1. Which one among the following States of India experienced the highest

Which one among the following States of India experienced the highest fall in population growth rate during 2001-2011 in relation to the previous decade?

Andhra Pradesh
Maharashtra
Tamil Nadu
Madhya Pradesh
This question was previously asked in
UPSC Geoscientist – 2023
The correct option is B) Maharashtra. Among the given states, Maharashtra experienced the highest fall in decadal population growth rate between 2001-2011 compared to the 1991-2001 decade.
– The question asks for the state with the *highest fall* in population growth rate, not the lowest growth rate.
– Population growth rates fluctuate, and various socio-economic factors influence them.
– Comparing the decadal growth rates for the given options:
– Andhra Pradesh: 14.59% (1991-2001) to 10.98% (2001-2011) – Fall of 3.61%
– Maharashtra: 22.73% (1991-2001) to 15.99% (2001-2011) – Fall of 6.74%
– Tamil Nadu: 11.72% (1991-2001) to 15.60% (2001-2011) – Increase of 3.88%
– Madhya Pradesh: 24.26% (1991-2001) to 20.30% (2001-2011) – Fall of 3.96%
– Maharashtra shows the largest fall in percentage points among the given options.
The Census of India data provides detailed population statistics including decadal growth rates for all states and Union Territories. Factors contributing to changes in population growth rates include fertility rates, migration, awareness campaigns, and socio-economic development. Southern states like Tamil Nadu and Kerala generally have lower growth rates but may not have experienced the *largest fall* in the specific decade compared to states with initially higher growth rates.

2. What is ‘pyrophilous organism’?

What is ‘pyrophilous organism’?

Fresh grass growing after ground fire
Fungi growing in soils of burnt terrains
Seeds germinating after clear felling of forest
Organisms with capacity to regenerate the tail after it was lost due to damage
This question was previously asked in
UPSC Geoscientist – 2023
The correct answer is Fungi growing in soils of burnt terrains.
‘Pyrophilous’ means ‘fire-loving’. Pyrophilous organisms are those that are either dependent on fire for part of their life cycle or thrive in environments recently affected by fire. Fungi that specifically colonize or grow best on burnt organic matter or in fire-affected soil are classic examples of pyrophilous organisms.
While fresh grass might grow rapidly after a fire (due to nutrient release and reduced competition), the term pyrophilous specifically describes organisms that are *favored* *by* the fire itself. Some seeds are pyrophilous because heat from fire breaks dormancy. Option D describes regeneration after injury, not fire dependency.

3. Which one of the following is a gravity transported soil?

Which one of the following is a gravity transported soil?

Alluvial
Eolian
Colluvial
Glacial
This question was previously asked in
UPSC Geoscientist – 2023
The correct answer is Colluvial.
Colluvial soil is soil that has been transported and deposited by gravity. This occurs on slopes where material moves downwards due to processes like creep, landslides, rockfalls, and sheetwash.
Alluvial soil is transported by flowing water (rivers, streams). Eolian soil is transported by wind (e.g., loess, sand dunes). Glacial soil is transported by glaciers (e.g., till, moraines).

4. What is ‘duff’?

What is ‘duff’?

Partially decomposed litter
Weathered rock
Muddy puddle
Carcass of a dead animal
This question was previously asked in
UPSC Geoscientist – 2023
The correct answer is Partially decomposed litter.
‘Duff’ is an ecological term referring to the layer of organic matter on the floor of a forest or wooded area, consisting of fallen leaves, twigs, and other plant debris in various stages of decomposition. It is the layer above the mineral soil but below the fresh litter.
Duff is also known as the O horizon (organic layer) in soil profiles, specifically the Oi (slightly decomposed) and Oe (moderately decomposed) sub-horizons, although the term ‘duff’ sometimes specifically refers to the Oel and Ofh layers in certain classification systems. It plays a significant role in forest nutrient cycling and fire behavior.

5. Which one of the following organisms can live both in air (outside wat

Which one of the following organisms can live both in air (outside water) and in water?

Xerocole
Mesocole
Secondary hydrocole
Mesophyte
This question was previously asked in
UPSC Geoscientist – 2023
Based on the options provided and the process of elimination, ‘Secondary hydrocole’ is the most plausible answer, although the term is not standardly defined in this context.
The question describes an organism that can live both in terrestrial (“in air outside water”) and aquatic (“in water”) environments, which is characteristic of an amphibious lifestyle. Of the given options, ‘Xerocole’ refers to dry-adapted animals, ‘Mesocole’ to moderate-habitat animals, and ‘Mesophyte’ to moderate-moisture plants. None of these clearly describe an amphibious organism. While the term ‘Secondary hydrocole’ is not universally used to mean amphibious, in some specific ecological classifications, it might relate to organisms that have returned to aquatic life from terrestrial ancestors and retain some ability to function or spend time on land, or require both habitats for their life cycle (like amphibians). Given the other options are clearly incorrect, C is the intended answer despite potential ambiguity in terminology.
Amphibians are the classic example of animals that live in both water and on land, typically spending larval stages in water and adult stages on land. Other animals like crocodiles, some turtles, and many insects with aquatic larvae and terrestrial adults also fit this description.

6. What is ecological amplitude?

What is ecological amplitude?

The range of demands and consequent range of tolerance of a species to the fluctuations in environmental conditions
The range of tolerance of a species in constant environmental conditions
The range of demands of a species in constant environmental conditions
The range of ecological conditions found in a biome
This question was previously asked in
UPSC Geoscientist – 2023
The correct answer is The range of demands and consequent range of tolerance of a species to the fluctuations in environmental conditions.
Ecological amplitude refers to the range of environmental conditions (such as temperature, moisture, salinity, pH, etc.) within which a species can survive, grow, and reproduce. It is determined by the physiological tolerance limits of the species to fluctuations in these conditions and its specific resource requirements (demands).
Species with a wide ecological amplitude are called eurytopic and can inhabit diverse environments. Species with a narrow ecological amplitude are called stenotopic and are restricted to specific environmental conditions. Options B and C are incomplete as they focus only on tolerance or demands, not the combined range of conditions. Option D describes a characteristic of a biome, not a species’ ecological amplitude.

7. In deep ponds and lakes, which one of the following vertical zones rec

In deep ponds and lakes, which one of the following vertical zones receives least light penetration?

Surface
Littoral zone
Limnetic zone
Profundal zone
This question was previously asked in
UPSC Geoscientist – 2023
The correct answer is Profundal zone.
In deep ponds and lakes, the water column is divided into different zones based on light penetration. The Profundal zone is the deep-water zone beneath the Limnetic zone, where light penetration is insufficient for photosynthesis. It is often dark and characterized by decomposition.
The Surface (Epilimnion) and Limnetic zones are well-lit areas where photosynthesis can occur. The Littoral zone is the shallow area near the shore where light reaches the bottom, allowing rooted plants to grow. The Profundal zone is typically aphotic (without light).

8. Bt Cotton is a genetically modified crop with a foreign gene from

Bt Cotton is a genetically modified crop with a foreign gene from

Bacillus thermolactis
Bacillus thuringiensis
Bacillus thermophilus
Bacillus tequilensis
This question was previously asked in
UPSC Geoscientist – 2023
The correct answer is Bacillus thuringiensis.
Bt Cotton is a genetically modified organism (GMO) that incorporates a gene from the soil bacterium *Bacillus thuringiensis* (Bt). This gene produces a protein toxin that is lethal to certain insect pests, particularly lepidopterans (like bollworms).
The Bt toxin is crystalline and requires alkaline conditions found in the gut of target insects to become active. It binds to receptors in the insect gut, causing pores and eventually leading to death. It is generally harmless to humans and other animals.

9. Which one of the following animals lays eggs to reproduce?

Which one of the following animals lays eggs to reproduce?

Dolphin
Seal
Platypus
Whale
This question was previously asked in
UPSC Geoscientist – 2023
The correct answer is Platypus.
The Platypus (Ornithorhynchus anatinus) is a monotreme, a group of mammals that lay eggs instead of giving birth to live young. Dolphins, seals, and whales are placental mammals and are viviparous, meaning they give birth to live offspring.
Monotremes are the most primitive group of mammals, and the only living examples are the platypus and four species of echidnas. They share characteristics of both mammals (like possessing mammary glands and fur) and reptiles (like laying eggs).

10. What is the number of chromosomes found in human somatic cell?

What is the number of chromosomes found in human somatic cell?

48
56
46
42
This question was previously asked in
UPSC Geoscientist – 2023
The correct answer is 46.
Human somatic (body) cells are diploid, meaning they contain two sets of chromosomes. Humans have 23 pairs of chromosomes, with one set of 23 chromosomes inherited from each parent. Thus, the total number of chromosomes in a human somatic cell is 23 * 2 = 46.
Of the 23 pairs, 22 are autosomes and one pair consists of sex chromosomes (XX in females, XY in males). Gametes (sperm and egg cells) are haploid and contain 23 chromosomes.