1. Which of the following is NOT an example of symbiosis?
A) bacteria in the human colon
B) tapeworm in the human intestine
C) tuberculosis in the human lung
D) protozoa in termites
E) microbes passing across the placenta to the fetus
C) tuberculosis in the human lung
The correct answer is C) tuberculosis in the human lung. This is not an example of symbiosis because tuberculosis is a disease caused by the bacteria Mycobacterium tuberculosis and it harms the host rather than benefiting it. Symbiosis is a close and long-term interaction between two different species, where at least one of the species benefits. In contrast, tuberculosis is a parasitic infection that causes harm to the host organism.
To determine which of the options is NOT an example of symbiosis, we need to understand what symbiosis is.
Symbiosis refers to a close and long-term relationship between two different organisms of different species, where at least one organism benefits from the interaction.
Now, let's examine each option and see if it fits the definition of symbiosis:
A) Bacteria in the human colon: This is an example of symbiosis. Bacteria in the colon help in the digestion of food and produce certain vitamins, which benefits both the bacteria and the human host.
B) Tapeworm in the human intestine: This is also an example of symbiosis. The tapeworm benefits by obtaining nutrients from the human host, while the host may experience negative effects from the presence of the tapeworm.
C) Tuberculosis in the human lung: This is not an example of symbiosis. Tuberculosis is a disease caused by a bacterium, which invades and harms the human host. There is no mutual benefit in this relationship.
D) Protozoa in termites: This is an example of symbiosis. The protozoa live in the termite's gut and help in the digestion of cellulose, which is the main component of wood. The termite benefits from the ability to break down cellulose and obtain nutrients from it.
E) Microbes passing across the placenta to the fetus: This is not an example of symbiosis. When microbes pass across the placenta to a fetus, it can lead to infection and harm the fetus. Again, there is no mutual benefit in this relationship.
Based on this analysis, the correct answer is C) tuberculosis in the human lung, as it is not an example of symbiosis.