Q151. The Covid-19 vaccines produced by Pfizer- BioNTech and Moderna are based on which novel vaccine technology?
Health, Environment and Agriculture: RAS Prelims MCQs
662 RAS Prelims practice MCQs on health, environment and agriculture are on this page, in 4 chapters. They cover human health, food, nutrition and public health programmes, environmental and ecological changes and impact assessment, biodiversity and conservation of natural resources, and agriculture, horticulture, forestry and animal husbandry in Rajasthan. Each question has an answer and an explanation.
Practice questions based on the RPSC RAS Prelims syllabus. They follow the exam pattern but are not past-paper questions.
Showing 151–160 of 662 questions
Browse Health, Environment and Agriculture chapters
Q152. Which of the following best defines an ecosystem?
Explanation
An ecosystem encompasses all living organisms in a given area interacting with their physical, non-living environment like soil, water, and air. This complex system functions as a unit through energy flows and nutrient cycling. Both biotic and abiotic factors are inextricably linked, ensuring the continuous survival and stability of the entire biological community within its surroundings.
Q153. Which among the following is not classified as an abiotic component of an ecosystem?
Explanation
Abiotic components are the non-living chemical and physical parts of the environment that affect living organisms and the functioning of ecosystems. Examples include temperature, sunlight, and minerals. In contrast, organisms that break down organic matter are biological entities. These life forms belong to the biotic category, playing a vital role in recycling nutrients by consuming dead plants and animals.
Q154. What is an ecotone in the context of ecosystems?
Explanation
An ecotone serves as a boundary or transition area where two different biological communities meet and integrate. This zone often contains species from both adjacent ecosystems and may even support unique organisms not found in either. Because it acts as a bridge between diverse habitats, it usually exhibits high biodiversity and distinct environmental conditions compared to the surrounding major biomes.
Q155. Which of the following represents a functional aspect of an ecosystem?
Explanation
Functional aspects of an ecosystem describe how the system operates and sustains itself over time. These include processes like productivity, decomposition, and the movement of essential elements through various environmental reservoirs. The circulation of minerals and chemical elements between the biotic and abiotic components ensures that life-sustaining resources remain available for all organisms within the stable biological community.
Q156. Identify the incorrect statement regarding the types of ecosystems.
Explanation
Ecosystems are categorized based on their origin and habitat. Natural ecosystems, such as forests or estuaries, develop without human interference. However, agricultural lands used for growing food are artificial systems because they are created and managed by humans. These man-made terrestrial environments require constant intervention, such as irrigation and fertilization, to maintain their specific biological structure and productivity.
Q157. In an ecosystem, which organisms are primarily responsible for converting complex organic matter into simple inorganic substances?
Explanation
Certain organisms specialize in breaking down complex organic remains of dead plants and animals into simpler inorganic molecules. These biological recyclers, often found in soil or water, perform the critical process of decomposition. By releasing enzymes to digest waste externally and then absorbing the nutrients, they return vital minerals to the environment, allowing producers to reuse them for growth.
Q158. The rate at which organic matter is created by producers in an ecosystem is known as:
Explanation
Primary productivity represents the speed at which autotrophs like plants produce biomass through photosynthesis. The total amount of chemical energy or organic matter generated per unit area over a specific period is defined as the gross value. This total production includes the energy that the plants themselves will eventually use for their own respiration and basic metabolic maintenance needs.
Q159. Given below are two statements, one is labelled as Assertion (A) and the other as Reason (R):
Assertion (A): Energy flow in an ecosystem is always strictly unidirectional.
Reason (R): Energy captured by autotrophs does not revert back to solar input.
Assertion (A): Energy flow in an ecosystem is always strictly unidirectional.
Reason (R): Energy captured by autotrophs does not revert back to solar input.
Explanation
Energy enters an ecosystem primarily through sunlight, which is captured by plants during photosynthesis. This energy then moves through successive trophic levels as organisms consume one another. Since thermodynamic laws dictate that energy is lost as heat at every transfer, it cannot return to the sun. Therefore, the movement of energy remains a one-way path from producers to top consumers.
Q160. Through which biological process do plants release water vapor into the atmosphere?
Explanation
Living vegetation plays a significant role in the local and global climate by moving water from the soil back into the air. Through small openings in their leaves, plants release moisture that has been absorbed by their roots. This biological process not only helps cool the plant but also contributes significantly to the total amount of humidity in the surrounding atmosphere.Answer key for these questions
| Q | Correct answer |
|---|---|
| 151 | (b) Messenger RNA (mRNA) |
| 152 | (b) Interacting organisms and their physical environment |
| 153 | (a) Decomposers |
| 154 | (c) A zone of transition between diverse ecosystems |
| 155 | (d) Nutrient cycling |
| 156 | (c) Crop fields are considered natural terrestrial ecosystems. |
| 157 | (b) Saprotrophs |
| 158 | (d) Gross primary productivity |
| 159 | (a) Both A and R are true and R is the correct explanation of A. |
| 160 | (d) Transpiration |
Key facts from Health, Environment and Agriculture
- The RPSC General Science syllabus includes human health and nutrition, environmental change, biodiversity and the agriculture of Rajasthan.
- Health questions pair a deficiency or a programme with its cause or target, for example iron with anaemia.
- Environment questions cover ecosystems, pollutants, laws and treaties, including carbon markets.
- Rajasthan agriculture questions deal with dryland farming, crops of the arid zones and the State’s agro-climatic zones.
- Science and technology, policies and defence are on the Science and Technology page.
Frequently asked questions
How many RAS Prelims practice MCQs are there on Health, Environment and Agriculture?
This page has 662 practice MCQs on Health, Environment and Agriculture. Each has the correct answer, and most have an explanation.
Which chapters does this set cover?
Four chapters: human health, food, nutrition and public health programmes; environmental and ecological changes and their impact assessment; biodiversity, conservation of natural resources and sustainable development; and agriculture, horticulture, forestry and animal husbandry in Rajasthan.
Are health, environment and agriculture part of the RAS Prelims syllabus?
Yes. The General Knowledge and General Science paper includes human health, nutrition, environment, biodiversity and the agriculture sector of Rajasthan, so these topics can be asked every year.
How can I revise this part of the syllabus?
Make short lists of deficiency diseases, pollutants, laws and treaties, and Rajasthan crops and zones. Attempt each chapter, read the explanations of the misses and revisit the lists after a few days.