Which of the following uses a particularly dense suite of tight junctions to prevent microbes from entering the underlying tissue?
the mucociliary escalator
the epidermis
the blood-brain barrier
the urethra

Blood-brain barrier.

Explanation:

Blood brain barrier may be defined as the barrier between the blood capillaries and the component of the brain tissue. This blood brain barrier provide protection against the pathogens present in the blood.

The blood-brain barrier uses tight junctions that prevent the entry of microbes in the underlying tissue. The tight junctions allows only the entry of some selected particles and prevent the entry of other particles.

Thus, the correct option is (3).

the answers are as following:

1. c. double helix, nucleosome, coil, supercoil, chromosome

2. b. g2 phase, preparation for mitosis

3. d. interphase consists of the g1, s, and g2 phases

4. c. metaphase

5. a. chromosomes are duplicated before cell division so that each new daughter cell has a complete set