Consider the following statements regarding the pyramid of numbers in an ecosystem:
1. The pyramid of numbers is not always upright.
2. A grassland ecosystem and a pond ecosystem show an inverted pyramid of numbers.
3. A forest ecosystem is an example of a partially upright pyramid.
Which of the above statements is/are correct?1
1 and 2 only
2
2 and 3 only
3
1 and 3 only
4
All of the above