Q1. Which of the following is not a characteristic feature of algae?
a) Presence of chlorophyll
b) Lack of true roots, stems, and leaves
c) Ability to conduct photosynthesis
d) Ability to move actively in search of food
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Correct Answer: d) Ability to move actively in search of food
Explanation: Algae are photosynthetic organisms that lack true roots, stems, and leaves. They contain chlorophyll and are capable of conducting photosynthesis, but they are not capable of active movement.
Q2. Algae are primarily found in which of the following habitats?
a) Desert
b) Ocean
c) Tundra
d) Mountain
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Correct Answer: b) Ocean
Explanation: Algae are predominantly found in aquatic environments, including oceans, lakes, rivers, and ponds. While some species may inhabit other habitats such as damp soil or tree bark, the majority of algae are aquatic organisms.
Q3. Which of the following pigments is responsible for the green coloration in algae?
a) Chlorophyll a
b) Chlorophyll b
c) Carotenoids
d) Phycobilins
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Correct Answer: a) Chlorophyll a
Explanation: Chlorophyll a is the primary pigment responsible for capturing light energy during photosynthesis in algae. It gives algae their green coloration, similar to plants.
Q4. Which of the following types of algae are commonly referred to as “seaweeds”?
a) Red algae
b) Green algae
c) Brown algae
d) Blue-green algae
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Correct Answer: c) Brown algae
Explanation: Brown algae, also known as Phaeophyta, are commonly referred to as seaweeds due to their large size and brownish coloration. They are found primarily in marine environments.
Q5. Which of the following types of algae are unicellular?
a) Red algae
b) Brown algae
c) Green algae
d) Diatoms
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Correct Answer: d) Diatoms
Explanation: Diatoms are a type of algae that are primarily unicellular, although they may form colonies. They are characterized by their unique silica cell walls and are found in various aquatic habitats.
Q6. Which of the following types of algae are commonly used as food for humans?
a) Red algae
b) Brown algae
c) Green algae
d) Blue-green algae
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Correct Answer: c) Green algae
Explanation: Some species of green algae, such as Chlorella and Spirulina, are commonly used as food supplements for humans due to their high nutritional content. They are rich in proteins, vitamins, and minerals.
Q7. Which of the following types of algae are capable of fixing atmospheric nitrogen?
a) Red algae
b) Brown algae
c) Green algae
d) Blue-green algae
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Correct Answer: d) Blue-green algae
Explanation: Blue-green algae, also known as cyanobacteria, are capable of nitrogen fixation, a process by which they convert atmospheric nitrogen into a form that can be utilized by plants and other organisms.
Q8. Which of the following types of algae are commonly found in symbiotic relationships with corals?
a) Red algae
b) Brown algae
c) Green algae
d) Dinoflagellates
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Correct Answer: a) Red algae
Explanation: Certain species of red algae form symbiotic relationships with coral animals, contributing to the formation of coral reefs. These algae provide nutrients to the corals and receive protection in return.
Q9. Which of the following types of algae are responsible for the phenomenon known as “red tides”?
a) Red algae
b) Brown algae
c) Green algae
d) Dinoflagellates
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Correct Answer: d) Dinoflagellates
Explanation: Dinoflagellates are a type of algae that can undergo rapid population growth, leading to the formation of dense blooms known as “red tides.” These blooms can have detrimental effects on marine ecosystems and human health.
Q10. Which of the following types of algae are commonly used in the production of agar?
a) Red algae
b) Brown algae
c) Green algae
d) Blue-green algae
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Correct Answer: a) Red algae
Explanation: Agar, a gelatinous substance used in various applications such as microbiology and food industry, is derived from certain species of red algae, particularly from the genera Gelidium and Gracilaria.