Cell Biology Answers

8. In the histologic specimen of connective tissue stained with hematoxylin-eosin one can see ramifying cells that are in contact with one another. In general the cells form a network structure the spaces of which contain cord of lymphocytes. One of the students said that that tissue is reticular tissue, another student said that it is bony tissue. Which of the answers is correct?

7. The process of hemopoiesis depends on surrounding tissues (inner environment). Cells of what tissue make up that inner environment?

6. Connective tissue, characterized by a relatively large number of densely spaced fibers, arrangement strictly ordered, and an insignificant amount of cellular elements and the main substance between them?

5. Papillary layer and reticular layer of the derm are characterized by different structural features. What tissues make up those layers?

4. There are two histologic specimens of fibrous connective tissue. The both histologic specimens are characterized by presence of numerous bundles of collagen fibres and small amount of ground substance. But in one of the histologic specimens the collagen fibres run in parallel way, and in the other histologic specimen the collagen fibres are irregularly arranged. What tissues are those?

The cellular slime mold Dictyostelium discoideum is a eukaryote that lives on the forest floor as

independent motile cells. When their food supply is exhausted, the amoeba, stop dividing and gather

together to form tiny, multicellular worm like structures, which crawl about as glistening slugs and leave

trails of slime behind them. How do individual amoebae know when to stop dividing and how to find their way into a common aggregate?

It was shown that amoebae aggregate if placed on a glass coverslip under water, provided that simple salts are present. The center of aggregation pattern can be removed with a pipette and placed in a field of fresh amoebae, which immediately start streaming toward it. What does this imply?

Four experiments were designed to determine the nature of the signal by using an existing center of

aggregation as the source of the signal and previously unexposed amoebae as the target cells. The

arrangements of aggregation centers are shown in the figure * below.

What do the results show?

How might the location of chloroplasts within these cells be advantageous in light absorption? 

What type of connective tissue of the newborn children consists of adipocytes that contain numerous fat cytoplasmic?

There is a histologic specimen of loose irregular fibrous connective tissue stained with the dye specific for acid phosphatase (enzyme of lysosomes). Some of the cells in that histologic specimen are characterized by high activity of the enzyme. What cells are those, and what function do they perform.

3. Structural diagram of loose irregular fibrous connective tissue.

Cells and fibres of loose irregular fibrous connective tissue are characterized by structural features. It is necessary to examine the diagram and describe the structural features of the cells and fibres. What function do they perform?