Agram-negative cell wall consists
a) cholesterol and peptidoglycan
b) peptidoglycan and cellulose
c) a thin layer of peptidoglycan surrounded by a capsule
d) a thin layer of peptidoglycan surrounded by an outer membrane containing lipopolysaccharides
e) a thick layer of peptidoglycan surrounded by an outer membrane containing lipopolysaccharides

The correct answer is D. A gram-negative cell wall consists of a thin layer of peptidoglycan surrounded by an outer membrane containing lipopolysaccharides.

Explanation:

Gram-negative bacteria are bacteria that do not retain the gentian violet dye during the Gram staining protocol.

During the Gram staining process, a contrast dye, usually safranin, is added after gentian violet, causing the Gram negative bacteria to stain pink or red. The contrast dye thus allows the visualization of Gram-negative bacteria which, because they have a thinner layer of peptidoglycans, cannot retain the gentian violet dye.

Its main feature is an endotoxin called lipopolysaccharide that causes pathogenicity and is responsible for its virulence.

the statement is true

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.