The concept of ecosystem services refers to the benefits humans obtain from ecosystems. Which of the following is classified as a REGULATING service?
Answer: B
Regulating services include processes like climate regulation, pollination, disease control, and water purification that maintain ecosystem functions benefiting humans, distinct from provisioning, cultural, or supporting services.
Q.102Hard
Which succession model proposes that early colonizing species modify the environment to facilitate or inhibit later species establishment?
Answer: B
The facilitation model (Connell & Slatyer) proposes that pioneer species modify environmental conditions to make them more suitable for subsequent species, gradually changing the ecosystem toward climax community.
Q.103Hard
In the context of India's monsoon-dependent ecosystems, which adaptive strategy is most evident in deciduous forest species?
Answer: B
Deciduous trees in Indian dry and moist deciduous forests shed leaves during the dry season (March-May) as an adaptation to seasonal water scarcity, reducing transpirational water loss while maintaining survival.
Q.104Hard
In India's Western Ghats, the introduction of invasive species like Lantana camara has led to reduced native plant diversity and altered nutrient cycling. This phenomenon best demonstrates which ecological principle?
Answer: B
Lantana camara outcompetes native vegetation through superior resource acquisition and allelopathy, leading to competitive exclusion. This reduces niche availability for native species, fundamentally altering community structure and ecosystem functions like nutrient cycling.
Q.105Hard
In the context of gene therapy, what does 'ex vivo' gene therapy mean?
Answer: A
Ex vivo gene therapy involves isolating cells from the patient, modifying them genetically outside the body, and then reintroducing them, reducing immune reactions.
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Q.106Hard
Which of the following statements about RNAi (RNA interference) is correct?
Answer: B
RNAi uses small interfering RNAs (siRNA) or short hairpin RNA (shRNA) to target and degrade specific mRNA molecules, leading to gene silencing.
Q.107Hard
What is a chimeric gene in the context of genetic engineering?
Answer: B
Chimeric genes combine regulatory sequences from one organism with coding sequences from another, creating novel genetic constructs for transgenic organism development.
Q.108Hard
In the year 2023-24, which Indian institute developed the CRISPR-based diagnostic kit for disease detection?
Answer: B
CSIR-Institute of Genomics and Integrative Biology (IGIB) has been at the forefront of developing CRISPR-based diagnostic tools for various diseases in India.
Q.109Hard
What is the primary concern regarding the large-scale cultivation of Bt crops in India?
Answer: B
Major concerns include the development of resistance in target insects, impacts on non-target beneficial organisms, and long-term ecological effects of Bt crop cultivation.
Q.110Hard
In gene editing using base editors, what advantage do they offer over traditional CRISPR-Cas9?
Answer: A
Base editors (BEs) convert one DNA base to another without creating double-strand breaks, reducing off-target effects and cellular damage compared to standard CRISPR-Cas9.
Q.111Hard
In the context of organ transplantation, what is the potential application of xenotransplantation biotechnology?
Answer: A
Xenotransplantation involves genetically modifying animal organs (usually pig organs) to reduce immune rejection, potentially addressing the chronic shortage of human donor organs.
Q.112Hard
What is the mechanism by which TALEN (Transcription Activator-Like Effector Nuclease) technology achieves site-specific gene editing?
Answer: B
TALENs are proteins from Xanthomonas bacteria that recognize specific DNA sequences with modular repeat domains and direct FokI endonuclease for precise DNA cleavage.
