Many bacteria exist in biofilms in nature. Based on the information in the passage and in the chapter, is it possible to create a pure culture of a species that normally exists in biofilms?

(A) Yes, because many species can have planktonic growth or live within a biofilm, and a biofilm can contain a single species.
(B) Yes, because bacteria are most commonly found in sessile forms and a biofilm contains sessile bacteria.
(C) No, because a pure culture by definition must grow in medium and would not be able to form a biofilm.
(D) No, because biofilms always contain many species of bacteria and a pure culture does not.

answer : haversian

[explanation: -(compact bone is organized as parallel columns, known as haversian systems, which run lengthwise down the axis of long bones. these columns are composed of lamellae, concentric rings of bone, surrounding a central channel, or haversian canal, that contains the nerves, blood vessels, and lymphatic system of the bone)]

answer-

the statement that f(x) = |x+a| + b has exactly one x-intercept is sometimes correct.

solution-

it solely depends on b, whether the function will have one or two or zero x intercept.

this plot of the given function, f(x) = |x+a| + b will be the basic absolute value graph i.e v shape, with vertex translated to (-a, b), instead of origin.

1-   if b is zero, the graph will have exactly one x-intercept, at x= -a

2- if b is positive, the whole graph will be above the x-axis, hence it will have no x-intercepts.

3- if b is negative, the graph will be below the x-axis, hence it will have two x-intercepts.

∴ the statement is sometimes true.