#1
Which of the following is a characteristic feature of protists?
They have a nucleus.
ExplanationPresence of a nucleus is a defining characteristic of protists.
#2
Which protist group includes organisms responsible for causing malaria?
Apicomplexans
ExplanationApicomplexans, such as Plasmodium species, are responsible for causing malaria.
#3
Which of the following is not a characteristic of protists?
They are all parasites.
ExplanationNot all protists are parasites; they exhibit diverse ecological roles.
#4
Which protist group includes organisms that possess both plant-like and animal-like characteristics?
Euglenoids
ExplanationEuglenoids exhibit characteristics of both plants and animals, such as photosynthesis and movement.
#5
Which protist group is characterized by having thread-like pseudopodia?
Foraminiferans
ExplanationForaminiferans exhibit thread-like pseudopodia for locomotion and feeding.
#6
Which structure in some protists functions similarly to the contractile vacuole in amoebas?
Contractile vacuole
ExplanationContractile vacuole serves as an osmoregulatory organelle in some protists.
#7
What is the defining characteristic of the phylum Bacillariophyta?
Presence of silica shells
ExplanationBacillariophyta are characterized by their silica shell, known as frustules.
#8
Which of the following is not a function of the pellicle in some protists?
Nutrient absorption
ExplanationThe pellicle provides structural support and protection, but it is not involved in nutrient absorption.
#9
What is the primary ecological role of protists in aquatic ecosystems?
Photosynthesis
ExplanationProtists play a crucial role in aquatic ecosystems by performing photosynthesis.
#10
Which protist group includes organisms responsible for red tides?
Dinoflagellates
ExplanationDinoflagellates can cause red tides, harmful algal blooms that can have detrimental effects on marine ecosystems.
#11
Which evolutionary event led to the diversification of eukaryotes and the emergence of protists?
Endosymbiosis of a prokaryote by a eukaryote
ExplanationEndosymbiosis of prokaryotic cells led to the evolution of eukaryotes, including protists.
#12
Which of the following protist groups includes organisms capable of producing bioluminescence?
Dinoflagellates
ExplanationDinoflagellates are known to produce bioluminescence, often observed as 'phosphorescence' in oceans.
#13
Which protist group includes organisms that form calcium carbonate shells?
Radiolarians
ExplanationRadiolarians are known for their intricate calcium carbonate skeletons, contributing to oceanic sediments.
#14
Which protist group includes organisms that are important components of marine plankton and contribute significantly to carbon fixation?
Diatoms
ExplanationDiatoms are a major component of marine plankton and play a crucial role in carbon fixation through photosynthesis.
#15
Which protist group includes organisms that form intricate mineral skeletons and are important contributors to deep-sea sediments?
Radiolarians
ExplanationRadiolarians possess intricate mineral skeletons and contribute significantly to deep-sea sediments.