BI 125 -- Exam #2

Which component is part of the extracellular matrix? A) A B) B C) C D) D E) E

A)

Mammalian blood contain the equivalent of 0.15 M NaCl. Seawater contains the equivalent of 0.45 M NaCl. What will happen if red blood cells are transferred to seawater? A) Water will leave the cells, causing them to shrivel and collapse B) The blood cells will expend ATP for active transport of NaCl into the cytoplasm C) The blood cells will take up water, swell, and eventually burst D) NaCl will passively diffuse into the red blood cells

A) Water will leave the cells causing them to shrivel and collapse

Microfilaments are composed of which of the following proteins? A) actin B) fibronectin C) keratin D) tubulin

A) actin

The movement of a substance across a biological membrane against its concentration gradient with the help of energy input is which of the following? A) active transport B) osmosis C) facilitated diffusion D) diffusion

A) active transport

In plant cells, _______ may contain organic nutrients, pigments, and poisons A) central vacuoles B) chloroplasts C) mitochondria D) lysosomes

A) central vacuoles

What type of reaction is depicted in the chemical reaction below? glycerol + 3 fatty acids --> triglyceride + 3 water molecules A) dehydration reaction B) denaturation C) hydrolysis D) hydrogenation

A) dehydration reaction

What type of covalent bond between amino acid side chains (R groups) functions in maintaining a polypeptide's specific three-dimensional shape? A) disulfide bond B) ionic bond C) hydrogen bond D) hydrophobic interaction

A) disulfide bond

In a plant cell, DNA may be found A) in the nucleus, mitochondria and chloroplasts B) only in the nucleus and mitochondria C) only in the nucleus D) only in the nucleus and chloroplasts

A) in the nucleus, mitochondria and chloroplasts

Eukaryotic cells require which of the following to form cilia or flagella? A) microtubules B) intermediate filaments C) microfilaments D) actin

A) microtubules

Motor proteins utilize ATP and travel along what cell structure to move cargo from one part of the cell to another part of the cell? A) microtubules B) actin filaments C) intermediate filaments D) smooth endoplasmic reticulum

A) microtubules

Which structure is common to plant and animal cells? A) mitochondria B) lysosome C) chloroplast D) central vacuole

A) mitochondria

The membrane activity most nearly opposite to exocytosis is A) phagocytosis B) active transport C) facilitated diffusion D) osmosis

A) phagocytosis

A glycerol with two fatty acids and a phosphate group attached is referred to as a A) phospholipid B) nucleotide C) steroid D) triglyceride

A) phospholipid

Which level of protein structure is made up of a unique sequence and is determined by genetic information? A) primary B) secondary C) tertiary D) quaternary

A) primary

All of the following are functions of membrane proteins except A) protein synthesis B) intercellular joining C) cell-cell recognition D) transport E) signal transduction

A) protein synthesis

Which of the following describes the function of the nucleolus? A) synthesizes ribosomal RNA and assembles ribosome subunits B) provides the structural support for the nuclear membrane C) the gatekeeper of the nucleus facilitating communication between the cytoplasm and the nucleus D) a region in a prokaryotic cell that contains the chromosome

A) synthesizes ribosomal RNA and assembles ribosome subunits

Which component is a glycolipid? A) A B) B C) C D) D E) E

B)

Which of the following are nitrogenous bases of the pyrimidine type? A) adenine and thymine B) cytosine and uracil C) guanine and cytosine D) ribose and deoxyribose

B) cytosine and uracil

Intestinal cells have a high surface area to volume ration due to these small projections from the cell A) cilia B) microvilli C) flagella D) cytoskeleton

B) microvilli

Which component of the nucleus is made of intermediate filaments? A) nuclear membrane B) nuclear lamina C) nuclear pores D) nucleolus

B) nuclear lamina

The extracellular matrix A) is a matrix of integral membrane proteins that are used in facilitated diffusion B) surrounds animal cells providing support, cushioning, and signaling for cells C) surrounds plant cells providing a rigid structure of support D) includes proteins and carbohydrates that are made outside the cell

B) surrounds animal cells providing support, cushioning, and signaling for cells

Suppose that you were asked to identify a cell by looking at it through the light microscope. After viewing the specimen, you note that the cell has a cell wall, no nucleus, and is roughly spherical in shape. You conclude: A) the cell is a eukaryotic cell and most likely is from an animal B) the cell is a prokaryotic cell C) the cell is a eukaryotic cell and most likely is from a plant D) the cell is a eukaryotic cell but could be either a plant or animal cell based on the given information

B) the cell is a prokaryotic cell

What structures move proteins from the ER to the golgi apparatus? A) lysosomes B) transport vesicles C) ribosomes D) mitochondria

B) transport vesicles

If one strand of a DNA molecule has the sequence of bases 5' ATTGCA3', the other complementary strand would have the sequence A) 3'UAACGU5' B) 5'UGCAAU3' C) 3'TAACGT5' D) 5' TAACGT3'

C)

Nucleotides are made up of what parts? A) three fatty acids attached to a glycerol backbone B) a nitrogenous base and a pentose sugar C) a nitrogenous base, pentose sugar, and a phosphate group D) two fatty acids and a phosphate group attached to a glycerol backbone E) a pentose sugar and a purine or pyrimidine

C)

Which of the following statements does not accurately describe a difference between prokaryotic and eukaryotic cells? A) Eukaryotic cells are typically larger than prokaryotic cells B) Eukaryotic cells have a nucleus while prokaryotic cells have a nucleoid C) Eukaryotic cells do not contain chloroplasts while prokaryotic cells do D) Eukaryotic cells have membrane bound organelles while prokaryotic do not

C)

Which of the following is true of starch? A) It is composed of glucose molecules linked by peptide bonds B) It is a structural component of plant cell walls C) It is an energy-storage molecule for plants D) It is an energy-storage molecule for animals

C) It is an energy -storage molecule for plants

The endomembrane systems consists of all of the following except? A) nuclear envelope B) endoplasmic reticulum C) mitochondria D) golgi apparatus E) transport vesicles

C) mitochondria

Which of the following is an incorrect match? A) ribosomes - protein synthesis B) lysosomes - protein digestion C) mitochondria - protein recycling D) golgi apparatus - protein alteration

C) mitochondria - protein recycling

All of the following molecules are part of animal cell membrane except A) phospholipids B) cholesterol C) nucleic acids D) proteins E) carbohydrates

C) nucleic acids

Ribosomes are composed of what two types of macromolecules? A) proteins and DNA B) proteins and lipids C) proteins and RNA D) RNA and lipids

C) proteins and RNA

A molecule of oxygen crosses a plasma membrane by A) osmosis B) phagocytosis C) simple diffusion D) active transport

C) simple diffusion

The ovaries and testes produce a large amount of steroid hormones. Which of the following structures is primarily involved in this process and therefore abundant in the cells of these organs? A) rough ER B) golgi apparatus C) smooth ER D) lysosomes

C) smooth ER

(use figure on test 16-18) Which component is the peripheral membrane protein? A) A B) B C) C D) D E) E

D)

Cells are so small because A) they need to prevent too many things coming into the cell B) they need to be seen with a microscope C) the cytoskeleton is not strong enough to support larger cells D) they need a surface area of sufficient size compared to their volume to support enough nutrient uptake and waster removal for the cells to survive

D)

Facilitated diffusion A) moves molecules from high concentration to low concentration B) requires the use of integral membrane proteins C) takes place without a source of energy D) All of the above are true

D) All of the above are true

Osmosis is A) the movement of water from an area of high concentration of water to an area of low concentration of water B) the passive transport of solute down their concentration gradient C) the movement of water from an area of low solute concentration to an area of high solute concentration D) Both A and C are correct E) A, B, C are correct

D) Both A and C are correct

Which of the following factors would tend to increase membrane fluidity? A) a lower temperature B) a greater proportion of saturated phospholipids C) a relatively high protein content in the membrane D) a greater proportion of unsaturated phospholipids

D) a greater proportion of unsaturated phospholipids

Chloroplasts and mitochondria are similar in that they both ________ A) are involved in energy conversion B) contain ribosomes C) have a second, interior membrane D) all of the above choices are correct

D) all of the above choices are correct

Amphipathic molecules are A) hydrophobic B) hydrophilic C) water molecules D) both hydrophilic and hydrophobic

D) both hydrophilic and hydrophobic

Plasmodesmata in plant cells are most similar in function to which of the following structures in animal cells? A) peroxisomes B) tight junctions C) desmosomes D) gap junctions

D) gap junctions

The interior of the phospholipid bilayer is A) composed of phosphates B) water C) hydrophilic D) hydrophobic E) composed of carbohydrates

D) hydrophobic

A protist that contains contractile vacuoles to aid in osmoregulation most likely lives _______ A) on land B) in the ocean C) within the cells of another organism D) in fresh water

D) in fresh water

Which organelle is the primary site of ATP synthesis in eukaryotic cells? A) golgi apparatus B) lysosome C) rough endoplasmic reticulum D) mitochondira

D) mitochondria

Which of the following is a correct match? A) exocytosis - substances taken into the cell B) endocytosis - substances secreted from the cell C) pinocytosis - liquids secreted from the cell D) phagocytosis - large particles taken into the cell

D) phagocytosis

Which structures in the cell synthesize proteins that will be exported or secreted from the cell A) free ribosomes B) golgi apparatus C) plasmodesmata D) rough ER

D) rough ER

What is not a role for the lysosomes in the cell? A) digestion of macromolecules B) recycler of organic material C) destroys bacteria engulfed by macrophages D) warehouse for storing, sorting, and shipping

D) warehouse for storing, sorting, and shipping

Which of the following characterizes the sodium-potassium pump? A) Potassium ions are pumped into a cell against their concentration gradient B) Sodium ions are pumped out of a cell against their concentration gradient C) An integral membrane protein undergoes conformational change D) A and B E) A, B, and C

E) A, B, and C

According to the fluid mosaic of cell membranes, which of the following is a true statement about membrane phospholipids A) They frequently flip-flop from one side of the membrane to the other B) They have hydrophilic tails in the inferior of the membrane C) They are free to depart from the membrane and dissolve in the surrounding solution D) They occur in an uninterrupted bilayer, with membrane proteins restricted to the surface of the membrane E) They can move laterally along the plane of the membrane

E) They can move laterally along the plane of the membrane

Phospholipids containing unsaturated fats would A) make the membrane more fluid B) create more hydrophobic interactions with molecules of the same type C) make the membrane less fluid D) create less hydrophobic interactions with molecules of the same type E) both A and D are correct

E) both A and D are correct