1. What is the primary function of secondary metabolites in plants?
a) To support plant growth
b) To protect against herbivores and pathogens
c) To aid in photosynthesis
d) To store energy
Answer: b) To protect against herbivores and pathogens
2. Which of the following is a secondary metabolite found in plants?
a) Glucose
b) Chlorophyll
c) Alkaloids
d) Water
Answer: c) Alkaloids
3. Which secondary metabolite is known for its antibacterial and antifungal properties?
a) Lignin
b) Saponins
c) Tannins
d) Alkaloids
Answer: b) Saponins
4. Terpenoids are important secondary metabolites because they:
a) Aid in photosynthesis
b) Produce essential amino acids
c) Have antimicrobial and insecticidal properties
d) Promote plant growth
Answer: c) Have antimicrobial and insecticidal properties
5. Which class of secondary metabolites is responsible for the coloration of flowers and fruits?
a) Alkaloids
b) Terpenoids
c) Flavonoids
d) Glucosinolate
Answer: c) Flavonoids
6. The role of phenolics in plants is to:
a) Improve soil fertility
b) Provide structural support
c) Protect against UV radiation and pathogens
d) Store energy
Answer: c) Protect against UV radiation and pathogens
7. What is a well-known example of an alkaloid used by humans for medicinal purposes?
a) Caffeine
b) Lignin
c) Chlorophyll
d) Carotenoids
Answer: a) Caffeine
8. Which secondary metabolite is most commonly associated with plant defense mechanisms?
a) Proteins
b) Carbohydrates
c) Secondary metabolites
d) DNA
Answer: c) Secondary metabolites
9. Which secondary metabolite plays a significant role in plant communication, especially in defense responses?
a) Terpenoids
b) Alkaloids
c) Jasmonic acid
d) Glucosinolate
Answer: c) Jasmonic acid
10. The bitter taste of many plants is often due to the presence of:
a) Terpenoids
b) Alkaloids
c) Amino acids
d) Sugars
Answer: b) Alkaloids
11. Which secondary metabolite is important in protecting plants from oxidative stress?
a) Tannins
b) Flavonoids
c) Glucosinolate
d) Phytoalexins
Answer: b) Flavonoids
12. Which secondary metabolites are often used as natural insecticides?
a) Alkaloids
b) Terpenoids
c) Tannins
d) Glucosinolate
Answer: b) Terpenoids
13. What is the function of tannins in plants?
a) Increase water retention
b) Provide structural support
c) Protect against herbivory and pathogens
d) Aid in photosynthesis
Answer: c) Protect against herbivory and pathogens
14. Which secondary metabolites are involved in the bitter taste of plants, deterring herbivores?
a) Alkaloids
b) Carbohydrates
c) Amino acids
d) Nucleotides
Answer: a) Alkaloids
15. Which of the following is a role of flavonoids in plants?
a) Provide energy storage
b) Protect against UV radiation and oxidative stress
c) Help in seed dispersal
d) Aid in water uptake
Answer: b) Protect against UV radiation and oxidative stress
16. The presence of which secondary metabolite in plants helps them repel herbivores by causing toxicity?
a) Terpenoids
b) Alkaloids
c) Glucosinolate
d) Proteins
Answer: b) Alkaloids
17. Which secondary metabolite is primarily involved in plant cell wall strengthening?
a) Lignin
b) Flavonoids
c) Alkaloids
d) Carbohydrates
Answer: a) Lignin
18. Which secondary metabolite is essential for the production of essential oils in aromatic plants?
a) Terpenoids
b) Phenolics
c) Alkaloids
d) Tannins
Answer: a) Terpenoids
19. Glucosinolate compounds are found in which family of plants?
a) Rosaceae
b) Solanaceae
c) Brassicaceae
d) Leguminosae
Answer: c) Brassicaceae
20. Which of the following secondary metabolites plays a role in plant signaling during stress?
a) Phytohormones
b) Flavonoids
c) Alkaloids
d) Terpenoids
Answer: a) Phytohormones
21. Which secondary metabolite group is responsible for the typical aroma of many flowers?
a) Terpenoids
b) Phenolics
c) Glucosinolate
d) Tannins
Answer: a) Terpenoids
22. What is the role of secondary metabolites in plants regarding pathogens?
a) They cause the disease
b) They help in resisting or deterring pathogen attacks
c) They assist in pathogen transmission
d) They allow pathogen entry
Answer: b) They help in resisting or deterring pathogen attacks
23. What is an example of a secondary metabolite with antioxidant properties?
a) Glucosinolate
b) Flavonoids
c) Proteins
d) Sugars
Answer: b) Flavonoids
24. Secondary metabolites that act as toxins to herbivores are known as:
a) Phytoalexins
b) Phytochemicals
c) Antioxidants
d) Glucosinolate
Answer: b) Phytochemicals
25. What is the primary role of alkaloids in plants?
a) Energy storage
b) Enhancing photosynthesis
c) Deterrence of herbivores and pathogens
d) Structural support
Answer: c) Deterrence of herbivores and pathogens
26. Which of the following secondary metabolites contribute to plant color?
a) Alkaloids
b) Tannins
c) Flavonoids
d) Carotenoids
Answer: c) Flavonoids
27. Which secondary metabolite is involved in plant defense against UV light?
a) Terpenoids
b) Flavonoids
c) Glucosinolate
d) Tannins
Answer: b) Flavonoids
28. Which secondary metabolite can serve as a signaling molecule during plant defense responses?
a) Phytoalexins
b) Glucosinolate
c) Jasmonic acid
d) Proteins
Answer: c) Jasmonic acid
29. What is the function of saponins in plants?
a) Provide structural support
b) Act as antioxidants
c) Act as natural insecticides
d) Aid in photosynthesis
Answer: c) Act as natural insecticides
30. Which secondary metabolite is produced in response to pathogen attacks in plants?
a) Phytoalexins
b) Chlorophyll
c) Carbohydrates
d) Amino acids
Answer: a) Phytoalexins
These questions provide a comprehensive understanding of secondary metabolites and their roles in plant defense, growth, and communication.
