Question

1. which of the following describes a \symbiotic relationship\?

a) a relationship where one organism always kills the other
b) a relationship where two species are interdependent
c) a process where organisms live without any contact with others
d) a process where microorganisms are grown in a sterile lab

1. what is the primary role of nitrogen - fixing bacteria like rhizobia?

a) to decompose dead animals in the soil
b) to convert atmospheric nitrogen into a usable form for plants
c) to protect plant leaves from being eaten by insects
d) to help plants absorb more sunlight

Explanation:

Question 5

A symbiotic relationship is a close and long - term interaction between two different biological species. In such a relationship, the two species are interdependent, meaning they rely on each other in some way (e.g., for food, shelter, or other resources). Option a describes a predatory or parasitic relationship (not symbiotic in the general sense). Option c describes organisms that are solitary, not in a symbiotic relationship. Option d is about culturing microorganisms in a lab, not a symbiotic relationship.

Nitrogen - fixing bacteria, like Rhizobia, have the ability to take atmospheric nitrogen ($N_2$), which is in a form that plants cannot directly use, and convert it into ammonia ($NH_3$) or other nitrogen - containing compounds that plants can utilize. Option a is the role of decomposers (like some fungi and bacteria), not nitrogen - fixing bacteria. Option c is the role of substances like pesticides or plant defenses, not nitrogen - fixing bacteria. Option d is not related to the function of nitrogen - fixing bacteria, as plants absorb sunlight through their chlorophyll and leaves, and nitrogen - fixing bacteria don't affect this process.

Answer:

b) A relationship where two species are interdependent

Question 6