Bio 2170 Chapter 10 LearningCurve

Cadherins bind to which type of cytoskeletal element(s)?

both intermediate filaments and microfilaments

Predict what would happen if an embryonic epidermal cell switched from expressing E-cadherin to N-cadherin.

The cell would leave the epidermis and adhere to neural cells.

What is the advantage of forcing materials to travel through cells instead of between cells? All of these choices are correct. Cells can control which materials are transported. The exposure in internal tissues to the outside environment is limited. Exposure to bacteria or viruses is limited.

All of these choices are correct.

________is a specific type of extracellular matrix.

Basal lamina

If intermediate filaments were capable of dynamic instability, what outcome would be most likely?

Cell shape and support would be affected.

_________ could be a part of the extracellular matrix made by a plant cell. Collagen Lignin Laminin Elastin

Lignin

Could melanin granules be moved by dynein and kinesin along an actin microfilament?

No, these motor proteins are specific to microtubules and cannot move along microfilaments.

The epidermis contains several layers and receives its nutrients from the dermis by diffusion. What explains why the outermost layers of the epidermis consist of dead cells?

One of the major functions of the epidermis is forming a waterproof barrier. Once that barrier is formed, nutrients cannot pass through it and the cells beyond that layer die.

Imagine that you are examining a mouse that does not produce basal lamina in the skin. How will this mouse be different from a normal, wild-type mouse?

The cells of the epidermis would not be properly connected to form a water-resistant barrier.; The epidermis will not be connected to the dermis.

Which of the statements about the skin is true?

The epidermis is made up of epithelial tissue whereas the dermis is made up primarily of connective tissue.

A patient in a physician's office has a deep cut, and as it is being stitched up, a sample of tissue is taken for testing. Analysis of the tissue reveals it has few cells, surrounded by a large amount of extracellular matrix proteins with some blood vessels, sweat glands, and nerve cells. What kind of tissue is this?

The tissue is most likely dermis, and should also have some fibroblasts, but few keratinocytes and melanocytes.

A researcher is assessing the expression of a specific protein in cells. This protein appears as a "web" in the cytoplasm of cells. The protein is likely:

a component of the cytoskeleton.

Microvilli are located on the ______ of an intestinal cell.

apical surface

A researcher is studying a population of mutant fibroblasts that fail to flatten and attach to extracellular matrix proteins on a flat surface. This is likely the result of mutations in genes encoding:

components of cell junctions.

Structures known as microvilli are associated with:

increased surface area for nutrient absorption.

In skin, the cells of the epidermis connect to the basal lamina through cellular junctions known as hemidesmosomes. Select the cytoskeletal element that helps maintain the integrity of this connection.

intermediate filaments

Macrophage cells undergo a process called phagocytosis in which material is brought into a cell in the form of membrane vesicles and then transported along microtubules toward the cell center. Assuming that the centrosome is near the cell center, you can predict that these vesicles are moving to the _____ end of microtubules using the motor protein _____.

minus end; dynein

Which type of cellular junction(s) allow(s) for the movement of proteins and transfer RNA molecules?

plasmodesmata only

In nerve cells, the centrosome is located near the nucleus. Vesicles move from near the nucleus to the end of long extensions (axons) along microtubules. Based on these two facts, it is possible to conclude that these vesicles are moving in the _____ direction on the microtubule using the motor protein _____.

plus end; kinesin

Metastatic cancer cells have a dynamic actin cytoskeleton associated with their plasma membrane. The presence of the membrane cytoskeleton most likely accounts for:

the ability of these cells to move and crawl to new locations in the body.

The molecule lignin is associated with which property of a cell wall?

water resistance