Diversity in Living OrganismsPractice Questions & MCQs

Q1. Which one of the following is the BEST reason for adopting a system of classification of organisms?

• A.It enables convenient study and helps understand the relationships among organisms
• B.It increases the number of species in nature
• C.It is required only for plants and not for animals
• D.It eliminates the need for common names altogether

Answer: A. It enables convenient study and helps understand the relationships among organisms

NCERT fact (biology, chapter 'Diversity in Living Organisms'): Classification enables systematic study of the enormous diversity of life, simplifies identification, and reveals evolutionary and ecological relationships among organisms. It does not affect the number of species in nature, applies to all living things, and complements (rather than replaces) common names. Hence option (a) is correct. Final answer - A) It enables convenient study and helps understand the relationships among organisms.

Q2. Which division includes plants with no well-developed conducting tissue and no true roots, stems or leaves?

• A.Thallophyta (algae)
• B.Bryophyta
• C.Pteridophyta
• D.Gymnospermae

Answer: A. Thallophyta (algae)

What is the textbook's take? Thallophytes (algae) lack a well-differentiated body and have no true roots, stems, leaves or conducting tissues. Bryophytes have a body differentiated into stem- and leaf-like structures but lack vascular tissue; pteridophytes have true roots, stems and leaves with vascular tissue; gymnosperms are seed-bearing vascular plants. Hence option (a) is correct. Pick: A) Thallophyta (algae).

Q3. Which combination of characters distinguishes Aves from Reptilia?

• A.Feathers, pneumatic bones, four-chambered heart and warm-bloodedness
• B.Scales, three-chambered heart and cold-bloodedness
• C.Mammary glands, hair and viviparity
• D.Notochord retained throughout life and absence of jaws

Answer: A. Feathers, pneumatic bones, four-chambered heart and warm-bloodedness

What is the textbook's take? Reptiles are cold-blooded, have scales and a three-chambered heart (crocodile being an exception with an incompletely four-chambered heart). Birds are warm-blooded, have feathers, pneumatic bones for flight and a fully four-chambered heart. Mammary glands belong to mammals, while jaw-less and notochord-retaining bodies fit Agnatha. Option (a) lists the avian set. Pick: A) Feathers, pneumatic bones, four-chambered heart and warm-bloodedness.