.Answer:
Option A, fix nitrogen inside nodules on the roots of legumes
Explanation:
Rizhobium bacteria live in symbiotic relationship with roots of leguminous plants such as pulses including alfalfa, soybean etc.
Rhizobium or Bradyrhizobium is a gram negative bacteria that satisfies the nitrogen starvation of host plant.
These bacteria get habitation and nutrition from these leguminous plants and in return they fix the nitrogen into the nodules of the roots. This is a kind of facultative association between soil bacteria rizhobium and legume plants.
Hence, option A is correct
Thus, option A is correct
Testosterone is a steroid. Its physiological functions are:
Determines the the gender of a developing embryo
Development of reproductive organs and the prostrate gland in males
Responsible for secondary sexual characteristics in males such as deeper pitch, increased muscle bulk, hair on the upper lip
Regulates normal sperm development
Another is cholesterol. Physiological functions are:
Helps maintain the structure of cells and vessels improving overall health and function in the body.
Percursor to important sex hormones such as testosterone and estrogen.
Used as an insulator around nerves and is absolutely essential for brain function.
Precursor to Vitamin D, which supports a healthy immune and nervous system
<span>Dens (odontoid process) Hope this helps.</span>
Answer - Theory
Reasoning - Your best bet and term to describe the evolution by natural selection is theory as to still scientific theory/research is still ongoing and changes can be made in a different direction.