The passage describes how different groups of organisms are distinguished by their cellular features and kingdoms. Complete the passage by writing a suitable word or words in each of the spaces.
Plants are multicellular organisms that are able to carry out photosynthesis. Their cells contain chloroplasts and have cell walls made of (1) _____________. They store carbohydrates as (2) _____________. In contrast, bacteria are microscopic single-celled organisms. They do not have a nucleus but instead contain a circular chromosome of DNA. They may also possess small, circular loops of DNA called (3) _____________, which can be transferred between cells. An example of a useful bacterium is Lactobacillus (4) _____________, which is used in the production of yoghurt from milk. A pathogenic bacterium is Pneumococcus, which causes the disease (5) _____________.
Protoctists are a diverse group of microscopic single-celled organisms. Some, like Chlorella, resemble plants because they have chloroplasts, while others, like Amoeba, have features more like animal cells. A pathogenic protoctist is Plasmodium, which causes (6) _____________. Viruses are non-living particles that are smaller than bacteria. They can only reproduce inside (7) _____________ cells. Their structure consists of a protein (8) _____________ protecting their genetic material, which can be either (9) _____________ or RNA. An example of a plant-infecting virus is the tobacco (10) _____________ virus.
