Which of the following is / are incorrect pairs regarding classification of biodiversity? 

1. Alpha diversity - Between-community diversity
2. Beta diversity - Within-Community diversity
3. Gamma diversity - Overall Biodiversity

Select the correct option from the codes given below:

A constitution amendment bill has also provisions pertaining to imposition, abolition, remission, alteration or regulation of a tax. Which of the following statements would hold correct for such a bill?

Consider the following rivers:

1. Tons
2. Betwa
3. Ken

Which of the above is/are tributary of Yamuna?

Consider the following statements:

1. The sulphur content in sour crude oil is higher in comparison to sweet crude oil
2. Brent crude oil is a sour crude oil
3. Most of Brent crude oil comes from North Sea

Which among the above statements is / are correct?

What is the main issue that has stalled the Doha round of negotiations, which have remained stalled since 2008?