Step 1: Understanding the concept of energy pyramids.
In a forest ecosystem, energy flow follows the law of energy conservation, where energy decreases as it moves up trophic levels, forming an upright pyramid.
Step 2: Analyzing the options.
(A) always inverted: Incorrect — In ecosystems like forests, the energy pyramid is upright. An inverted pyramid typically occurs in aquatic ecosystems.
(B) dumb-bell shaped: Incorrect — This is not a typical shape for an energy pyramid.
(C) spindle shaped: Incorrect — This does not accurately describe the energy pyramid.
(D) always upright: Correct — In a forest ecosystem, the energy pyramid is always upright, with producers at the bottom and consumers at higher trophic levels.
Step 3: Conclusion.
The correct answer is (D) always upright, as this is typical for energy pyramids in most ecosystems.
We do not clean natural ponds or lakes, whereas an aquarium or a swimming pool needs to be cleaned regularly. Why?
Identify the taxa that constitute a paraphyletic group in the given phylogenetic tree.
The vector, shown in the figure, has promoter and RBS sequences in the 300 bp region between the restriction sites for enzymes X and Y. There are no other sites for X and Y in the vector. The promoter is directed towards the Y site. The insert containing only an ORF provides 3 fragments after digestion with both enzymes X and Y. The ORF is cloned in the correct orientation in the vector using the single restriction enzyme Y. The size of the largest fragment of the recombinant plasmid expressing the ORF upon digestion with enzyme X is ........... bp. (answer in integer) 