Question

(a) Based on Figure 1, describe TWO pieces of evidence a researcher could use to support the

claim that apicoplasts evolved from free-living, prokaryotic organisms.
(b) Doxycycline is a drug used to treat malaria and some bacterial infections. Doxycycline binds
to the prokaryotic 30S ribosomal subunit and inhibits its function. Explain how doxycycline can
be an effective treatment for a P. Falciparum infection in humans. ​

Answer 1

The apicoplast is an organelle found in some protists, including Plasmodium falciparum, the parasite that causes malaria. The apicoplast is believed to have evolved from a free-living, photosynthetic, prokaryotic organism through a process known as endosymbiosis. During this process, the prokaryotic organism was engulfed by another cell and eventually became an organelle within that cell.

Doxycycline is a drug that works by inhibiting the function of the prokaryotic ribosomes in bacteria. However, since the apicoplast of Plasmodium falciparum is also believed to have evolved from a prokaryotic organism, it contains prokaryotic ribosomes that are targeted by doxycycline. By inhibiting the function of these ribosomes, doxycycline can effectively kill the Plasmodium falciparum parasites that cause malaria.

It is worth noting that doxycycline is not the primary drug used to treat malaria, and is typically only used in combination with other drugs as part of a broader treatment strategy.