Mastering Biology Unit 3 Chapter 6 & 7

Which of the following is the most common pathway taken by a newly synthesized protein that will be secreted by a cell?

**ER - Golgi - Vesicles that fuse with plasma membrane

Which of the following statements is a reasonable explanation for why unsaturated fatty acids help keep a membrane more fluid at lower temperatures?

The double bonds form kinks in the fatty acid tails preventing adjacent lipids from packing tightly.

A patient was involved a serious accident and lost a large quantity of blood. In an attempt to replenish body fluids, distilled water, equal to the volume of blood lost, is added to the blood directly via one of his veins. What will be the most probable result of this transfusion?

The patients red blood cells will swell and possibly burst because the blood has become hypo-tonic compared to the cells

Why are lipids and proteins free to move laterally in membranes?

There are only weak hydrophobic interactions in the interior of the membrane

When a cell is in equilibrium with its environment, which of the following processes occurs for substances that can diffuse through the plasma membrane?

There is random movement of substances into and out of the cell

Which of the following factors would tend to increase membrane fluidity?

a greater proportion of unsaturated phospholipids

A newly discovered unicellular organism isolated from acidic mine drainage is found to contain a cell wall, a plasma membrane, two flagella, and peroxisomes. Based just on this information, the organism is most likely ________.

a motel eukaryote

Cilia and flagella bend because of ________.

a motor protein called dynein

In plant cells, the middle lamella ________.

allows adjacent cells to adhere to one another

For a protein to be an integral membrane protein, it would have to be ________.

amphipathic with at least one hydrophobic region

Which domains of life are classified as prokaryotes?

bacteria and archaea

According to the fluid mosaic model of cell membranes, phospholipids ________.

can move laterally along the plane of the membrane

An animal cell lacking carbohydrates on the external surface of its plasma membrane would likely be impaired in which function?

cell-cell recognition

Which organelle often takes up much of the volume of a plant cell?

central vacuole

In what way do the membranes of a eukaryotic cell vary?

certain proteins are unique to each membrane

Which structure below is independent of the endomembrane system?

chloroplast

Which of the following types of molecules lack hydrophilic domains?

cholesterol

The force driving simple diffusion is ________, while the energy source for active transport is ________.

concentration gradient -- atp

According to the fluid mosaic model of membrane structure, proteins of the membrane are mostly

embedded in a lipid bilayer

Suppose a cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. It could be a cell from ________.

eukaryotic

Several epidemic microbial diseases of earlier centuries incurred high death rates because they resulted in severe dehydration due to vomiting and diarrhea. Today they are usually not fatal because we have developed which of the following types of treatments?

hydrating drinks with high concentrations of salt and glucose

If plant cells are grown on media containing radioactively labeled thymine for one generation, radioactively labeled macromolecules will be detected in which of the following?

in the nucleus, mitochondria and chloroplasts

According to the fluid mosaic model, a membrane ________.

is composed of a fluid bilayer of phospholipds with embedded amphipathic proteins

Which of the following statements about diffusion is true?

it is passive process in which molecules move from a region of higher concentration to a region of lower concentration

One primary advantage of light microscopy over electron microscopy is that ________.

light microscopy allows the visualization of dynamic processes in living cells

A bacterium engulfed by a white blood cell through phagocytosis will be digested by enzymes contained in ________.

lysosomes

Which of the following macromolecules enter the nucleus of a eukaryotic cell through pores in the nuclear membrane?

mRNA

Which of the following macromolecules leave the nucleus of a eukaryotic cell through pores in the nuclear membrane?

mRNA

Cyanide binds to at least one molecule involved in producing ATP. If a cell is exposed to cyanide, most of the cyanide will be found within the

mitochondria

Suppose a young boy is always tired and fatigued, suffering from a metabolic disease. Which of the following organelles is most likely malfunctioning in this disease?

mitochondria

Which of the following is the smallest structure that would most likely be visible with a standard (not super-resolution) research-grade light microscope?

mitochondria

Which organelle is the primary site of ATP synthesis in eukaryotic cells?

mitochondria

Which structure is common to plant and animal cells?

mitochondrion

Which of the following processes includes all of the others?

passive transport

Which cell would be best for studying lysosomes?

phagocytic white blood cell

White blood cells engulf bacteria using ________.

phagocytosis

When a plant cell, such as one from a tulip leaf, is submerged in a hypertonic solution, what is likely to occur?

plamolysis

Which of the following are found in plant, animal, and bacterial cells?

plasma membrane

Which of the following structures form cytoplasmic channels that connect adjacent plant cells through the cell walls?

plasmodesmota

Examination of a cell by transmission electron microscopy reveals a high density of ribosomes in the cytoplasm. This observation suggests that this cell is actively producing large amounts of which of the following molecules?

proteins

Proton pumps are used in various ways by members of every domain of organisms: Bacteria, Archaea, and Eukarya. What does this fact most probably mean?

proton gradients across a membrane were used by cells that were the common ancestor of all 3 domains of life

Which of the following frequently imposes a limit on cell size?

ratios of surface area to volume

In the fractionation of homogenized cells using differential centrifugation, which of the following will require the greatest speed to form pellets at the bottom of the tube?

ribosomes

You have a cube of modeling clay in your hands. Which of the following changes to the shape of this cube of clay will decrease its surface area relative to its volume?

round the clay up into a sphere

What kinds of molecules pass through a cell membrane most easily?

small and hydrophobic

Which of the following are least likely to diffuse through the phospholipid bilayer of a cell membrane?

small ions

Cell membranes have distinct inside and outside faces. Which of the following statements is the most likely explanation for the membrane's asymmetrical nature?

the two sides of a cell membrane face different environments and carry out different functions

A defect in which of the following intercellular junctions would allow partially digested material to leak passively between the cells of the small intestine into the abdominal cavity?

tight junction