of the following is a unique feature of kinetoplastids that helps them evade the host immune system?

Accepted Answer

They frequently change their surface proteins in a 'bait-and-switch' defense.

Question 16

Which of the following best describes conjugation in Paramecium?

Accepted Answer

It involves the exchange of micronuclei between two individuals.

Question 17

A protist is found in the gut of termites and helps digest cellulose. It has undulating membranes, flagella, and reduced mitochondria called hydrogenosomes. This organism is most likely:

Accepted Answer

A parabasalid, such as Trichonympha

Question 18

Which of the following protists is most likely to cause amebic dysentery in humans, and how is it transmitted?

Accepted Answer

Entamoeba histolytica; spread via contaminated food, water, or eating utensils

Question 19

Which of the following is a correct statement about the life cycle of Ulva (sea lettuce)?

Accepted Answer

It exhibits alternation of generations, with both multicellular haploid and diploid stages.

Question 20

A protist is observed to have biflagellated cells, is photosynthetic, and can form protective cysts under harsh conditions. It is most likely:

Accepted Answer

Golden alga

Protists: Diversity, Structure, and Evolutionary Significance

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