Biology Chapter 1: The Cell (4 Stars)

Question 1

 The cell theory has 4 basic tenets:

Answer 1

All living things = cells.
cell = functional unit of life.
Cells arise only from preexisting cells.
Cells carry genetic information in the form of DNA. This genetic material is passed on from parent to daughter cell.

Question 2

Viruses are not considered living things because they are acellular, _______ without the assistance of a host cell, and may contain RNA as their genetic material.

Answer 2

cannot reproduce

Question 3

Eukaryotes have _______ organelles, a nucleus, and may form multicellular organisms.

Answer 3

membrane-bound

Question 4

The cell membrane and membranes of organelles contain ________, which organize to form hydrophilic interior and exterior surfaces with a hydrophobic core.

Answer 4

phospholipids

Question 5

The _______ suspends the organelles and allows diffusion of molecules throughout the cell.

Answer 5

cytosol

Question 6

The ______ contains DNA organized into chromosomes. It is surrounded by the nuclear membrane or envelope, a double membrane that contains nuclear pores for two-way exchange of materials between the ______ and cytosol. DNA is organized into coding regions called genes.

Answer 6

nucleus

Question 7

The ______ is a subsection of the nucleus in which ribosomal RNA (rRNA) is synthesized.

Answer 7

nucleolus

Question 8

Mitochondria contain an outer and inner membrane. The _____membrane forms a barrier with the cytosol; the ______ membrane is folded into cristae and contains enzymes for the electron transport chain. Between the membranes is the intermembrane space; inside the inner mitochondrial membrane is the __________.

Answer 8

inner membrane.
outer membrane
mitochondrial matrix.

Question 9

_______ contain hydrolytic enzymes that can break down substances ingested by endocytosis and cellular waste products. When these enzymes are released, autolysis of the cell can occur.

Answer 9

Lysosomes

Question 10

The endoplasmic reticulum (ER) is a series of interconnected membranes and is continuous with the _________. The rough ER (RER) is studded with ribosomes, which permit ________ of proteins destined for secretion. The smooth ER (SER) is used for lipid synthesis and detoxification.

Answer 10

nuclear envelope.
translation

Question 11

The Golgi apparatus consists of stacked membrane-bound sacs in which cellular products can be _______, packaged, and directed to specific cellular locations.

Answer 11

modified

Question 12

________ contain hydrogen peroxide and can break down very long chain fatty acids via β-oxidation. They also participate in phospholipid synthesis and the pentose phosphate pathway.

Answer 12

Peroxisomes

Question 13

The _______ provides stability and rigidity to the overall structure of the cell, while also providing transport pathways for molecules within the cell.

Answer 13

cytoskeleton

Question 14

________ are composed of actin. They provide structural protection for the cell and can cause muscle contraction through interactions with myosin. They also help form the cleavage furrow during cytokinesis in mitosis.

Answer 14

Microfilaments

Question 15

Microtubules are composed of tubulin. They create pathways for motor proteins like _____ and ______ to carry vesicles.

Answer 15

kinesin and dynein

Question 16

________ filaments are involved in cell–cell adhesion or maintenance of the integrity of the cytoskeleton; they help anchor organelles. Common examples include _______ and ______.

Answer 16

Intermediate

keratin and desmin.

Question 17

________ tissues cover the body and line its cavities, protecting against pathogen invasion and desiccation. Some epithelial cells absorb or secrete substances, or participate in sensation.

Answer 17

Epithelial

Question 18

In most organs, epithelial cells form the _______, or the functional parts of the organ.

Answer 18

parenchyma

Question 19

Epithelial cells may be _______, with one side facing a lumen or the outside world, and the other side facing blood vessels and structural cells.

Answer 19

polarized

Question 20

Epithelia can be classified by the number of layers they contain: _______ epithelia have one layer, stratified epithelia have many layers, and _________ epithelia appear to have multiple layers because of differences in cell heights, but actually have only one layer.

Answer 20

simple epithelia

pseudostratified epithelia

Question 21

Epithelia can be classified by the shapes of the cells they contain: cuboidal cells are cube-shaped, columnar cells are long and _______, and squamous cells are ____ and scalelike.

Answer 21

columnar cells are narrow

squamous cells are flat

Question 22

Connective tissues support the body and provide a framework for ______ cells.

Answer 22

epithelial cells.

Question 23

In most organs, connective tissues form the stroma or support structure by secreting materials to form an ________ matrix.

Answer 23

extracellular matrix.

Question 24

Bone, cartilage, tendons, ligaments, adipose tissue, and _____ are all connective tissues.

Answer 24

blood

Question 25

Prokaryotes do not contain membrane-bound organelles; they organize their genetic material in a single _______ molecule of DNA concentrated in the nucleoid region.

Answer 25

circular

Question 26

\_\_\_\_\_ are often extremophiles, living in harsh environments (high temperature, high salinity, no light) and often using alternative sources of energy, like chemosynthesis. They have similarities to both eukaryotes (start translation with methionine, similar RNA polymerases, histones) and bacteria (single circular chromosome, divide by binary fission or budding).

Answer 26

Archaea

Question 27

\_\_\_\_\_\_ is the only non-prokaryotic domain.

Answer 27

Eukarya

Question 28

Spherical bacteria are called \_\_\_\_\_\_

Answer 28

cocci.

Question 29

Rod-shaped bacteria are called \_\_\_\_\_\_\_

Answer 29

bacilli.

Question 30

Spiral-shaped bacteria are called \_\_\_\_\_

Answer 30

spirilli.

Question 31

\_\_\_\_\_\_ aerobes require oxygen for metabolism.

Answer 31

Obligate

Question 32

Obligate ________ cannot survive in oxygen-containing environments and can only carry out anaerobic metabolism.

Answer 32

anaerobes

Question 33

\_\_\_\_\_\_\_\_\_ can survive in environments with or without oxygen and will toggle metabolic processes based on the environment.

Answer 33

Facultative anaerobes

Question 34

\_\_\_\_\_\_\_\_\_ cannot use oxygen for metabolism, but can survive in an oxygen-containing environment.

Answer 34

Aerotolerant anaerobes

Question 35

The cell wall and cell membrane of bacteria form the \_\_\_\_\_\_\_. Together, they control the movement of solutes into and out of the cell.

Answer 35

envelope

Question 36

Bacteria can be classified by the color their cell walls turn during Gram staining with a crystal violet stain, followed by a counterstain with safranin. Gram-positive bacteria turn \_\_\_\_\_\_\_\_,

Answer 36

purple

Question 37

Gram-\_\_\_\_\_\_\_ bacteria have a thick cell wall composed of peptidoglycan and lipoteichoic acid.

Answer 37

positive (purple)

Question 38

Gram-negative bacteria have a _____ cell wall composed of peptidoglycan and an outer membrane containing phospholipids and lipopolysaccharides.

Answer 38

thin (pink)

Question 39

Bacteria may have one, two, or many flagella that generate propulsion to move the bacterium toward food or away from immune cells. Moving in response to chemical stimuli is called\_\_\_\_\_\_\_\_. Bacterial flagella contain a filament composed of flagellin, a basal body that anchors and rotates the flagellum, and a ______ that connects the two.

Answer 39

chemotaxis. hook

Question 40

Prokaryotes carry out the electron transport chain using the ____ membrane.

Answer 40

cell

Question 41

Prokaryotic ribosomes are _______ than eukaryotic ribosomes

Answer 41

smaller (30S and 50S, rather than 40S and 60S).

Question 42

Prokaryotes multiply through \_\_\_\_\_\_\_, in which the chromosome replicates while the cell grows in size, until the cell wall begins to grow inward along the midline of the cell and divides it into two identical daughter cells.

Answer 42

binary fission

Question 43

In addition to the single circular chromosome in prokaryotes, extrachromosomal material can be carried in \_\_\_\_\_\_\_.

Answer 43

plasmids. Plasmids may contain antibiotic resistance genes or virulence factors.

Question 44

\_\_\_\_\_\_\_\_ is the acquisition of genetic material from the environment, which can be integrated into the bacterial genome.

Answer 44

Transformation

Question 45

\_\_\_\_\_\_\_\_\_ is the transfer of genetic material from one bacterium to another across a ______ bridge; a plasmid can be transferred from F+ cells to F– cells, or a portion of the genome can be transferred from an Hfr cell to a recipient.

Answer 45

Conjugation

Question 46

\_\_\_\_\_\_\_\_ is the transfer of genetic material from one bacterium to another using a bacteriophage as a vector.

Answer 46

Transduction

Question 47

\_\_\_\_\_\_\_\_\_ are genetic elements that can insert into or remove themselves from the genome.

Answer 47

Transposons

Question 48

The bacteria adapt to new local conditions during the ______ phase.

Answer 48

lag

Question 49

Growth then increases exponentially during the _______ phase.

Answer 49

exponential (log) phase.

Question 50

As resources are reduced, growth levels off during the ______ phase.

Answer 50

stationary phase.

Question 51

As resources become insufficient, bacteria undergo a ______ phase.

Answer 51

death

Question 52

Viruses contain genetic material, a \_\_\_\_\_\_\_\_, and sometimes a lipid-containing envelope.

Answer 52

a protein coat (capsid)

Question 53

Viruses are ______ intracellular parasites, meaning that they cannot survive and replicate outside of a host cell. Individual virus particles are called virions.

Answer 53

obligate

Question 54

Bacteriophages are viruses that target \_\_\_\_\_\_\_. In addition to the other structures, they contain a tail sheath, which injects the genetic material into a bacterium, and \_\_\_\_\_\_\_, which allow the bacteriophage to attach to the host cell.

Answer 54

bacteria. tail fibers

Question 55

\_\_\_\_\_\_\_ may be composed of DNA or RNA and may be single- or doublestranded.

Answer 55

Viruses

Question 56

Single-stranded RNA viruses may be __________ (can be translated by the host cell) or _________ (a complementary strand must be synthesized using RNA replicase, which can then be translated).

Answer 56

positive sense negative sense

Question 57

Retroviruses contain a single-stranded _____ genome, to which a complementary DNA strand is made using reverse transcriptase.

Answer 57

RNA DNA strand can then be integrated into the genome.

Question 58

Viruses infect cells by attaching to specific receptors, and then either fusing with the plasma membrane, being brought in by \_\_\_\_\_\_\_, or injecting their genome into the cell.

Answer 58

endocytosis

Question 59

The virus reproduces by replicating and translating genetic material using the host cell’s ribosomes, \_\_\_\_\_, amino acids, and enzymes.

Answer 59

tRNA,

Question 60

Viral _______ are released through cell death, lysis, or extrusion.

Answer 60

progeny

Question 61

In the lytic cycle, the bacteriophage produces massive numbers of new _____ until the cell lyses.

Answer 61

virions

Question 62

In the \_\_\_\_\_\_\_, the virus integrates into the host genome as a provirus or prophage, which can then reproduce along with the cell.

Answer 62

lysogenic cycle, The provirus then leaves the genome in response to a stimulus at some later time and enters the lytic cycle.

Question 63

\_\_\_\_\_ are infectious proteins that trigger misfolding of other proteins, usually converting an α-helical structure to a β-pleated sheet. This decreases the solubility and degradability of the misfolded protein.

Answer 63

Prions

Question 64

\_\_\_\_\_ are plant pathogens that are small circles of complementary RNA that can turn off genes, resulting in metabolic and structural derangements of the cell and—potentially—cell death

Answer 64

Viroids

Question 65

DNA is organized into coding regions called \_\_\_\_\_.

Answer 65

DNA is organized into coding regions called genes.

Question 66

Mitochondria can divide independently of the nucleus via \_\_\_\_\_\_\_\_; they can trigger apoptosis by releasing mitochondrial enzymes into the cytoplasm.

Answer 66

binary fission

Question 67

Microtubules contribute to the structure of cilia and flagella, where they are organized into # ____ pairs of microtubules in a ring with two microtubules at the center. Centrioles are found in centrosomes and are involved in microtubule organization in the mitotic spindle.

Answer 67

nine pairs (9 + 2 structure)

Question 68

\_\_\_\_\_\_\_\_\_ are found in centrosomes and are involved in microtubule organization in the mitotic spindle.

Answer 68

Centrioles

Question 69

gram-negative bacteria turn \_\_\_\_\_\_\_\_.

Answer 69

pink

Question 70

Plasmids that can integrate into the genome are called \_\_\_\_\_\_\_

Answer 70

episomes.

Question 71

Individual virus particles are called \_\_\_\_\_\_\_

Answer 71

virions.

Question 72

Bacteria in the _____ phase are termed virulent.

Answer 72

lytic

Question 73

Mitochondria is also know as ______ of the cell

Answer 73

Powerhouse

Question 74

Identify the bacteria present in the testtube. Facultative Aerobes Obligate Anaerobes Acrotocrant anaerobes Obligate Aerobes Microacrophilcs

Answer 74

Oxygen would be expected to be present at the top of the tube and absent at the bottom. Therefore, obligate aerobes (#1 in Figure 15) would only be found at the top, and obligate anaerobes (#2) only at the bottom. Facultative aerobes (#3) would be found throughout the tube, but with a greater distribution at the top due to the increased efficiency of aerobic metabolism. So-called microacrophilcs (#4) arc a group of microorganisms that require oxygen for metabolism but arc poisoned by high concentrations. Acrotolcrant anaerobes (#5) would be spread evenly throughout the tube.

Question 75

Idenitify the missing cell components

Answer 75