Practice UPSC CSAT 2021 PYQs

Directions for the following 4 (four) items : Read the following four passages and answer the items that follow. Your answers to these items should be based on the passages only.

Passage - 2

Approximately 80 percent of all flowering plant species are pollinated by animals, including birds and mammals, but the main pollinators are insects. Pollination is responsible for providing us with a wide variety of food, as well as many plant-derived medicines. At least one-third of the world's agricultural crops depend upon pollination. Bees are the most dominant taxa when it comes to pollination and they are crucial to more than four hundred crops. Pollination is an essential service that is the result of intricate relationships between plants and animals, and the reduction or loss of either affects the survival of both. Effective pollination requires resources, such as refuges of pristine natural vegetation.

On the basis of the passage given above, the following assumptions have been made :

1. Sustainable production of India's cereal food grains is impossible without the diversity of pollinating animals.

2. Monoculture of horticultural crops hampers the survival of insects.

3. Pollinators become scarce in cultivated areas devoid of natural vegetation.

4. Diversity in insects induces diversity of plants.

Which of the above assumptions is/are valid ?

Passage - 3

A study conducted on the impacts of climate change over the Cauvery basin of Tamil Nadu using regional climate models showed an increasing trend for maximum and minimum temperatures, and a decrease in the number of rainy days. These climatic shifts will have an impact on the hydrological cycles in the region, lead to more run-off and less recharge, and affect the groundwater tables. Further, there has been an increase in the frequency of droughts in the State. This has driven farmers to increase dependency on groundwater resources to secure their crops.

Which one of the following statements best reflects the crux of the passage given above ?

Passage - 4

Researchers were able to use stem cells to gauge the neurotoxic effects of the environmental pollutant Bisphenol A (BPA). They used a combination of biochemical and cell-based assays to examine the gene expression profile during the differentiation of mouse embryonic stem cells upon treatment with BPA, a compound known to cause heart diseases, diabetes, and developmental abnormalities in humans. They were able to detect and measure BPA toxicity towards the proper specification of primary germ layers, such as endoderm and ectoderm, and the establishment of neural progenitor cells.

On the basis of the passage given above, the following assumptions have been made :

1. BPA may alter embryonic development in vivo.

2. Biochemical and cell-based assays are useful in finding out treatments for pollution-induced diseases.

3. Embryonic stem cells could serve as a model to evaluate the physiological effects of environmental pollutants.

Which of the above assumptions are valid ?

If 3²⁰¹⁹ is divided by 10, then what is the remainder ?

The number 3798125P369 is divisible by 7. What is the value of the digit P ?

From January 1, 2021, the price of petrol (in Rupees per litre) on m^th day of the year is 80 + 0·1m, where m = 1, 2, 3, ..., 100 and thereafter remains constant. On the other hand, the price of diesel (in Rupees per litre) on n^th day of 2021 is 69 + 0·15n for any n. On which date in the year 2021 are the prices of these two fuels equal ?

A biology class at high school predicted that a local population of animals will double in size every 12 years. The population at the beginning of the year 2021 was estimated to be 50 animals. If P represents the population after n years, then which one of the following equations represents the model of the class for the population ?

In a class, 60% of students are from India and 50% of the students are girls. If 30% of the Indian students are girls, then what percentage of foreign students are boys ?

A Statement followed by Conclusion-I and Conclusion-II is given below. You have to take the Statement to be true even if it seems to be at variance from the commonly known facts. Read all Conclusions and then decide which of the given Conclusion(s) logically follows/follow from the Statement, disregarding the commonly known facts.

Statement : Some radios are mobiles. All mobiles are computers. Some computers are watches.

Conclusion-I : Certainly some radios are watches.

Conclusion-II : Certainly some mobiles are watches.

Which one of the following is correct ?

Directions for the following 4 (four) items : Read the following four passages and answer the items that follow. Your answers to these items should be based on the passages only.

Passage - 1

Fig trees (genus Ficus) are considered sacred in India, East Asia and Africa and are common in agricultural and urban landscapes where other large trees are absent. In natural forests, fig trees provide food for wildlife when other resources are scarce and support a high density and diversity of frugivores (fruit-eating animals). If frugivorous birds and bats continue to visit fig trees located in sites with high human disturbance, sacred fig trees may promote frugivore abundance. Under favourable microclimate, plenty of seedlings of other tree species would grow around fig trees.

On the basis of the passage given above, the following assumptions have been made :

1. Fig trees can often be keystone species in natural forests.

2. Fig trees can grow where other large woody species cannot grow.

3. Sacred trees can have a role in biodiversity conservation.

4. Fig trees have a role in the seed dispersal of other tree species.

Which of the above assumptions is/are valid ?