The condition characterized by a lack of melanin in skin, hair, and eyes is: MCQ with Answer and Explanation

Explanation:
DNA polymerase catalyzes the formation of phosphodiester bonds between adjacent nucleotides, extending the new strand complementary to the template. Helicase unwinds DNA, ligase joins fragments, primase synthesizes RNA primer. In prokaryotes, DNA polymerase III is the main replicative enzyme.

Explanation:
Red tides are harmful algal blooms caused primarily by the rapid multiplication of certain marine dinoflagellates, such as Gonyaulax. These blooms discolor the water red or brown and release potent toxins (like saxitoxin) that can kill marine life and cause paralytic shellfish poisoning in humans who consume contaminated seafood. Cyanobacteria can cause freshwater blooms, but not marine red tides.

Explanation:
Retroviruses (e.g., HIV) possess two copies of single-stranded RNA and the enzyme reverse transcriptase, which transcribes the RNA into DNA upon infection. This DNA integrates into the host genome. Other viruses may have dsDNA, ssDNA, or dsRNA, but the defining feature of retroviruses is the RNA genome and reverse transcription.