mastering biology ch 4

1 meter = _____ centimeters.

100; A centimeter is 1 hundredth of a meter.

Athletes can apply for an exception to use a banned substance if it is used for medical purposes. Which of the following athletes is most likely to be allowed to use meldonium if she or he is using it for its original intended purpose?

A professional runner using it for a heart condition

Which of these structures stores, modifies, and packages products?

A; The Golgi apparatus modifies, stores, and packages products of the ER.

The structure that regulates the passage of material into and out of this bacterial cell is indicated by the letter _____.

C; The plasma membrane is selectively permeable.

__________ is the most prevalent glycoprotein in the extracellular matrix

Collagen; Collagen can comprise 40% of the protein in your body.

Which of these is the double membrane that encloses the nucleus?

E; This is the nuclear envelope.

You get a bacterial infection. Which of the following will your immune system do to try and eliminate it?

Either force excess zinc into the invading bacteria or starve them of zinc.

You are a genetic engineer. You devise a way to alter the bacterial gene that codes for CzrA, causing this protein to malfunction. Which of the following are you trying to aid in humans?

Immune system

Chloroplast

Makes food by converting light energy into chemical energy

Golgi Apparatus

Modifies and packages proteins

cell labeled with oxygen-metabolizing bacterium

Oxygen metabolizing bacterium begins to be engulfed by ancestral cell.

Which of the following is true?

Proteins with the same structure can have different functions in different organisms.

What name is given to the process in which pre-mRNA is edited into mRNA?

RNA processing; RNA processing edits the RNA transcript that has been assembled along a DNA template.

Why would a professional athlete be interested in using meldonium?

To enhance endurance.

ribosome

Works with mRNA to synthesize proteins.

Polypeptides are assembled from _____.

amino acids; Proteins are composed of amino acid monomers.

_____ is/are identical in structure to centrioles.

basal bodies; Basal bodies and centrioles have identical structures.

Peroxisomes are organelles that are involved in the _____.

breakdown of fatty acids; Peroxisomes break down fatty acids for fuel, and they are involved in the detoxification of alcohol and other harmful substances.

Which cellular organelle is required for photosynthesis to occur in eukaryotic cells?

chloroplast; Chloroplasts contain the green pigment chlorophyll and enzymes and other molecules that function in the photosynthetic production of food.

The _____ is composed of DNA and protein.

chromatin; Chromatin is composed of DNA and protein.

mitochondrion

converts chemical fuel into packets of chemical energy that can power the cell

The structural framework in a cell is the

cytoskeleton; The cytoskeleton is the structural framework in a cell ("cyto" refers to cell and "skeleton" refers to a structural framework).

The primary role of _____ is to bind animal cells together.

desmosomes; The primary role of desmosomes (anchoring junctions) is to bind cells together.

What changes would you expect to see in the liver cells of someone suffering from chronic alcoholism?

increased levels of endoplasmic reticulum activity; The smooth endoplasmic reticulum of liver cells has enzymes that are involved in alcohol metabolism. This organelle is affected in the liver cells of alcoholics.

Bacterial cells are prokaryotic; unlike a typical eukaryotic cell, they _____.

lack a nucleus; The term prokaryotic literally translates as "before nucleus."

Which organelle plays a role in intracellular digestion?

lysosome; The prefix "lyso-" means decomposition.

Which of the following organelles is found only in animal cells and NOT in most plant cells?

lysosome; This organelle is found only in animal cells. Most plant cells do not have a lysosome.

What carries instructions for making proteins from the nucleus into the cytoplasm?

mRNA; The "m" in mRNA stands for "messenger"; mRNA is the messenger that carries genetic instructions from the nucleus to the cytoplasm.

Which of these are hollow rods that shape and support the cell?

microtubules; Microtubules are rods that also play a role in organelle movement.

It is believed that meldonium works on which of the following?

mitochondria

Which of the following is NOT a part of the endomembrane system?

mitochondria; Mitochondria are involved in energy processing and are not members of the endomembrane system.

Where in a cell is ATP made?

mitochondria; ATP is made in mitochondria.

Which of these organelles produces H2O2 as a by-product?

peroxisome; Peroxisomes produce hydrogen peroxide as a by-product of their metabolic processes.

Chloroplasts are found in __________.

plant cells and some protists; Chloroplasts are lens-shaped organelles found in leaves and other green organs of plants and photosynthetic protists.

What is the function of a bacterium's capsule?

protection; A bacterium's capsule has a protective role.

In a bacterium, where are proteins synthesized?

ribosomes; Ribosomes are involved in the manufacture of polypeptides (proteins).

_____ are the sites of protein synthesis.

ribosomes; Ribosomes are the site of protein synthesis.

One of the ways smooth endoplasmic reticulum (ER) differs from rough endoplasmic reticulum is that rough ER is covered by

ribosomes; Ribosomes dock on the rough ER, and proteins are completed inside the rough ER.

The architecture of cell surfaces can be viewed in the most detail using a __________.

scanning electron microscope; The scanning electron microscope uses an electron beam to provide a detailed picture of the outlines of the surface.

smooth ER

site of lipid synthesis

The term resolving power refers to _____.

the clarity of the image in showing two objects as separate; Resolving power is the ability to see two points or objects as separate.

To enter or leave any cell, substances must pass through _____.

the plasma membrane; The plasma membrane defines the boundary of the cell.

Which of these cell junctions form a barrier to the passage of materials?

tight junctions; Tight junctions form a barrier that prevents fluids from moving between cells.

What name is given to the process in which a strand of DNA is used as a template for the manufacture of a strand of pre-mRNA?

transcription; Transcription is the process by which a DNA template is used for the manufacture of several different types of RNA.

cell with only purple and blue organelles

Ancestral cell with nucleus and endomembrane system.

Choose the letter that indicates the organelle that contains most of a cell's DNA.

C; The nucleus contains most of a cell's DNA.

Mitochondrion

Converts chemical fuel into packets of chemical energy (ATP) that can power the cell

Which of these provides the cell with structural support?

D; Microfilaments are a component of the cytoskeleton.

The DNA-containing region of this bacterial cell is indicated by the letter _____.

D; The nucleoid region contains DNA.

By altering atomic movement in cells, scientists are changing what?

Entropy

_____ are surface appendages that allow a bacterium to stick to a surface.

Fimbriae; Fimbriae enable bacterial cells to stick to a surface.

_____ aid in the coordination of the activities of adjacent animal cells.

Gap (communicating) junctions; Gap junctions allow for the passage of material between cells, thus facilitating communication between these cells.

cell with purple and blue organelles with the oxygen-metabolizing bacterium fully inside

Oxygen metabolizing bacterium is fully engulfed in the cell.

cell labeled with photosynthetic prokaryote

Photosynthetic prokaryote begins to be engulfed by ancestral cell.

cell with purple and blue organelles, oxygen-metabolizing bacterium, and the photosynthetic prokaryote fully inside

Photosynthetic prokaryote is fully engulfed, resulting in a eukaryotic cell with organelles; Ancestral prokaryotic cells evolved into the first eukaryotic cells through an inward folding of the plasma membrane and the engulfment and incorporation of other free-living prokaryotic cells. Those engulfed cells functioned as organelles that metabolize oxygen and photosynthesize.

Central Vacuole

Regulates cytoplasm compositions, creates internal pressure,and stores cell compounds

Scientists locate an allosteric site on a bacterial protein. What is this site for?

Regulating the function of the protein.

In which of the following countries would it likely be easiest to obtain meldonium?

Russia

Which of the following is the most likely consequence for a cell lacking functional lysosomes?

The cell becomes crowded with undigested wastes; A lysosome is a membrane-enclosed sac of hydrolytic enzymes that the cell uses to digest macromolecules—in some cases, recycling the cell's own organic material.

One function of the central vacuole in plant cells is facilitating cell growth: the central vacuole absorbs water and increases in size, expanding the volume and size of the plant cell while doing so. Animal cells, however, do not grow by this method. What is an essential difference between animal and plant cells that could explain how a plant cell can withstand this expansion of the central vacuole?

The plant cell wall provides a more rigid structure; The plant cell can use the central vacuole for growth because the cell wall is rigid.

lysosome

breaks down macromolecules using digestive enzymes

Which of the following is NOT an example of an organelle found within an animal cell?

cell wall; Cell walls are found in plant cells, but not in animal cells.

What name is given to the rigid structure, found outside the plasma membrane, that surrounds and supports the bacterial cell?

cell wall; The cell wall is a rigid supporting structure.

Structures found within a eukaryotic cell and performing specific tasks are collectively termed __________.

organelles; These "little organs" perform a variety of functions, including protein production, energy processing, and breakdown of various molecules.

The function of the chloroplast is to _____.

convert light energy to chemical energy; The function of the chloroplast is to convert light energy from the sun to the chemical energy of a glucose molecule.

Which technique allowed scientists to figure out that all cells, and not just muscle cells, contained actin filaments?

electron microscopy; In the 1960s, staining actin filaments and visualizing them with an electron microscope allowed scientists to discover that these structures are present in all cells.

The contractile vacuole __________.

eliminates excess water from the cytoplasm of freshwater protists; It keeps the freshwater protists in osmotic balance.

Which of the following correctly matches an organelle with its function? The __________ functions in __________.

lysosome ... recycling of damaged organelles; Lysosomes contain hydrolytic enzymes that also digest ingested food.

The cells of a person with adrenoleukodystrophy (ALD) swell with a buildup of fatty acids. In other words, fatty acids are not being broken down. Which organelle is most likely failing to function correctly?

lysosome; This organelle functions to remove unwanted or unneeded material from the cell.

Which of the following organelles breaks down worn-out organelles?

lysosomes; Lysosomes contain digestive enzymes and break down worn-out organelles.

RNA processing converts the RNA transcript into _____.

mRNA; The editing of the RNA transcript produces mRNA.

The internal skeleton of a cell is composed of _____.

microtubules, intermediate filaments, and microfilaments; These three types of fibers make up the cytoskeleton.

The cilia and flagella of eukaryotic cells are composed of _____.

microtubules; Eukaryotic cilia and flagella are composed of microtubules.

When elongated, tube-shaped cells from the lining of the intestine are treated with a certain chemical, the cells sag and become rounded. The internal structures disrupted by this chemical are probably __________.

microtubules; Microtubules are cytoskeletal components, and the shape of a cell is determined by its cytoskeleton.

Which of these organelles carries out cellular respiration?

mitochondrion; Mitochondria convert the chemical energy of organic molecules to chemical energy in the form of ATP.

Where is a bacterial cell's DNA found?

nucleoid region; Bacteria lack a nucleus; their DNA is found in the nucleoid region.

Ribosomal subunits are manufactured by the _____.

nucleolus; Ribosomes are manufactured by the nucleolus.

Where is the genetic information of the cell stored?

nucleus; DNA is the genetic information of the cell, and it is stored in the nucleus.

Digestive cells produce and secrete many enzymes that break down ingested food. These cells have a large number of ribosomes __________.

on the rough endoplasmic reticulum; The rough endoplasmic reticulum is responsible for producing proteins that will be inserted into membranes, packaged in certain organelles, or exported from the cell.

You have identified a new organism. It has ribosomes, plasmodesmata, and cell walls made of cellulose. This new organism is most likely a(n) __________.

plant; Plant cells have cell walls that are made of cellulose and plasmodesmata, which are cytoplasmic channels that connect adjacent cells.

The _____ is the bacterial structure that acts as a selective barrier, allowing nutrients to enter the cell and wastes to leave the cell.

plasma membrane; The plasma membrane is selectively permeable.

The _____ is a selective barrier, regulating the passage of material into and out of the cell.

plasma membrane; The plasma membrane regulates the passage of material into and out of the cell.

What structure acts as a selective barrier, regulating the traffic of materials into and out of the cell?

plasma membrane; The plasma membrane surrounds the cell and regulates the movement of materials into and out of the cell.

Which of these manufactures cellular membranes by adding membrane proteins and phospholipids to its own membrane?

rough endoplasmic reticulum; As membrane proteins grow from ribosomes on rough ER, the proteins are embedded into the rough ER membrane.

Pancreatic cells produce large amounts of protein. About how many ribosomes would you expect there to be in a pancreatic cell?

several million; There are several million ribosomes in cells, such as the cells in the pancreas that produce digestive enzymes

Where are lipids made in the cell?

smooth endoplasmic reticulum (ER); The smooth ER makes lipids.

Where is calcium stored?

smooth endoplasmic reticulum; In addition to storing calcium, the smooth ER also plays a role in detoxification and lipid synthesis.

nucleus

stores the genetic information of the cell

Plant Cell Wall

strong, protective structure made from cellulose fibrils

In eukaryotic cells the first step in protein synthesis is the _____.

transferring of information from DNA to messenger RNA; Transcription is the first of the two main steps of protein synthesis.

What name is given to the process in which the information encoded in a strand of mRNA is used to construct a protein?

translation; Translation is the process by which information encoded in RNA is used to manufacture a polypeptide.

If you wished to clearly observe the organelles inside of a white blood cell, which type of microscope would you choose?

transmission electron microscope; This type of microscope allows you to view internal structures of living cells.

The NBA decides to look into the use of meldonium in the league following the same protocol as the WADA. Which of the following will be randomly tested?

urine samples

Which of the following clues would tell you whether a cell is prokaryotic or eukaryotic?

whether or not the cell is partitioned into compartments by internal membranes; Prokaryotic cells lack any internal membranous compartmentalization whereas eukaryotic cells have membrane-bound organelles.

Which of the following is part of the endomembrane system?

Golgi apparatus; The endomembrane system includes the ER, the Golgi apparatus, lysosomes, and vesicles. It manufactures, processes, and transports lipids and proteins. The Golgi apparatus processes and packages proteins.