BIOLOGY Flashcards
1
Q
connective tissues often form the support structure for epithelial cells, often known as the ________
A
stroma
2
Q
which kinds of nucleic acids could form the genome of a virus
A
all kinds - can be DNA or RNA, double or single stranded
3
Q
which of the following is surrounded by a single membrane : lysosomes, nuclei, mitochondria, ribosomes
A
lysosomes
- nuclei and mitochondria have a double membrane
- ribosomes don’t have a membrane
4
Q
prokaryotes have ribosomal subunits of _____ and ______ while eukaryotes have ribosomal subunits of ________ and ________
A
30S and 50S
40S and 60S
5
Q
______ is the primary protein in microtubules and _______ is the primary protein in microfilaments
A
tubulin ; actin
6
Q
what happens during the lytic cycle
A
the virus’s DNA takes control of the host cell’s genetic machinery and manufactures progeny
the host cell bursts (lyses) and releases virions capable of infecting other cells
- the outbreak stage
7
Q
what happens during the lysogenic cycle
A
viral DNA is added to the host cell’s genome where it can remain dormant for days or years
8
Q
what kinds of viruses have tail sheaths and tail fibers
A
bacteriophages - viruses that infect bacteria
9
Q
what three methods of bacterial recombination can account for genetic variability
A
transformation, conjugation and transduction
10
Q
what are F+ bacteria
A
F-positive bacteria that have a fertility factor in their plasmid
- allows it to form sex pilus for conjugation
11
Q
prokaryotic organisms are always ______ while eukaryotic organisms can be _______
A
single celled ; uni or multicellular
12
Q
describe the structure of the nucleus
A
surrounded by the nuclear membrane/envelope (a double membrane)
nuclear membrane has pores that allow for selective two-way exchange
13
Q
what are histones
A
organizing proteins around which linear DNA is wound
- further wound into linear strands known as chromosomes
14
Q
what is the function of the nucleolus
A
site of ribosomal RNA synthesis
15
Q
what is the function of the outer membrane of the mitochondria
A
serves as a barrier between the cytosol and inner environment of the mitochondrion
16
Q
what is the structure and function of the inner membrane of the mitochondria
A
- arranged in numerous infoldings called cristae in order to increase surface area
- contains molecules and enzymes necessary for the electron transport chain
17
Q
the space between the inner and outer membranes of the mitochondria is called the _______ and the space inside the inner membrane is called the ______
A
inter-membrane space
mitochondrial matrix
18
Q
what is cytoplasmic or extranuclear inheritance
A
the transmission of genetic material independent of the nucleus
- example: mitochondria can self-replicate
19
Q
which organelles can be responsible for cell apoptosis
A
mitochondria and lysosomes
20
Q
what is the function of lysosomes
A
membrane-bound structures containing hydrolytic enzymes that are capable of breaking down many different substrates
21
Q
what is autolysis
A
the destruction of cells and tissues by their own enzymes, specifically those released by lysosomes
22
Q
what is the function of endosomes
A
transport, package and sort cell material traveling to and from the membrane
23
Q
what is an example of a kind of cell that has no organelles at all?
A
red blood cell
24
Q
what is the function of the smooth endoplasmic reticulum
A
lipid synthesis, detoxification of drugs, transportation of proteins from rough endoplasmic reticulum to golgi
25
what is the function of the rough endoplasmic reticulum and how is it different from the smooth one
- different because it is studded with ribosomes which help its function
- mainly involved in protein synthesis as well as folding and sorting
26
materials from the endoplasmic reticulum are transported to the ______ in ______
golgi apparatus ; vesicles
27
what is the function of the golgi apparatus
modification and shipping of proteins/cellular products
28
what is the function of peroxisomes
contain hydrogen peroxide and break down long fatty acid chains via beta oxidation
- can also participate in the synthesis of phospholipids and contain some of the enzymes involved in the pentose phosphate pathway
29
what are the three components of the cytoskeleton
microtubules, microfilaments, and intermediate filaments
30
what are the functions of microfilaments
- provide protection for the cell because actin filament bundles are resistant to compression and fracture
- can also use ATP to generate force for movement by interacting with myosin (muscle contraction)
- play a role in cytokinesis (division of materials between daughter cells) by forming the cleavage furrow
31
what is the structure of microfilaments
made up of solid polymerized rods of actin
32
what is the structure of microtubules
hollow polymers of tubulin proteins
33
what protein are thick filaments composed of
myosin
34
what are the functions of microtubules
- provide the primary pathways along which motor proteins like kinesin and dynein carry vesicles
- can make up motile structures like cilia and flagella
35
how are cilia and flagella different
cilia are primarily involved in movement of materials along surface of the cell (cilia in respiratory tract move mucus) while flagella are involved in the movement of the cell itself
36
what is the structure of eukaryotic organelles of motility
9+2 structure - nine pairs of microtubules forming an outer ring with 2 microtubules in the center
37
where are centrioles found
region of the cell called the centrosome
38
how are centrioles involved in mitosis
migrate to opposite poles of the dividing cell and organize the mitotic spindle
the microtubules coming from the centrioles attach to the chromosomes via complexes called kinetochores and pull them apart
39
what are intermediate filaments
a diverse group of filamentous proteins including keratin, desmin, vimentin, and lamins
40
what are the functions of intermediate filaments
- involved in cell-cell adhesion
- maintenance of overall cytoskeleton integrity
- increase structural rigidity of cell because they can withstand large amounts of tension
- anchor other organelles
41
how are centrioles structured
as nine triplets of microtubules with a hollow center
42
what are the four types of tissues
epithelial, connective, muscle, and nervous
43
what are the functions of epithelial cells
- cover the body and line its cavities to protect against pathogen invasion and desiccation
- can be involved in absorption, secretion, and sensation
- different functions according to the organ in which they are found
44
what is the basement membrane
an underlying tissue of connective tissue that epithelial cells are tightly joined to in order to remain as one cohesive unit
45
parenchyma
functional parts of the organ
- mainly composed of epithelial cells
46
what does it mean that epithelial cells are polarized
one side faces a lumen and the other interacts with underlying blood vessels/structural cells
47
what are the three shapes of epithelial cells
cuboidal (cube-like), columnar (long and thin), and squamous (flat and scale-like)
48
simple epithelia vs stratified epithelia vs pseudostratified epithelia
simple - one layer of cells
stratified - multiple layers of cells
pseudostratified - appear to have multiple layers due to differences in cell height but actually just one
49
what are the functions of connective tissues
- support the body
- provide framework for epithelial cells to carry out their functions
- produce and secrete materials such as collegen and elastin to form the extracellular matrix
50
epithelial cells contribute to the _______ of an organ while connective tissues contribute to the ________
parenchyma (functional part) ; stroma (supportive part)
51
what are some bacterial targets of antibiotics
the flagellum and the ribosome
52
spherical bacteria are known as ______, rod-shaped bacteria are known as ______, and spiral-shaped bacteria are known as ______
cocci ; bacilli ; spirilli
53
obligate aerobes
bacteria that require oxygen for metabolism
54
obligate anaerobes
bacteria that cannot survive in the presence of oxygen
55
facultative anaerobes
can use oxygen if its present but it's not necessary
56
aerotolerant anaerobes
unable to use oxygen for metabolism but are not harmed by its presence
57
what is the envelope of prokaryotic cells
cell wall + inner cell membrane
58
what is the structure of gram-positive bacteria
cell walls consist of a thick layer of peptidoglycan
59
what is the structure of gram-negative bacteria
very thin cell walls that also contain peptidoglycan but a much smaller amount
- have outer membranes containing phospholipids and lipopolysaccharides
60
what aspects of gram-positive and negative bacteria cause an inflammatory response in humans
gram-positive - lipoteichoic acid
gram-negative - lipopolysaccharides
61
what does the antibiotic penicillin target
the enzyme (transpeptidase) that catalyzes the cross-linking of peptidoglycan
62
what is chemotaxis
ability of a cell to detect chemical stimuli and move toward or away from them
63
what are the three components of flagella
filament, basal body, hook
64
T or F: plasmids are considered part of the genome of bacteria
F
65
what are episomes
a subset of plasmids that are capable of integrating into the genome of the bacterium
66
what is binary fission
asexual reproduction in bacteria that produces clone daughters
67
what is transformation in bacteria
the integration of foreign genetic material into the host genome
68
explain bacterial conjugation
form of sexual reproduction that involves two cells forming a conjugation bridge that facilitates the transfer of genetic material
- unidirectional transfer from donor male (F+) to recipient female (F-)
- the F- female then becomes an F+ and can go on to donate to others
69
how is transduction different from other recombination processes
requires a vector - a virus that carries genetic material from one bacterium to another
70
what are transposons
genetic elements capable of inserting and removing themselves from the genome
71
what are the 4 phases of bacterial growth
lag (adapting to local conditions), exponential/log (rate of division increases after adaptation), stationary (reduction of resources slows reproduction), and death (depletion of environment, bacteria can no longer support themselves)
72
the protein coat of a virus is called a _______ and it may be surrounded by an _______
capsid ; envelope
73
T or F: enveloped viruses are easier to kill
T
74
what is the name for viral progeny
virions
75
what is the function of the tail sheath and fibers of bacteriophages
tail sheath acts as a syringe, injecting genetic material into the bacterium
tail fibers help the bacteriophage recognize and connect to the correct host cell
76
single-stranded RNA viruses may be _____ or ______ sense
positive ; negative
77
what are positive sense RNA viruses
single-stranded
- their genome can be directly translated to functional proteins by the ribosomes of the host cell
78
what are negative sense RNA viruses
single-stranded
- the strand acts as a template for synthesis of a complementary strand which can then be used for protein synthesis
- must carry an RNA replicase to ensure the complementary strand is made
79
what are retroviruses
enveloped, single-stranded RNA viruses where the virion contains two identical RNA molecules
- they carry an enzyme known as reverse transcriptase which synthesizes DNA from single-stranded RNA (allows it to integrate into the host cell genome which is why these are so difficult to treat)
80
what is an example of a retrovirus
HIV
81
what kind of viruses have to enter the nucleus in order to be transcribed
DNA viruses
82
T or F: viral genomes have to be returned to their original form before re-packaging
T
83
what are the three methods of progeny release for viruses
1. cell death - viruses spill out
2. lysis - cell bursts from being so full and viruses spill out (disadvantageous because viruses can't reuse this cell)
3. extrusion - leaves cell by fusing with plasma membrane
84
what does it mean for a virus to be in a productive cycle
virus that leaves cell using extrusion - keeps host cell alive so it can be continually used
85
viruses in the lytic phase are termed _______
virulent
86
viruses in the lysogenic phase are termed ______
prophages/proviruses
87
what are prions
infectious proteins that cause disease by triggering the misfolding of other proteins (usually the conversion of alpha helix to beta pleated sheet)
88
what are viroids
small pathogens consisting of a very short circular single-stranded RNA that infect plants
- cause disease by silencing genes
89
what is a viroid that affects humans
hepatitis D virus (harmless if not coinfected with hep B)
90
what is interphase
the collective of G1, S, and G2 phases
91
T or F: individual chromosomes are visible during interphase
F - they are in the less condensed form known as chromatin
92
what happens in the G1 stage of mitosis
this is the presynthetic gap and, here, cells create organelles for energy and protein production while also increasing in size
93
where are the restriction or check points in mitosis
between G1 and S and between G2 and M
94
what happens in the S stage of mitosis
the cell replicates its genetic material so that each daughter cell will have identical copies
95
what are sister chromatids
two identical chromatids bound together at the centromere (after synthesis stage)
96
what happens in the G2 stage of mitosis
this is the postsynthetic gap and, here, the cell goes through a quality control checkpoint
97
what is the G0 stage
an offshoot of G1 stage where the cell is simply carrying out its functions and not preparing for division
98
what is the main protein in control of regulating mitotic checkpoints
p53
99
what is the relationship between cyclins and cyclin-dependent kinases (CDKs)
-both responsible for the cell cycle
- CDKs require cyclins to be activated
- when CDK-cyclin complex is formed, this complex can then phosphorylate transcription factors
100
what is one of the most common mutations found in cancer
mutation of the gene that produces p53, called TP53
101
what happens in prophase
- condensation of chromatin into chromosomes
- nuclear membrane disappears
- centriole pairs separate and go to opposite pairs of the cell
- centrioles begin to form spindle fibers which attach to kinetochores of the chromosomes
102
what happens in metaphase
the kinetochore and spindle fibers interact to align the chromosomes at the metaphase/equatorial plate (middle of the cell)
103
what happens in anaphase
- centromeres split so each chromatid has its own centromere and separates from its sister
- sister chromatids pulled to opposite sides of the cell
104
what happens in telophase
- spindle apparatus disappears
- nuclear membrane reforms and chromosomes uncoil
- reverse of prophase
105
what happens in cytokinesis
separation of the cytoplasm and organelles; division into two daughter cells
106
which stage of mitosis has the lowest amount of DNA content and why
G1
- happens right after division and right before synthesis
107
meiosis results in how many cells
up to four nonidentical sex cells
108
Meiosis I results in _____________ being separated, generating _________ daughter cells; this is known as ____________
homologous chromosomes ; haploid ; reductional division
109
Meiosis II results in ____________ being separated, generating ________ daughter cells; this is known as ____________
sister chromatids ; haploid (no change in ploidy) ; equational division
110
explain the process of synapsis and when it occurs
happens during prophase 1 of meiosis and is when homologous chromosomes come together and intertwine
- each of these pairs is called a tetrad
- held together by a group of proteins called the synaptonemal complex
111
explain the process of crossing over and when it happens
- happens during prophase 1 of meiosis
- chromosomes in a tetrad may break at the point of contact (called the chiasma) and exchange equivalent pieces of DNA
- only occurs between homologous chromosomes and not sister chromatids
- a way of genetic recombination
112
where in the cell cycle can you see Mendel's second law (of independent assortment)
prophase 1 of meiosis - crossing over
113
where in the cell cycle can you see Mendel's first law (of segregation)
anaphase 1 of meiosis - disjunction (separation of homologous chromosomes)
114
what is disjunction
separation of homologous chromosomes in anaphase 1 of meiosis
115
what is interkinesis
short rest period between cell divisions where chromosomes partially uncoil
116
why are males called hemizygous
this is in respect to many of the genes on the X chromosome because they only have one copy
117
what is the SRY gene
sex-determining region Y
- codes for a transcription factor that initiates testis differentiation and the formation of male gonads
118
what are the two fundamental components of the testes
seminiferous tubules and interstitial cells of Leydig
119
sperm are produced in the ________ where they are nourished by _________
seminiferous tubules ; Sertoli cells
120
the cells of Leydig secrete ________
testosterone and other androgens
121
what is the ductus deferens and what does it do
layer of muscle around the vas deferens that can raise and lower the testis to maintain the proper temperature for sperm development
122
mnemonic for pathway of sperm through the male reproductive system
SEVEN UP
Seminiferous tubules
Epididymis
Vas deferens
Ejaculatory duct
Nothing
Urethra
Penis
123
what do the seminal vesicles contribute to the sperm
fructose for nourishment
124
what two things give sperm mildly alkaline properties
seminal vesicles and the prostate gland
125
in spermatogenesis, four haploid sperm are formed from a
spermatogonium
126
spermatogonium --> __________ (S stage) --> __________ (meiosis I) --> ____________ (meiosis II) --> __________ (maturation)
primary spermatocytes, secondary spermatocytes, spermatids, spermatozoa
127
where are sensory and mechanoreceptors located in the skin
epidermis and dermis
128
which processes regulate the body when temperature is above normal and how
vasodilation - widening of blood vessels ; relaxation of smooth muscle that surrounds the vessels
sweat - hypotonic solution secreted on the skin that causes cooling due to evaporation of water (endothermic process that absorbs heat from the body)
129
which processes regulate the body when temperature is below normal and how
vasoconstriction - narrowing of blood vessels ; contraction of smooth muscle
shivering - generates heat through contraction of skeletal muscle
130
what are the arrector pili muscles
muscles attached to hair follicles in the skin
- in cold environments, sympathetic signaling causes contraction of these muscles which causes piloerection (hair standing upright)
131
which layer of the skin controls thermal insulation/regulation of temperature
hypodermis (lowest layer/subcutaneous layer)
132
what are the 5 layers of the epidermis
stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, and stratum basale
133
what happens in the stratum basale
- deepest layer of the epidermis
- consists of a single row of stem cells that continually divide
- of the two daughter cells produced, one remains in the basal layer and the other differentiates into a mature keratinocyte
134
what does the stratum corneum consist of
- outermost layer of the epidermis
- 20-30 layers of dead keratin-filled cells
- functions as barrier protection (against pathogens, UV, water loss)
135
what are Langerhans cells
- dendritic immune cells found in the epidermis of the skin
- recognize and ingest antigens ; then show these antigens to T cells activating the adaptive immune response
136
what is thee difference between the adaptive vs innate immune response
the adaptive response is highly targeted to eliminate a specific pathogen whereas the innate response is generalized to attack any foreign substance
137
what is the flow of the excretory system
the functional unit of the kidney is the nephron ; each kidney has about 1 million nephrons ; the nephrons eventually empty into the renal pelvis which narrows to form the ureter ; urine travels through the ureter to the bladder ; urine goes from bladder to urethra to out of the body
138
what is a portal system
system consisting of two capillary beds in series through which blood must travel before returning to the heart
139
what are the three major portal systems in the body
1. kidney portal system : renal artery to loop of Henle
2. hypophyseal portal system : connects hypothalamus and anterior pituitary
3. hepatic portal system : connects gut tube and liver
140
what are the two layers of the kidney
cortex (outermost layer) and medulla (sits within the cortex)
141
explain the portal system of the kidney
- the renal artery branches out, passes through the medulla, and enters the cortex as afferent arterioles
- the capillary tufts from these afferent arterioles are glomeruli
- after blood passes through a glomerulus, the efferent arterioles then form a second capillary bed
- these capillaries surround the loop of Henle and are known as vasa recta
142
describe the structure of the nephron
- around the glomerulus is a cup-like structure known as Bowman's capsule
- Bowman's capsule leads to a long tubules with many distinct areas : the proximal convoluted tubule, the descending and ascending limbs of the loop of Henle, distal convoluted tubule, and collecting duct
143
the bladder has a muscular lining known as the _________
detrusor muscle
144
the internal urethral sphincter consists of ________ muscle and is under _______ control
smooth ; involuntary (parasympathetic)
145
the external urethral sphincter consists of _________ muscle and is under _______ control
skeletal ; voluntary
146
what is the micturition reflex
when the bladder is full, stretch receptors cause parasympathetic neurons to fire which contracts the detrusor muscle --> this causes the internal sphincter to relax ---> person then decides to relax external sphincter or not
147
explain the trends of hydrostatic and oncotic pressure in the nephrons
- hydrostatic pressure of glomerulus is much higher than that in Bowman's space which causes fluid to move into the nephron
- osmolarity of blood in glomerulus is higher than that of Bowman's space so oncotic pressure opposes movement of fluid into Bowman's space
- hydrostatic pressure is much larger than oncotic so overall net flow is still from blood into nephron
148
the movement of fluid into Bowman's space is governed by
Starling forces
149
filtration is movement of solutes from ________ to ________ at _________
secretion is movement of solutes from ________ to _________ at
reabsorption is the movement of solutes from _________ to _______
blood ; filtrate ; Bowman's capsule
blood ; filtrate ; anywhere besides Bowman's capsule
filtrate ; blood
150
what is the function of the proximal convoluted tubule
- site of bulk reabsorption of glucose, amino acids, soluble vitamins, salt, and water
- site of secretion for hydrogen ions, potassium ions, ammonia, and urea
151
what is the function of the descending limb of the loop of Henle
- it's permeable to water but not salt
- as filtrate moves, water is reabsorbed
- vasa recta and nephron flow in opposite directions which creates a countercurrent multiplier system that allows maximal reabsorption of water
152
what is the function of the ascending limb of the loop of Henle
- it's permeable to salt but not water
- passively and actively reabsorbs salt
- the diluting segment is in the outer medulla
153
what is the function of the distal convoluted tubule
- it's responsive to aldosterone and is a site of salt reabsorption and waste product excretion
- similar to proximal tubule
154
what is the function of the collecting duct
- it's responsive to both aldosterone and ADH and has variable permeability, which allows reabsorption of the right amount of water
155
what is aldosterone and how does it affect the kidney
- it's a steroid hormone regulated by the renin-angiotensin - aldosterone system
- increases sodium reabsorption in the distal convoluted tubule and collecting duct thereby increasing water reabsorption
- increases blood volume and pressure but no change in blood osmolarity
156
what is antidiuretic hormone (also known as vasopressin) and how does it affect the kidney
- peptide hormone synthesized by the hypothalamus an released by the posterior pituitary
- its release is stimulated by low blood volume and high blood osmolarity
- increases permeability of collecting duct to water, increasing water reabsorption
- results in increased blood volume and pressure and decreased blood osmolarity
157
what is the bicarbonate buffer equation
CO2 (g) + H2O (l) <-> H2CO3 (aq) <-> H+ (aq) + HCO3- (aq)
