These lack plastids

The correct option is bacterium, animals and fungi.

To understand why this is the correct choice, let us first define what plastids are and then examine the cellular characteristics of the organisms mentioned in the options.

1. What are Plastids?
Plastids are membrane-bound organelles found in the cells of plants, algae, and some other eukaryotic organisms. They are primarily responsible for activities related to making and storing food. The most common type of plastid is the chloroplast, which is responsible for photosynthesis. Other types include chromoplasts (for pigment synthesis and storage) and leucoplasts (for starch, fat, or protein storage). Because plastids contain their own DNA and ribosomes, they are thought to have evolved through endosymbiosis of an ancestral photosynthetic cyanobacterium.

2. Analyzing the Groups of Organisms:
• Bacteria (Prokaryotes): Bacteria are prokaryotic organisms. They lack membrane-bound organelles altogether, meaning they do not possess a nucleus, mitochondria, or plastids. While some bacteria (like cyanobacteria) are photosynthetic, they carry out photosynthesis using specialized internal membrane systems (thylakoids) rather than complex membrane-bound organelles like plastids.
• Animals (Eukaryotes): Animals are heterotrophic, multicellular eukaryotic organisms. Animal cells do not possess plastids. Instead, they rely on consuming organic matter from other organisms for energy.
• Fungi (Eukaryotes): Fungi are also heterotrophic eukaryotic organisms. Unlike plants, fungi cannot perform photosynthesis and obtain their nutrients by absorbing organic compounds from their surroundings. Therefore, fungal cells completely lack plastids.
• Plants (Eukaryotes): Plants are autotrophic eukaryotic organisms that perform photosynthesis. Consequently, plant cells contain chloroplasts and other types of plastids to synthesize and store food.

Conclusion:
Since bacteria, animals, and fungi all lack plastids in their cellular structure, the option "bacterium, animals and fungi" correctly identifies the groups that lack these organelles.