Chapter 4 test questions

Bacterial ribosomes: a) have a sedimentation rate of 70S b) are made up of 30S and 40S subunits c) have a sedimentation rate of 80S d) are made up of 50S and 30S subunits

A

A typical bacterial cell has a salt concentration of about 1%. If the cell is placed in a solution containing 10% salt, the net flow of water will be _____. a) out of the cell b) into the cell c) equally in and out of the cell d) none of the above since water doesn't cross bacterial cell membranes

A

Osmosis most directly involves: a) water moving down a concentration gradient b) organic molecules crossing a membrane c) energy being expended to import large molecules into the cell d) sugars and salts moving down their concentration gradient

A

Removal of the cell wall of a Gram positive bacteria results in the formation of a _____. a) protoplast b) spheroplast c) periplast d) polyplast

A

Some bacteria can transfer DNA to another cell using: a) conjugation pili b) fimbriae c) axial filaments d) lophotrichous flagella

A

Which is the correct ordering of cell wall components starting from outside the cell and going inward? a) In gram positive bacteria: peptidoglycan, cell membrane b) In gram negative bacteria: peptidoglycan, lipopolysaccharide, periplasmic space, outer membrane, cell membrane c) In acid fast bacteria: peptidoglycan, lipid layer, cell membrane d) In gram negative bacteria: peptidoglycan, periplasmic space, lipid membrane

A

Which of the following is true about bacteria? a) All bacteria cells are smaller than 100 micrometers in diameter. b) The cell wall controls the movement of small molecules into and out of the cell. c) Gram negative bacteria become protoplasts when their cell wall is digested away. d) Bacterial endospores are reproductive structures.

A

Which of the following statements about cell walls is false? a) All bacterial cell walls contain teichoic acids. b) Plants and fungi have cell walls. c) Bacteria which have lost their cell wall are known as L-forms. d) Algal protists have cell walls.

A

Which of the following statements about outer membranes is true? a) It contains an endotoxin (lipopolysaccharide) which is responsible for fever and potentially serious complications in human infections. b) It prevents the cell from lysing when fluids flow into the cell. c) Treatment with antibiotics which kill the bacteria will reduce the concentration of endotoxin. d) It is a space that is very active in cell metabolism

A

Which of the following statements about the prokaryotic cells surface-to-volume ratio is false? a) Because of their small size, bacteria have a small surface-to-volume ratio b) Eukaryotes have surface-to-volume ratio that is only 1/10 that of prokaryotes c) The prokaryotes surface-to-volume ratio means that nutrients can easily and quickly reach all parts of the cell as no internal part of the cell is very far from the surface. d) A bacteria with a surface area of about 12 microns squared and a volume of 4 cubic microns has a surface-to-volume ratio of 3:1

A

Which of the following statements is false? a) All bacteria are capable of forming capsules. b) The chemical composition of each capsule is unique to a particular strain of bacteria. c) Slime layers are usually thinner than capsules. d) A slime layer protects bacteria against drying and helps trap nutrients near a cell.

A

[Insert Fig. 4.3 - Remove all leaders lines and text] 58) This type of cell is a _____. a) prokaryote. b) eukaryote. c) Both A and B are correct d) Neither A nor B are correct

A

_____ occurs when bacteria differ widely in form. a) Pleomorphism b) Polymorphism c) Anamorphism d) Telomorphism

A

Bacteria move by means of: a) cilia b) flagella c) fimbriae d) pili

B

Bacteria with flagella all over their surface are said to be: a) monotrichous b) peritrichous c) amphitrichous d) lophotrichous

B

During diffusion, molecules _____. a) move from hotter areas to cooler areas b) move from areas of higher concentration to areas of lower concentration c) move from areas of lower concentration to areas of higher concentration d) expend energy to more around

B

Endocytosis: a) releases material in the form of phagosomes. b) is the process of taking materials into the cell. c) directs material to the endoplasmic reticulum. d) uses simple diffusion move material across the plasma membrane.

B

Endospores are typically found in the genus: a) Streptococcus b) Clostridium c) Mycobacterium d) Staphylococci

B

Endospores are usually induced to form when: a) temperatures rise b) certain nutrient are depleted c) radiation is detected d) water is lost from the cell

B

Extrachromosomal DNA in prokaryotic cells can be found in the form of _____. a) chromosomes b) plasmids c) mitochondria d) chloroplasts

B

Peptidoglycan makes up more than 50% of a ________ cell wall. a) Gram negative b) Gram positive c) Gram variable d) acid-fast

B

Prokaryotic cells divide by _____. a) mitosis b) binary fission c) meiosis d) mitosis asexually and meiosis sexually

B

The Fluid-mosaic model describes the structure of _____. a) cell walls b) cell membranes d) capsules d) endosymbiotic relationships

B

The _____ portion of the cell membrane functions as a barrier while the ______ portion provides specific functions, including pumps, receptors, adhesion, etc. a) carbohydrate; nucleic acid b) lipid; protein c) lipid; carbohydrate d) nucleic acid; lipid

B

The charged, phosphate end of a membrane phospholipid is: a) water-fearing b) hydrophilic c) hydrophobic d) none of the above

B

The flagellar arrangement represented in this image is_____. a) monotrichous b) peritrichous c) amphitrichous d) lophotrichous

B

The shape of a bacterial cell is determined (and maintained) by the _____. a) cell membrane b) cell wall c) capsule d) slime layer

B

The most important structural component of bacterial cell walls is _____. a) teichoic acid b) lipotechoic acid c) peptidoglycan d) glutamic acid

C

What is the function of gas-filled vacuoles in aquatic photosynthetic bacteria? a) transducers to detect chemicals and signal the cells to respond b) regulate the depth at which they float by changing amount of gas in vacuoles c) change the handedness of the helix in which the bacteria is moving d) allows the bacteria to respond to magnetic fields

B

Which of the following cellular structures are found only in prokaryotic cells? a) endoplasmic reticulum b) pili c) nucleolus d) lysosomes

B

Which of the following statements about motility is false? a) Chemotaxis is the movement of bacteria toward or away from a chemical. b) Pseudopodia are associated with fungi. c) Bacteria use helical flagellar movements to orient towards external signals. d) Pseudopodia are temporary projections of cytoplasm.

B

Coccus-shaped cells which divide along two planes will produce cells arranged into _____. a) diplococci b) streptococci c) tetrads d) staphylococci

C

In bacteria, the cell membrane functions in the all of the following ways except: a) regulate movement of materials into and out of the cell b) synthesizes cell wall components c) serve as the site for protein synthesis d) assists with DNA replication

C

Lysozyme, found in human tears, controls the growth of bacteria by _____. a) fusing with vacuoles b) containing multiple kinds of digestive enzymes c) digesting peptidoglycan d) preventing peptidoglycan synthesis

C

Mitochondria: a) are responsible for converting sunlight to chemical energy b) are present only in photosynthetic organisms c) have a double membrane d) are responsible for protein synthesis

C

The cytoskeleton consists of _____. a) microfilaments and sterols b) microtubules and proteins c) microfilaments and microtubules d) sterols and proteins

C

The outer (cell) membrane component of the cell wall _____. a) is found only in Gram positive bacteria b) is made primarily of peptidoglycan c) contains lipopolysaccharrides d) is primarily a reproductive structure

C

The rough endoplasmic reticulum appears rough because of _____. a) sterols in its membrane b) fats and sugars on its surface c) multiple ribosomes on its surface d) proteins in the lumen of the ER

C

This structure can be Gram positive or Gram negative. a) A b) B c) C d) D

C

Which bacterial genus normally lacks a cell wall? a) Mycobacterium b) Streptococcus c) Mycoplasma d) Bacillus

C

Which of the following is not a common bacterial shape? a) Spirochete b) Coccus c) Disc d) Bacillus

C

Which of the following statements about the endosymbiotic hypothesis is false? a) Eukaryotic cells have both 70S and 80S ribosomes. b) Mitochondria have their own DNA. c) When removed from cells, mitochondria continue to grow and divide. d) Mitochondria are about the same size as prokaryotic cells.

C

Which of these statements about eukaryotic cell division is false? a) the nuclei of eukaryotic cells divide via the process of mitosis b) haploids are cells that receive only one chromosome from each pair of chromosomes c) a single round of mitosis results in the production of four haploid cells d) during mitosis the nuclear envelope breaks apart and the spindle apparatus forms

C

While division in one plane produces cells in pairs, what does random division produce? a) Sarcinae b) Eight cells arranged in a cube c) Grapelike clusters (staphylo-) d) Four cells arranged in a cube

C

A charged molecule which moves down its concentration gradient and across a pore in a cell membrane without energy being expended by the cell is experiencing _____. a) simple diffusion b) osmosis c) active transport d) facilitated diffusion

D

A small comma shaped bacteria is described as being a ________. a) spirochete b) bacillus c) spirillum d) vibrio

D

Attachment pili do all of the following except, a) help bacteria adhere to surfaces b) allow bacteria to form a pellicle at the air-water interface of a broth culture c) clump blood cells in a process called hemagglutination d) prevent the pathogenicity of certain bacteria

D

Bacilli produce fewer arrangements than cocci because _____. a) cocci are smaller than bacilli b) bacilli only reproduce asexually c) bacilli divide along several different planes while cocci divide along a single plane d) cocci divide along several different planes while bacilli divide along a single plane

D

Eukaryotic cells add rigidity to their plasma membrane by including what component in the membrane? a) Protein b) Lipids c) Sugars d) Sterols

D

Genetic information in bacteria is: a) found in the nucleus b) found only in RNA c) found in DNA condensed by histones d) sometimes found in the form of plasmids

D

Inclusions found in bacteria generally would not include: a) granules b) volutin c) metachromatic granules d) ribosomes

D

Mycolic acid would be found primarily in the cell wall of: a) Gram positive bacteria b) Gram negative bacteria c) Gram variable bacteria d) acid-fast bacteria

D

Penicillin controls the growth of bacteria by _____. a) destroying cell membranes b) preventing protein synthesis c) removing cell walls d) preventing peptidoglycan synthesis

D

The periplasmic space is found _____. a) only in Gram positive organisms b) between the nuclear area and the cell membrane c) primarily in acid fast bacteria d) between the innercell membrane and outer cell wall membrane

D

When the fluid within a cell has a higher concentration of dissolved substances than the fluid surrounding the cell, we say the fluid surrounding the cell is _____. a) hypertonic b) isotonic c) superhypertonic d) hypotonic

D

Which of the following cellular structures can be found in both prokaryotic and eukaryotic cells? a) Golgi apparatus b) lysosomes c) peroxisomes d) ribosomes

D

Which of the following groups of organisms is not prokaryotic? a) Archaea b) Bacteria c) Eubacteria d) Eukarya

D

Which of the following is not found in bacterial cells? a) A cell membrane, usually surrounded by a cell wall b) An internal cytoplasm with ribosomes, a nuclear region and in some cases granules c) A variety of external structures, such as capsules, flagella and pili d) Respiratory enzymes contained in an internal structure surrounded by membranes

D

Which of the following is responsible for converting sunlight into chemical energy? a) Chromatophores b) Chloroplasts c) Endoplasmic reticulum d) Two of the above

D

Which of the following structures is not normally part of a bacterial flagellum? a) Hook b) Filament c) Basal body d) Anchor

D