Some bacteria live in the roots of plants like soybeans and peas. what is the role of these bacteria in the nitrogen cycle?

a. to absorb nitrogen-containing compounds from the soil
b. to release free nitrogen into the atmosphere
c. to break down nitrogen-containing compounds in dead organisms
d. to convert free nitrogen into usable nitrogen

The correct answer is (d) To convert free nitrogen into usable nitrogen.

The nitrogen present in the soil is not directly used by the bacteria. It can be used only when the nitrogen is converted into usable form. These bacteria convert  atmospheric nitrogen into ammonia, then nitrite which is then converted into nitrate. This nitrate is used by the roots of the plants like soybeans and peas. This is the role of bacteria present in the roots of the plant to convert atmospheric nitrogen into usable form that can be used by plants.

1 digestive system

2 stomach

3 bladder

4 carbon deoxide

5 tiger

an individual’s sex (i.e., whether they are a male or female) is determined by the sex chromosomes. most people have two sex chromosomes, one that is inherited from their mother and one that is inherited from their father. typically, females have two x chromosomes (xx) and males have one x chromosome and one y chromosome (xy). conditions caused by changes (“mutations”) in genes located on the x chromosome are considered x-linked.

x-linked recessive inheritance

most x-linked conditions are recessive. this means that in a person with two x chromosomes (most females), both copies of a gene (i.e., one on each x chromosome) must have a change or mutation whereas in a person with one x chromosome (most males), only one copy of a gene must have a mutation. a female with a mutation in one copy of a gene on the x chromosome is said to be a “carrier” for an x-linked condition. a male with a mutation in a gene on the x chromosome is typically affected with the condition. because females have two copies of the x chromosome and males have only one x chromosome, x-linked recessive diseases are more common among males than females. however, x-linked recessive diseases can occur in both males and females.

for x-linked recessive disorders, an unaffected carrier mother who has a mutation in a gene on the x chromosome can transmit either the x chromosome with this mutation or a “normal” x chromosome to her children. if the father is unaffected, none of her daughters will be affected and all of her daughters will be unaffected—since they will inherit at least one normal x chromosome from their father. however, each daughter will have a 50% chance of being an unaffected carrier like her mother and a 50% chance of both x chromosomes being normal.