A researcher notices a connection between two cells. Upon further analysis, he concludes that there is no exchange of water or ions between the cells. Which of the following could be the identity of the connection between the two cells?

A researcher observes a sample of cells and concludes that they are connected by desmosomes. What observation(s) could have led to this conclusion?

I. He notices that there is no fluid exchange between the cells

II. There is a connection between the intermediate filaments of each cell

III. The connection occurs at a single location

Action potential propagation in cardiac cells is very important for the proper functioning of the heart. Which of the following intercellular connections will be most effective in cardiac cells?

Which of the following criteria does not help differentiate between prokaryotes and eukaryotes?

Which cellular junction involves the direct attachment of cytoskeletons between adjacent cells?

A patient is found to have a defect in his intermediate filaments. Which of the following cellular junctions will be absent in this patient?

I. Desmosomes

II. Gap junctions

III. Hemidesmosomes

A researcher is analyzing an autoimmune disease. His results indicate that the patient has antibodies that attack occludin proteins. Which of the following is likely true for this patient?

Zona occludens are formed at __________ junctions and desmosomes are formed at __________ junctions.

Which of the following is true regarding desmosomes and hemidesmosomes?

One component of the immune system is the neutrophil, a professional phagocyte that consumes invading cells. The neutrophil is ferried to the site of infection via the blood as pre-neutrophils, or monocytes, ready to differentiate as needed to defend their host.

In order to leave the blood and migrate to the tissues, where infection is active, the monocyte undergoes a process called diapedesis. Diapedesis is a process of extravasation, where the monocyte leaves the circulation by moving in between endothelial cells, enters the tissue, and matures into a neutrophil.

Diapedesis is mediated by a class of proteins called selectins, present on the monocyte membrane and the endothelium. These selectins interact, attract the monocyte to the endothelium, and allow the monocytes to roll along the endothelium until they are able to complete diapedesis by leaving the vasculature and entering the tissues.

The image below shows monocytes moving in the blood vessel, "rolling" along the vessel wall, and eventually leaving the vessel to migrate to the site of infection.

Movement between cells, such as that carried out by monocytes in the passage, is typically blocked best by which kind of cell junction?