bio chapter 5 and 4 questions
Which of the following statements is part of the cell theory? All living organisms are made of cells. All cells contain DNA that they pass on to daughter cells. All cells depend on their surroundings to provide energy. All cells have a nucleus.
All living organisms are made of cells.
What is a difference between prokaryotic and eukaryotic cells?
Both cells have cytoplasm but prokaryotic cells lack a nucleus.
. Some animal cells produce an extensive extracellular matrix. You would expect their ribosomes to synthesize large amounts of which of the following proteins?
Collagen
Which of the following explains why active movement of molecules across membranes must function continuously?
Diffusion allows movement down the concentration gradient to maintain equilibrium.
Why must active transport of molecules across plasma membranes function continuously?
Diffusion cannot occur in certain cells.
. How would an organism maintain membrane fluidity in an environment where temperatures fluctuated from very high to very low?
Greater proportion of unsaturated phospholipids in membranes.
In what important way does receptor-mediated endocytosis differ from phagocytosis?
It brings in only a specifically targeted substance.
What happens to the membrane of a vesicle after exocytosis?
It fuses with and becomes part of the plasma membrane.
Which of the following produces the energy needed for protein synthesis in the endomembrane system?
Mitochondria
. Eukaryotic cells contain complex organelles that carry out their chemical reactions. While prokaryotes lack many of these complex organelles, they have a variety of unique structures of their own. Most prokaryotic cells can, however, exchange nutrients with the outside environment faster than most eukaryotic cells. Why is this so?
Most prokaryotic cells are smaller and have a higher surface area-to-volume ratio than eukaryotic cells.
Which of the following observations contributed to cell theory? Animal and plant cells have nuclei and organelles. Non-living material cannot give rise to living organisms. Prokaryotic and eukaryotic cells are surrounded by a plasma membrane. Viruses replicate.
Non-living material cannot give rise to living organisms.
What is the difference between primary and secondary active transport?
Primary active transport is directly dependent on ATP, while secondary active transport is indirectly dependent on ATP.
Which of the following molecules will be affected if the extracellular matrix of a cell begins to break down?
Proteoglycans
Who was the first to clearly identify and name individual cells?
Robert Hooke
. In addition to a plasma membrane, a eukaryotic cell has organelles, such as mitochondria, that also have membranes. In which way would these membranes differ?
The proportion of phosphate within the phospholipids will vary.
. Which of the following questions can be asked about organisms that live in fresh water?
Will their bodies take in too much water?
What problem is faced by organisms that live in fresh water?
Without compensating mechanisms, their bodies tend to take in too much water.
When viewing a specimen through a light microscope, what is a method that scientists use to make it easier to see individual components of cells?
a beam of electrons
Which of the following is most likely to have the greatest concentration of smooth endoplasmic reticulum (SER)?
a cell that makes steroid hormones
. Which of the following could most effectively be visualized with a scanning electron microscope? cells swimming in a drop of pond water. details of structures inside cells a three-dimensional view of the surface of a membrane the movement of molecules inside the cell
a three-dimensional view of the surface of a membrane
When bacteria lack fimbriae, what are they less likely to do?
adhere to cell surfaces
How does the sodium-potassium pump make the interior of the cell negatively charged?
by expelling more cations than it takes in
According to the fluid mosaic model of the plasma cell membrane, what is the location of carbohydrates in the cell membranes?
carbohydrates are present only on the exterior surface of a membrane
What is the basic unit of life?
cells
. Which of the following structures is not found in prokaryotic cells?
chloroplast
What process is used by prokaryotes to obtain some materials and remove waste?
diffusion
Water moves via osmosis across plasma cell membranes in which direction?
from an area with a high concentration of water to one of lower concentration
Where would you find DNA, the genetic material, in an animal cell?
in the mitochondria and the nucleus
Which components of the cytoskeleton are responsible for the contraction of muscles?
microfilaments
Which of the following will disassemble and reform quickly when white blood cells need to move quickly to the site of an infection?
microfilaments and microtubules
Which of the following do not play a role in intracellular movement?
only intermediate filaments
Which plasma membrane component can be either found on its surface or embedded in the membrane structure?
protein
Gap junctions are formed by ________.
protein complexes that form channels between cells
Which of the following is found both in eukaryotic and prokaryotic cells?
ribosomes
. What do double bonds in phospholipid fatty acid tails contribute to?
the fluidity of membranes
Which of the following is an example of passive transport across a membrane?
the movement of water from a nephron into the collecting duct of the kidney
Which of the following is surrounded by two phospholipid bilayers?
the nucleus
What type of junctions prevent the movement of chemicals between two adjacent animal cells?
tight junctions
. Which characteristic of a phospholipid, shown here, increases the fluidity of the membrane?
unsaturated fatty acid tail
. Peroxisomes got their name because hydrogen peroxide is ______.
used in their detoxification reactions
In plant cells, the function of the lysosomes is carried out by what?
vacuole
