Question 1

Which of the following best describes why protists are considered a paraphyletic group?

Accepted Answer

They include some, but not all, descendants of a single common ancestor.

Question 2

Which of the following is a primary ecological role of phytoplanktonic protists?

Accepted Answer

Serving as primary producers at the base of aquatic food webs.

Question 3

A scientist is studying a protist with a ventral feeding groove, reduced mitochondria, and a parasitic lifestyle in the human intestine. To which group does this organism most likely belong?

Accepted Answer

Excavata

Question 4

Which of the following statements about the group Stramenopiles is correct?

Accepted Answer

They include both photosynthetic and non-photosynthetic organisms.

Question 5

Brown algae are classified as protists rather than plants. Which of the following is a key reason for this classification?

Accepted Answer

They are multicellular but do not have true plant tissues.

Question 6

A protist is observed to have long, slender pseudopodia and a shell made of CaCO$_3$. To which group does it most likely belong?

Accepted Answer

Rhizaria

Question 7

Which of the following features is characteristic of Alveolata?

Accepted Answer

Presence of alveoli under the plasma membrane.

Question 8

Oomycetes, a group within Stramenopiles, are best known for which of the following real-world impacts?

Accepted Answer

Destruction of potato crops due to Phytophthora infestans.

Question 9

Which pigment is primarily responsible for the brown color in brown algae?

Accepted Answer

Fucoxanthin

Question 10

A protist is found to be photosynthetic, with a cell wall made of silica dioxide. Which group does it most likely belong to?

Accepted Answer

Diatoms

Question 11

Which of the following best explains why protists are often referred to as a 'group of convenience'?

Accepted Answer

They are grouped together because they do not fit into other eukaryotic kingdoms.

Question 12

Which of the following is a correct match between a protist group and a real-world product derived from it?

Accepted Answer

Brown algae – algin used as a thickener in foods

Question 13

A protist with lobe-like pseudopods that feeds by phagocytosis most likely belongs to which group?

Accepted Answer

Amoebozoa

Question 14

Which of the following is a distinguishing feature of Euglenids within Excavata?

Accepted Answer

Photosynthetic with a flexible pellicle and mitochondria with disc-shaped cristae.

Question 15

Which of the following best describes the evolutionary significance of protists?

Accepted Answer

They are the evolutionary base of all eukaryotes.

Question 16

A protist is observed to have two flagella, one of which is covered in hair-like projections. Which group does it most likely belong to?

Accepted Answer

Stramenopiles

Question 17

Which of the following is a correct statement about the mitochondria in some Excavata?

Accepted Answer

They may have lost mitochondria or have highly modified forms.

Question 18

Which of the following best explains why protists are important in human health and disease?

Accepted Answer

Some protists are parasitic and can cause diseases such as brain-eating amoeba infections.

Question 19

Which of the following methods is NOT typically used to study protist phylogeny?

Accepted Answer

Radioactive dating of fossils

Question 20

A protist is found to have a shell (test) made of CaCO$_3$ and extends slender pseudopodia. Which ecological role does this organism most likely play in marine environments?

Accepted Answer

Contributor to marine sediments and carbon cycling

Protists: Diversity, Classification, and Biological Importance

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