121. In the context of ecosystem productivity, marine upwelling zones are important as they increase the marine productivity by bringing the
     1. decomposer micro-organisms to the surface.
     2. nutrients to the surface.
     3 bottom-dwelling organisms to the surface
     Which of the statements given above is/are correct ?

1. 1. 1 and 2

   
   
   

   2. 2 only

   
   
   

   3. 2 and 3

   
   
   

   4. 3 only

   
   
   

---

1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

---

122. Biodiversity forms the basis for human existence in the following ways :
     1. Soil formation
     2. Prevention of soil erosion
     3. Recycling of waste
     4. Pollination of crops
     Select the correct answer using the codes given below:

1. 1. 1, 2 and 3 only

   
   
   

   2. 2, 3 and 4 only

   
   
   

   3. 1 and 4 only

   
   
   

   4. 1, 2, 3 and 4

   
   
   

---

1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

---

---

123. There is a concern over the increase in harmful algae blooms in the sea waters of India. What could be the causative factors for this phenomenon ?
     1. Discharge of nutrients from the estuaries.
     2. Run-off from the land during the monsoon.
     3. Upwelling in the seas.
     Select the correct answer from the codes given below

1. 1. 1 only

   
   
   

   2. 1 and 2 only

   
   
   

   3. 2 and 3 only

   
   
   

   4. 1, 2 and 3

   
   
   

---

1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

---

124. Recently, "oilzapper" was in the news. What is it ?

1. 1. It is an eco-friendly technology for the remediation of oily sludge and oil spills

   
   
   

   2. It is the latest technology developed for under-sea oil exploration

   
   
   

   3. It is a genetically engineered high biofuel-yielding maize variety

   
   
   

   4. It is the latest technology to control the accidentally caused flames from oil wells

   
   
   

---

1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   NA

---

---

125. Human activities in the recent past have caused the increased concentration of carbon dioxide in the atmosphere, bu a lot of it does not remain in the lower atmosphere because of
     1. Its escape into the outer strato-sphere.
     2. The photosynthesis by phyto-plankton in the oceans.
     3. The trapping of air in the polar ice caps.
     Which of the statements given above is / are correct ?

1. 1. 1 and 2

   
   
   

   2. 2 only

   
   
   

   3. 2 and 3 only

   
   
   

   4. 3 only

   
   
   

---

1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

---