Question

in which of the following organisms is a host cell required for reproduction? virus bacterial cell plant cell animal cell

Explanation:

Viruses are non - cellular entities. They lack the cellular machinery (like ribosomes for protein synthesis, enzymes for metabolic processes etc.) required for reproduction on their own. So, they must infect a host cell (which can be a bacterial cell, plant cell or animal cell depending on the type of virus). Once inside the host cell, they hijack the host's cellular machinery (such as using the host's ribosomes to make viral proteins, using host's nucleotides to replicate viral nucleic acid etc.) to reproduce. Bacterial cells can reproduce by binary fission (a form of asexual reproduction) without a host. Plant cells can reproduce asexually (e.g., by mitosis in meristematic tissues leading to growth and also some plants can reproduce vegetatively) or sexually (involving formation of gametes etc.) without needing another organism as a host. Animal cells can reproduce by mitosis (for growth, repair etc.) or meiosis (for gamete formation in sexual reproduction) in the context of the animal's own body and do not require a separate host organism for their basic reproductive processes (in terms of cell - level reproduction).

Answer:

virus