Chapter 10 Homework

Suppose there is a mutation in a laminin-binding integrin gene that causes a loss of function in the cytoplasmic domains of the integrin. Which one of the outcomes would you expect to observe as a result of this mutation?

The strength of tissues would decrease because the integrin could no longer associate with microfilaments.

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.

Epidermolysis bullosa is a set of rare genetic disorders that is caused by:

a keratin gene that disrupts intermediate filaments, weakening connections between epidermal cell layers.

Evidence that cytoskeletal elements have ancient origins comes from the:

ability to form functional hybrid microfilaments from actin monomers taken from distantly related organisms. sequence similarities of cytoskeletal elements when comparing distantly related organisms. observation that both prokaryotes and eukaryotes use cytoskeletal elements to assist cell division. presence of cytoskeletal elements in both eukaryotes and prokaryotes. All of these choices are correct.++

A decrease in cell-cell adhesion was caused by the introduction of an experimental substance that compromised the structural integrity of the tissue. Which type of cell junction would most likely be affected by this treatment given that the treatment caused a decrease in the strength of cell-cell adhesion?

adherens junctions

Which one of the choices matches a type of cell junction with the correct cytoskeletal element and cell adhesion molecules?

hemidesmosome, intermediate filament, integrin

Epithelial tissue is found:

lining the gastrointestinal tract. on the outer surface of the body. lining the lungs. All of these choices are correct.+++ lining blood vessels.

Which of the choices enable(s) the movement of cells?

microtubules and microfilaments

Which of the choices correctly lists the sequence in which the plant cell wall is synthesized?

middle lamella → primary cell wall → secondary cell wall