Chapter 4 - Homework Quesions

Receptor proteins

bind to a signal molecule and bring about a cellular response.

Chromosomes are made from

condensed chromatin.

A prokaryotic cell

does not have a membrane-bound nucleus.

Below is a diagram of a bacterium. What part of the bacterial cell does Z represent?

flagella

Identify the organelle - function pairing that is mismatched.

flagella - contain digestive enzymes that can digest molecules or cellular components

Maya would like to observe a live paramecium—a single-celled organism that is about 50-300 μm long. The best device to do this would be a(n)

light microscope.

The cell walls of bacterial cells and plant cells function in

maintaining cell shape.

Viruses can be viewed with

an electron microscope.

Which of the following is NOT a function of the extracellular matrix in animal cells?

provides a channel for water and ion flow between adjacent cell walls

What function does the nucleolus have?

synthesizes ribosomal RNA

Which of the following allows eukaryotic cells and their organelles to move?

the cytoskeleton

A cell that cannot produce enough energy to function properly most likely has a problem with its

mitochondria.

The stack of thylakoids labeled "A" in this figure is called

granum.

Which organelle modifies the contents within vesicles and then repackages them for export?

Golgi apparatus

As a molecule moves through the plasma membrane it passes through

a hydrophilic layer of phospholipid heads, then a hydrophobic layer of phospholipid tails, and then another hydrophilic layer of phospholipid heads.

There is an antibiotic called streptomycin that inhibits the function of bacterial ribosomes. Consequently, as the bacterial cells die, the person taking the antibiotics gets better. In other words, the antibiotic destroys bacteria by

not allowing them to produce proteins.

Which of the following structures would NOT be found in a prokaryotic cell?

nucleus

The nucleus has a double membrane that encloses the DNA. Inside the nucleus, the DNA acts as the template to produce mRNA and ribosomes. To exit the nucleus, these molecules must

pass through pores that span both membranes.

What must materials pass through to enter or leave a cell?

plasma membrane

Which feature is found in all cells?

plasma membrane composed of phospholipids