Science Master

A. Ovary B. Kidney C. Liver D. Testis Solution: D Sertoli cells are found in the seminiferous tubule of the Testis. It helps in the process of production of sperm. The cells are activated by FSH hormone secreted by adenohypophysis and has FSH receptor on its membranes. These cells are required for male sexual development. Hence, option (D) is correct.  Read about Human Reproduction in NCERT Class 12 Chapter 3 .

A. Chlorofluorocarbon B. Carbon Dioxide C. Argon D. Methane Solution: C Greenhouse gases lead to greenhouse effect wherein the gases absorb the infrared radiation emitted by earth (after absorption of solar radiation reaching its surface) thereby increasing its temperature. Greenhouse effect is necessary but the rising concentrations of greenhouse gases due to human activities has caused great alarm.  The main greenhouse gases are- Carbon dioxide, Methane, Nitrous oxide, Hydrofluorocarbons, Ozone, HCFCs, etc.  Hence, option (C) is correct. Check out official Answer key of UPPCS Prelims 2022 Exam . 

A. Liver B. Brain C. Heart D. Kidney Solution: A Hepatitis A is an inflammation of the liver that is caused by hepatitis A virus. Hepatitis A is a highly contagious, short-term liver infection. In rare cases, it can cause liver failure and even death. It can spread from the infected person when in personal contact or through contaminated food or drink. Symptoms usually appear 2 to 7 months after infection. Some of the symptoms are: Yellow skin or eyes Loss of appetite and Upset stomach Vomiting and Stomach pain Fever Dark urine or light- colored stools Diarrhea Joint pain Feeling tired Hence, option (A) is correct. 

A. Non-biodegradable pollutant B. Biochemical pollutant C. Non-pollutant D. Biodegradable pollutant Solution: A Dichloro-diphenyl-trichloroethane (DDT) is a non-biodegradable pollutant. It was used as an insecticide in agriculture. It was banned globally for agricultural use under the Stockholm Convention on Persistent Organic Pollutants which has been in effect since 2004. In many countries, DDT is still used to control mosquitoes that spread malaria.  Müller was awarded the Nobel Prize in Physiology or Medicine in 1948 "for his discovery of the high efficiency of DDT as a contact poison against several arthropods". DDT was first synthesized in 1874. Hence, option (A) is correct. Check out UPPCS Prelims 2022 Answer Key . Join UPPCS Mains 2022 Test Series .

(A) a large aperture contributes to the quality and visibility of the images.  (B) a large area of the objective ensures better light gathering power.  (C) a large aperture provides a better resolution.  (D) all of the above. Solution: D A lens of large focal length and large aperture is best suited as an objective of an astronomical telescope since a large aperture provide better resolution and contributes to the quality and visibility of the images. A large area of the objective ensures better light gathering power.  Hence, option (D) is correct.

A. Forever Revolution B. Green Revolution C. Farm-fresh Revolution D. Evergreen Revolution Solution: D M S Swaminathan, also known as Father of Green Revolution in India, coined the term Evergreen Revolution in 1990. The term implies the productivity improvement in perpetuity without ecological and social harm.  M S Swaminathan was named the first World Food Prize Laureate for developing and introducing high-yielding wheat and rice varieties in India during 1960s.  Hence, option (D) is correct. Read about various agricultural revolutions in India . 

A. Ficus B. Lentils C. Chickpeas D. Peanuts Solution: A Clover, Soybeans, Alfalfa, Lupins, Rooibos, Cowpeas, Peanuts, and Chickpeas are some plants that fix atmospheric nitrogen due to a mutualistic symbiotic relationship with rhizobia bacteria found in their root nodules. Ficus is a genus of around 900 species of trees, shrubs, and vines in the family Moraceae.  Hence, option (A) is correct. Read more about Plant Diseases . 

(1) Species A (−) ; Species B (0)  (2) Species A (+) ; Species B (+)  (3) Species A (−) ; Species B (−)  (4) Species A (+) ; Species B (0) Solution: 1 Types of symbiotic relationships: 1. Mutualism- Both species benefit i.e. Species A (+); Species B (+) 2. Commensalism- In which one species benefits and the other remains unaffected i.e. Species A (+); Species B (0) 3. Parasitism- One species benefits from the relationship at the expense of the other i.e. Species A (+); Species B (-) 4. Amensalism- One species is harmed or killed by the other and one is unaffected by the other i.e. Species A (-); Species B (0) Hence, option (1) is correct.