Mastering Biology 4

Which statements are true for chloroplasts? Select the three that apply

-They contain the green pigment chlorophyll. -They are the sites of reactions that convert solar energy into chemical energy. -They have membranous sacs called thylakoids that are surrounded by a fluid called stroma.

Proteins that are secreted from a eukaryotic cell must first travel through the endomembrane system.

1. Protein synthesis 2. ER 3. cis Golgi cisternae 4. medial Golgi cisternae 5. trans Golgi cisternae 6. plasma membrane

_____ is/are identical in structure to centrioles. Mitochondria Nuclear envelopes Basal bodies Microfilaments Chromatin

Basal Bodies

Which molecules do not normally cross the nuclear membrane? DNA Nucleotide triphosphates Proteins mRNA

DNA

The primary role of _____ is to bind animal cells together. plasmodesmata gap (communicating) junctions desmosomes tight junctions the cytoskeleton

Desmosomes

Pancreatic cells, which secrete a large amount of digestive enzymes, are labeled with radioactive leucine and then chased for several hours with nonradioactive leucine. Photographic emulsions are prepared at different times during the chase. Where would the black spots appear on an emulsion prepared 3 hours after the pulse? Secretory vesicles Exterior of the cell Rough ER Golgi apparatus

Exterior of the Cell

True or false? Large proteins containing a nuclear localization signal (NLS) bind to the nuclear pore and enter the nucleus without any expenditure of energy.

False

True or false? Proteins produced during the "chase" phase of a pulse-chase experiment are labeled with radioactive material.

False

_____ are surface appendages that allow a bacterium to stick to a surface. Fimbriae Mitochondria Ribosomes Flagella Cell walls

Fimbriae

_____ aid in the coordination of the activities of adjacent animal cells. Desmosomes Gap (communicating) junctions Tight junctions Keratin fibers Plasmodesmata

Gap (communicating) junctions

What is the first step in a pulse-chase experiment? Incubating cells with an unlabeled molecule Incubating cells with a labeled molecule Examining cells for the location of the labeled molecules Preparing cells for electron microscopy

Incubating cells with a labeled molecule

Which of the following proteins are synthesized by bound ribosomes? Select all that apply. actin DNA polymerase insulin ER protein ribosomal protein lysosomal enzyme

Insulin, ER protein, Lysosomal enzyme

Which of these are hollow rods that shape and support the cell? plasma membrane microtubules microfilaments peroxisomes chloroplasts

Microtubules

What scientific hypotheses can be tested by a pulse-chase experiment? Movement of molecules through a cell over time Solubility of a molecule Molecular zip code of a protein The steady-state amount of protein in a cell

Movement of molecules through a cell over time

Nucleoplasmin is a nuclear protein. This protein was divided into two segments and linked to the same large cytoplasmic protein, generating two fusion proteins. After injecting these fusion proteins into a cell, one of the proteins was found in the nucleus and the other in the cytoplasm. Which of the following conclusions can be drawn from these results? A: One of the fusion proteins entered the nucleus by passive transport. B: The cytoplasmic protein contains a nuclear localization signal. C: Only one of the two fusion proteins possesses a nuclear localization signal. D: Nucleoplasmin does not have a nuclear localization signal.

Only one of the two fusion proteins possesses a nuclear localization signal

A small protein (molecular weight = 25,000 daltons) is injected into a cell and observed in the nucleus a short time later. What type of transport has taken place?

Passive Transport

Which of these organelles produces H2O2 as a by-product? nucleus mitochondrion flagellum centrioles peroxisome

Peroxisome

Drag each cell structure to the appropriate bin. If a structure is found in both plant cells and animal cells, drag it to the "both" bin. A: Chloroplasts B: Cellulose Cell Wall C: Central Vacuole D: Centriole E: Plasma membrane F: Cytoskeleton G: Mitochondria H: Golgi Apparatus I: ER J: Nucleus

Plant Cells: A, B, C Animal Cells: D Both: E, F, G, H, I, J,

The _____ is a selective barrier, regulating the passage of material into and out of the cell. nuclear envelope chloroplast nucleus plasma membrane lysosome

Plasma Membrane

Two fundamental types of cells are known to exist in nature: prokaryotic cells and eukaryotic cells (like the one shown in the Tour of an Animal Cell animation). Both prokaryotic and eukaryotic cells carry out all of the processes necessary for life, but they differ in some important ways. In this activity, you will identify which cell structures are found only in prokaryotic cells, only in eukaryotic cells, or in both types of cells.

Prokaryotic: nucleoid Eukaryotic: lysosome, nucleolus, mitochondria Both: plasma membrane, flagella, ribosomes

_____ are the sites of protein synthesis. Ribosomes Golgi apparatuses Microfilaments Peroxisomes Mitochondria

Ribosomes

Which of these manufactures cellular membranes by adding membrane proteins and phospholipids to its own membrane? lysosomes ribosomes nucleolus Golgi apparatus rough endoplasmic reticulum

Rough ER

What path does a protein in the secretory pathway take, starting from its site of synthesis? Plasma membrane, secretory vesicles, Golgi apparatus, rough ER Golgi apparatus, rough ER, secretory vesicles, plasma membrane Rough ER, secretory vesicles, Golgi apparatus, plasma membrane Rough ER, Golgi apparatus, secretory vesicles, plasma membrane

Rough ER, Golgi, Secretory Vesicles, Plasma membrane

Where is calcium stored? centrioles mitochondria microtubules rough endoplasmic reticulum smooth endoplasmic reticulum

Smooth ER

The various parts of the endomembrane system serve different functions in the cell. In this activity, you will identify the roles of each part of the endomembrane system. A: Lipid Synthesis B: Calcium Ion Storage C: Poison Detoxication D: Protein Synthesis E: Protein Modification and Sorting F: Cisternal Maturation G: Macromolecule digestion H: Autophagy

Smooth ER: A, B, C Rough ER: D Golgi Apparatus: E, F Lysosomes: G, H

During a pulse-chase experiment, photographic emulsions were prepared at different times during the chase, and radioactive spots were detected at the following times and locations: 5 minutes: rough ER; 10 minutes: Golgi apparatus; 40 minutes: endosomes; 70 minutes: lysosomes; 140 minutes: lysosomes. Which of the following conclusions can be drawn from these results? The proteins were secreted. The proteins did not travel through the Golgi apparatus. The final destination of the proteins was the lysosome. The proteins traveled from lysosomes to endosomes.

The final destination of the proteins was the lysosome

Which of the following statements about the nuclear envelope is false? A: Molecules pass into and out of the nucleus through nuclear pores. B: Nuclear pores are made up of a group of proteins that are collectively called the nuclear pore complex. C: The nuclear envelope is continuous with the Golgi apparatus. D: The nuclear envelope is composed of two lipid bilayers.

The nuclear envelope is continuous with the Golgi Apparatus

Which of these cell junctions form a barrier to the passage of materials? plasmodesmata desmosomes (anchoring junctions) gap (communicating) junctions keratin fibers tight junctions

Tight Junctions

In experiments to test whether a protein can enter the nucleus, why would proteins be labeled with fluorescent molecules? To target the proteins to the nucleus To give the protein molecules energy To make the proteins easy to see To make the proteins bigger

To make the proteins easy to see

What name is given to the rigid structure, found outside the plasma membrane, that surrounds and supports the bacterial cell? capsule pili cell wall flagella nucleoid region

cell wall

The _____ is composed of DNA and protein. chromatin flagellum ribosome mitochondrion centriole

chromatin

Many cell organelles, most notably the nucleus, are anchored by ____________ which are assembled from a diverse class of proteins

intermediate filaments

The only cytoskeletal fibers not associated with intracellular movement or whole cell locomotion are the _____________.

intermediate filaments

Which organelle plays a role in intracellular digestion? lysosome plasmodesma ribosome chloroplast Golgi apparatus

lysosome

During muscle contractions, myosin motor proteins move across tracks of ________________.

microfilaments

The extension of pseudopodia in amoeba is due to the regulated assembly and destruction of ____________.

microfilaments

Centrosomes are sites where protein dimers assemble into _____________.

microtubules

In eukaryotic flagella, the fibers that slide past one another due to the activity of dynein proteins are ____________.

microtubules

The cilia and flagella of eukaryotic cells are composed of _____. microtubules microfilaments tonofilaments intermediate filaments pili

microtubules

Which of these organelles carries out cellular respiration? ribosomes smooth endoplasmic reticulum mitochondrion chromatin nucleolus

mitochondrion

Where is a bacterial cell's DNA found? ribosomes nucleus peroxisome nucleoid region capsule

nucleoid region

Ribosomal subunits are manufactured by the _____. nucleolus rough endoplasmic reticulum peroxisome lysosome smooth endoplasmic reticulum

nucleolus

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 nucleoid region ribosome pili cell wall

plasma membrane

What is the function of a bacterium's capsule? adhesion protein synthesis propulsion DNA storage protection

protection

In a bacterium, where are proteins synthesized? ribosomes nucleus peroxisome nucleoid region capsule

ribosomes

Beginning within the nucleus, the first step leading to the synthesis of a polypeptide is _____.

tranferring of information from DNA to messenger RNA