Yellowfin tuna, or thunnus albacores, are large sport fish that are found in tropical and subtropical waters around the world. they typically school under objects such as boats or patches of driftwood for protection from predators. schooling under these structures also provides yellowfin tuna with easy access to a food source such as smaller herbivorous fish that may be foraging for food around the structures. which trophic level does yellowfin tuna fill in a food chain? we

The answer is secondary consumer.

A trophic level of an organism shows its position in a food chain:

1. Producers, such as plants and algae, produce their own food and thus are the base of every food chain.

2. Primary consumers eat producers. They are herbivores that eat plants.

3. Secondary consumers eat primary consumers. They eat herbivores, so they are carnivores or omnivores.. 

4. The highest level is tertiary consumers that eat secondary consumers

According to this, and knowing than yellowfin tuna eat smaller herbivorous fish, it can be concluded that it belongs to the secondary consumers.

Ans.

Recombinant DNA (rDNA) represents DNA molecule, formed in laboratory conditions (in vitro) by recombining genetic material from different sources, using genetic engineering with new properties. The resulting recombinant molecule is then inserted to the host cell to get desired product.

Vector DNA helps in transport of DNA of interest to the host cell, where it replicates or expressed. The process that makes recombinant DNA involves joining of DNA of interest with vector DNA with the help of ligase enzymes at the sticky ends of DNA, produced by restriction enzymes.

Thus, the correct answer is option). 'the sticky ends of fragmented DNA are joined with vector DNA.'