Some bacterial cells secrete a chemical that allows other bacterial cells to determine the density of bacterial cells in the area. They use this to determine if their population is large enough to begin certain functions, like forming a protective biofilm together. Based on this type of chemical signaling, which of the following demonstrates the same type of chemical signaling? (1 point)

B cells engaged in cell to cell recognition with helper T cells, exchanging antigen information the B cell has on its cell surface.

Cells that secrete oxytocin also use oxytocin for autocrine signaling, helping it to down-regulate production when needed.

During development, human nerve cells participate in paracrine signaling to determine what other nerve-cell types are in the area to adjust their placement.

Some animal cells can form junctions with other animal cells to directly share information.

7.
All of these are evidence of a common evolutionary ancestry for cell signaling except (1 point)

both bacteria and eukaryotic cells have receptors for intercellular signaling in their cell membranes

both plant and animal cells participate in cell junctioning

both plant and animal cell plastids code for cell membrane receptors

both unicellular bacteria and yeast have complex cell-signaling systems that use chemical messengers

8.
Examine the diagram of a cell membrane below:

Image of two sets of nucleated cells. On the left, two round cells are very close together. In the overlap of their membranes is a dashed line. Arrows indicate that a particle from the first cell travels to the second, while a particle from the second also travels to the first. The right hand image is exactly the same with one difference, these cells are rectangular shaped with much thicker cell membranes.

What type of reception does this representation depict? (1 point)

g protein-coupled receptor

receptor tyrosine kinase

intracellular receptor protein

ligand-gated ion channel

9.
A virus infects a lung cell and begins replication. The lung cell releases interferon into the extracellular environment where it can be picked up by other nearby cells. As a result, the other nearby cells slow down their protein-making machinery to slow down viral replication should they become infected. This is an example of what kind of communication? (1 point)

Cell-to-cell (membrane molecule) recognition

Cell junctions

Paracrine signaling

Synaptic signaling

10.
Muscle cells develop from embryonic precursor cells that have the potential to develop into a number of cell types. Which of the following best explains the particular conditions that commit them to becoming muscle cells? (1 point)

All the genetic material is transcribed, but only the genes required are translated.

Electrical signals are sent to the individual cells to turn on and off specific genes.

Signal cells send out chemical messages to nearby cells to change gene expression.

Specific cells have unique DNA that is only the portion required for its function.

11.
Below is a diagram illustrating how cells at the bottom of the early embryo are releasing chemicals to nearby cells.

A diagram representing how some embryonic cells release signaling molecules that are absorbed by nearby cells. If the signal is absorbed by the cell, it is transferred through the signal pathway into the nearby cell

What is the primary reason the signaling molecule is not received by every cell nucleus? (1 point)

All chemicals are absorbed by each cell, but only some enter the nucleus.

Chemicals are only released at predetermined times.

Signal pathways block some chemicals from transferring through the cell.

Signal-receiving cells may lack correct receptors.