4.1 Introduction to Ecology

Which of the following best describes the primary focus of ecology?

A. Study of individual organisms and their genetics

B. Study of interactions among organisms and their environment

C. Study of cellular structures and functions

D. Study of human-induced environmental changes

Which level of biological organization primarily involves interactions between different species in a specific area?

A. Population

B. Ecosystem

C. Community

D. Biosphere

What is the significance of reproductive isolation in speciation?

A. It prevents gene flow between populations

B. It increases genetic diversity within a population

C. It promotes interbreeding between different species

D. It reduces the adaptation of species to their environment

Which organisms primarily rely on autotrophic nutrition?

A. Fungi

B. Plants

C. Animals

D. Bacteria

What role do detritivores play in an ecosystem?

A. Synthesizing organic compounds

B. Consuming living plant material

C. Breaking down dead organic matter

D. Predating on other animals

a) Define ecology and explain its importance in understanding the natural world. [3]

b) Discuss the different levels of biological organization from individuals to the biosphere, and explain how each level contributes to ecological interactions. [4]

a) Explain what species are and discuss the factors contributing to reproductive isolation. [3]

b) Discuss the importance of reproductive isolation in speciation. [2]

a) Differentiate between autotrophic and heterotrophic nutrition, and provide examples of species with both nutritional methods. [4]

b) Discuss the role of detritivores in obtaining nutrients from detritus and the importance of nutrient availability in ecosystems. [3]

a) Explain the concept of Polymerase Chain Reaction (PCR) and its role in amplifying DNA. [3]

b) Discuss the applications of PCR in medical diagnostics and forensic science. [3]

c) How does PCR contribute to advancements in paleobiology? [2]

a) Describe the principle and procedure of gel electrophoresis. [3]

b) How does gel electrophoresis separate DNA fragments by size? [2]

c) Discuss the applications of gel electrophoresis in DNA profiling and paternity testing. [3]