Which group of plants have nitrogen fixing bacteria in their root nodules?
A. Grass.
B. Phytoplankton.
C. Legumes.
D. Seaweeds.
http://docs.google.com/viewer?a=v&q=cache:vHwvaOg-h7MJ:aces.nmsu.edu/pubs/_a/a-129.pdf+nitrogen+fixing+bacteria+in+their+root+nodules&hl=en&gl=us&pid=bl&srcid=ADGEESiaRVNVNto8nCSOgbDMLkPikjAlEzPJJUv3YLAHYPxesZ699NI8Y9frETCkcfYmcA6hUVzEruc0d-6-bOKCSAlZXJwQCNVPsc4-FiEQKBRggUpb4aJr1c9TM0d-Fb9oH8WDwx0M&sig=AHIEtbSQKegiGxpYPAH0RbhbeLvUMWOZqQ
To find the correct answer to this question, we need to understand the concept of nitrogen fixation. Nitrogen fixation is the process by which certain bacteria convert nitrogen gas from the atmosphere into a form that plants can utilize, such as ammonia. Some plants have a mutualistic relationship with these nitrogen-fixing bacteria, where the bacteria live in the root nodules of the plant and provide it with nitrogen compounds in exchange for carbohydrates and other nutrients.
Now, let's analyze the options given:
A. Grass: Grasses, in general, do not have a significant association with nitrogen-fixing bacteria. They rely on nitrogen availability in the soil.
B. Phytoplankton: Phytoplankton are tiny, free-floating marine plants found in bodies of water. While some phytoplankton species may be associated with bacteria, they do not typically form root nodules or have a well-known relationship with nitrogen-fixing bacteria.
C. Legumes: Legumes, which include plants like peas, beans, lentils, and clover, are well-known for their symbiotic relationship with nitrogen-fixing bacteria. They possess specialized root nodules where nitrogen-fixing bacteria reside, enabling them to convert atmospheric nitrogen into a form that plants can use.
D. Seaweeds: Seaweeds, also known as marine macroalgae, are large marine algae that can be found in both shallow and deep waters. Although they play a crucial role in marine ecosystems, they do not have a direct association with nitrogen-fixing bacteria in root nodules.
Based on this analysis, the correct answer is C. Legumes, as they are the group of plants that have nitrogen-fixing bacteria in their root nodules.