Chapter 3

Watch this video (http://openstaxcollege.org// ribosome) to learn about ribosomes. The ribosome binds to the mRNA molecule to start translation of its code into a protein. What happens to the small and large ribosomal subunits at the end of translation?

Because they are embedded within the membrane, ion channels are examples of ________. a. receptor proteins b. integral proteins c. peripheral proteins d. glycoproteins

The diffusion of substances within a solution tends to move those substances ________ their ________ gradient. a. up; electrical b. up; electrochemical c. down; pressure d. down; concentration

Ion pumps and phagocytosis are both examples of ________. a. endocytosis b. passive transport c. active transport d. facilitated diffusion

Choose the answer that best completes the following analogy: Diffusion is to ________ as endocytosis is to ________. a. filtration; phagocytosis b. osmosis; pinocytosis c. solutes; fluid d. gradient; chemical energy

Choose the term that best completes the following analogy: Cytoplasm is to cytosol as a swimming pool containing chlorine and flotation toys is to ________. a. the walls of the pool b. the chlorine c. the flotation toys d. the water

The rough ER has its name due to what associated structures? a. Golgi apparatus b. ribosomes C. lysosomes d. proteins

Which of the following is a function of the rough ER? a. production of proteins b. detoxification of certain substances C. Synthesis of steroid hormones d. regulation of intracellular calcium concentration

Which of the following is a feature common to all three components of the cytoskeleton? a. They all serve to scaffold the organelles within the cell. b. They are all characterized by roughly the same diameter. c. They are all polymers of protein subunits. d. They all help the cell resist compression and tension.

Which of the following organelles produces large quantities of ATP when both glucose and oxygen are available to the cell? a. mitochondria b. peroxisomes C. lysosomes d. \(\mathrm{ER}\)

The nucleus and mitochondria share which of the following features? a. protein-lined membrane pores b. a double cell membrane c. the synthesis of ribosomes d. the production of cellular energy

Which of the following structures could be found within the nucleolus? a. chromatin b. histones C. ribosomes d. nucleosomes

Which of the following sequences on a DNA molecule would be complementary to GCTTATAT? a. TAGGCGCG b. ATCCGCGC c. \(\quad\) CGAATATA d. TGCCTCTC

Place the following structures in order from least to most complex organization: chromatin, nucleosome, DNA, chromosome a. DNA, nucleosome, chromatin, chromosome b. nucleosome, DNA, chromosome, chromatin c. DNA, chromatin, nucleosome, chromosome d. nucleosome, chromatin, DNA, chromosome

Which of the following is part of the elongation step of DNA synthesis? a. pulling apart the two DNA strands b. attaching complementary nucleotides to the template strand C. untwisting the DNA helix d. none of the above

Which of the following is not a difference between DNA and RNA? a. DNA contains thymine whereas RNA contains uracil b. DNA contains deoxyribose and RNA contains ribose C. DNA contains alternating sugar-phosphate molecules whereas RNA does not contain sugars d. RNA is single stranded and DNA is double stranded

Transcription and translation take place in the ________ and ________, respectively. a. nucleus; cytoplasm b. nucleolus; nucleus c. nucleolus; cytoplasm d. cytoplasm; nucleus

How many "letters" of an RNA molecule, in sequence, does it take to provide the code for a single amino acid? a. 1 b. 2 c. 3 d. 4

Which of the following is not made out of RNA? a. the carriers that shuffle amino acids to a growing polypeptide strand b. the ribosome C. the messenger molecule that provides the code for protein synthesis d. the intron

Which of the following phases is characterized by preparation for DNA synthesis? a. \(\mathrm{G}_{0}\) b. \(\mathrm{G}_{1}\) C. \(\mathrm{G}_{2}\) d. \(\mathrm{S}\)

A mutation in the gene for a cyclin protein might result in which of the following? a. a cell with additional genetic material than normal b. cancer c. a cell with less genetic material than normal d. any of the above

What is a primary function of tumor suppressor genes? a. stop all cells from dividing b. stop certain cells from dividing c. help oncogenes produce oncoproteins d. allow the cell to skip certain phases of the cell cycle

Which type of stem cell gives rise to red and white blood cells? a. endothelial b. epithelial C. hematopoietic d. mesenchymal

What multipotent stem cells from children sometimes banked by parents? a. fetal stem cells b. embryonic stem cells C. cells from the umbilical cord and from baby teeth d. hematopoietic stem cells from red and white blood cells

What materials can easily diffuse through the lipid bilayer, and why?

Why is receptor-mediated endocytosis said to be more selective than phagocytosis or pinocytosis?

What do osmosis, diffusion, filtration, and the movement of ions away from like charge all have in common? In what way do they differ?

Explain why the structure of the ER, mitochondria, and Golgi apparatus assist their respective functions.

Compare and contrast lysosomes with peroxisomes: name at least two similarities and one difference.

Explain in your own words why DNA replication is said to be "semiconservative"?

Why is it important that DNA replication take place before cell division? What would happen if cell division of a body cell took place without DNA replication, or when DNA replication was incomplete?

Briefly explain the similarities between transcription and DNA replication.

Contrast transcription and translation. Name at least three differences between the two processes.

What would happen if anaphase proceeded even though the sister chromatids were not properly attached to their respective microtubules and lined up at the metaphase plate?

What are cyclins and cyclin-dependent kinases, and how do they interact?

Explain how a transcription factor ultimately determines whether or not a protein will be present in a given cell?

Discuss two reasons why the therapeutic use of embryonic stem cells can present a problem.