Chapter Exam

Chapter 6: Principles of Ecology — Online MCQ Test

Q: The study of reciprocal relationship between every single species and its environment is called:

Answer: B. Autecology — Autecology is the study of the ecology of an individual species or its population, whereas synecology is the study of communities.

Q: Epiphytes like Vanda possess a special multi-layered hygroscopic epidermis to absorb moisture from the atmosphere. What is this tissue called?

Answer: B. Velamen — Velamen is a specialized hygroscopic tissue found in the aerial roots of epiphytic orchids like Vanda that helps in absorbing atmospheric moisture.

Q: Identify the correct pair of plants that show 'Cladode' (a modified stem of limited growth) and 'Phylloclade' (green, flat stem of unlimited growth) respectively.

Answer: B. Asparagus and Opuntia — In Asparagus, the stem is modified into cladodes of limited growth, while Opuntia possesses a phylloclade which is a succulent green stem with unlimited growth.

Q: Plants that grow specifically in the narrow crevices of rocks are referred to as:

Answer: B. Chasmophytes — Lithophytes grow on the surface of rocks, whereas plants that specifically grow inside rock crevices where small amounts of organic soil accumulate are termed Chasmophytes.

BOTANY · CLASS 12th · Tamil Nadu State Board

Practice Chapter 6: Principles of Ecology with a free chapter-wise online MCQ test for Tamil Nadu State Board CLASS 12th BOTANY. This chapter covers: Exploring ecological concepts this chapter examines autecology synecology and ecological adaptations in plants. Students study environmental factors like temperature light water an.... AI-generated questions from basic to board-exam level, with instant results and explanations.

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Chapter 6: Principles of Ecology — Important Questions & Answers (FAQ)

Frequently asked questions from Tamil Nadu State Board CLASS 12th BOTANY — Chapter 6: Principles of Ecology, with answers and explanations. These are sample questions; the exam has its own separate question set.

The study of reciprocal relationship between every single species and its environment is called:

A. Synecology
B. Autecology ✓
C. Palaeoecology
D. Genecology

Answer: B. Autecology
Autecology is the study of the ecology of an individual species or its population, whereas synecology is the study of communities.

Epiphytes like Vanda possess a special multi-layered hygroscopic epidermis to absorb moisture from the atmosphere. What is this tissue called?

A. Pneumatophore
B. Velamen ✓
C. Parenchyma
D. Aerenchyma

Answer: B. Velamen
Velamen is a specialized hygroscopic tissue found in the aerial roots of epiphytic orchids like Vanda that helps in absorbing atmospheric moisture.

Identify the correct pair of plants that show 'Cladode' (a modified stem of limited growth) and 'Phylloclade' (green, flat stem of unlimited growth) respectively.

A. Opuntia and Casuarina
B. Asparagus and Opuntia ✓
C. Ruscus and Euphorbia
D. Euphorbia and Asparagus

Answer: B. Asparagus and Opuntia
In Asparagus, the stem is modified into cladodes of limited growth, while Opuntia possesses a phylloclade which is a succulent green stem with unlimited growth.

An orchid seed is extremely small and light, containing almost no food reserves. During germination, it must establish an association with a fungus (Mycorrhiza) to obtain nutrients. This association represents which type of interaction?

A. Commensalism, because only the orchid benefits
B. Mutualism, because both orchid and fungus exchange nutrients and sustain growth ✓
C. Parasitism, because the orchid robs the fungus of carbon sources
D. Amensalism, because the fungus is harmed by the orchid's growth

Answer: B. Mutualism, because both orchid and fungus exchange nutrients and sustain growth
Mycorrhizal association is a classic example of mutualism where both organisms benefit; the plant gets inorganic nutrients and water while the fungus gets organic food.

Plants that grow specifically in the narrow crevices of rocks are referred to as:

A. Lithophytes
B. Chasmophytes ✓
C. Psammophytes
D. Calcifuges

Answer: B. Chasmophytes
Lithophytes grow on the surface of rocks, whereas plants that specifically grow inside rock crevices where small amounts of organic soil accumulate are termed Chasmophytes.

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