Biology Review Book Flashcards
(104 cards)
1
Q
A child is diagnosed with an enzyme deficiency that prevents the production of hydrogen peroxide. What would likely be the outcome of such a deficiency?
A
peroxisomes are made of hydrogen peroxide and depend on it for function. The child will be unable to digest very long chain fatty acids… they would build up in the peroxisomes until displaced by other cell contents - ultimately result in cell death
2
Q
aerotolerant anaerobe (yes or no)
oxygen present: can survive? can carry out aerobic metabolism?
no oxygen: can survive? can carry out anaerobic metabolism?
A
yes no yes yes
3
Q
coronavirus is described as an enveloped, single-stranded positive-sense RNA virus. What does this indicate?
A
- the virus contains an outer layer of phospholipids with an inner capsid
- in the capsid there is a single stranded RNA that can be immediately translated to protein by the ribosomes of the host cell
4
Q
describe conjugation mechanism of bacterial genetic recombination
A
the transfer of genetic material from one bacterium to another across a conjugation 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
5
Q
Describe the pathway of retroviral nucleic acids from infection of host cell to release of viral progeny
A
- nucleic acid enters as single-stranded RNA
- RNA undergoes reverse transcription (using reverse transcriptase) to form a double-stranded DNA
- the DNA enters the host genome and replicates with the host cell
- the DNA is transcribed to mRNA which can be used to make structural proteins
- the mRNA doubles as the viral genome for new virions
- once new virions are assembled from the structural proteins and mRNA genome, they can be released to infect other cells
6
Q
describe transduction mechanism of bacterial genetic recombination
A
the transfer of genetic material from one bacterium to another by bacteriophage
7
Q
describe transformation mechanism of bacterial genetic recombination
A
the acquisition of exogenous genetic material that can be integrated into the bacterial genome
8
Q
difference between cytoskeletal structures of centrioles and flagella
A
centrioles consist of 9 triplets of microtubules around a hollow center
flagella consist of 9 doublets on the outside and 2 microtubules on the inside
9
Q
difference between lytic and lysogenic cycles?
A
lytic: bacteriophages replicate in the host cell in extremely high numbers until the host cell lyses and releases the virions
lysogenic: the bacteriophage genome enters the host genome and replicates with the host cell as a provirus; the provirus may leave the host genome and can be used to synthesize new virions
10
Q
epithelial or connective tissue cells? alpha cells which produce glucagon in the pancreas
A
epithelial cells
11
Q
epithelial or connective tissue cells? chondroblasts which produce cartilege
A
connective tissue cell
12
Q
epithelial or connective tissue cells? endothelial cells which line blood vessels
A
epithelial cells
13
Q
epithelial or connective tissue cells? fibroblasts which produce collagen in a number of organs
A
connective tissue cells
14
Q
epithelial or connective tissue cells? osteoblasts which produce osteoid, the material that hardens into bone
A
connective tissue cell
15
Q
facultative anaerobe (yes or no)
oxygen present: can survive? can carry out aerobic metabolism?
no oxygen: can survive? can carry out anaerobic metabolism?
A
yes yes yes yes
16
Q
Golgi apparatus
A
vesicle brings product to it… it then packages and modifies it before sending it off in another vesicle
17
Q
how do prions cause disease?
A
they trigger a change in the conformation of a protein from and alpha helix to a beta pleated sheet. this reduces the solubility of the protein and makes in highly resistant to degradation
18
Q
how do eukaryotic and prokaryotic flagella differ?
A
eukaryotic flagella contain microtubules composed of tubulin organized in 9+2 arrangement
bacterial flagella are made of flagellin and consist of filament, a basal body, and a hook
19
Q
in which ways are archaea similar to bacteria and eukaryotes
A
bacteria: single celled organism, no nucleus or membrane-bound organelles, have single circular chromosome, divide by binary fission or budding (prokaryotes)
eukaryotes: start translation with methionine, contain similar RNA polymerases, contain DNA associated with histones
20
Q
list all parts of cell theory
A
- all living things are composed of cells
- cells are the basic functional unit of all living things
- all cells come only from preexisting cells
- cells carry genetic information (DNA) and pass it down
21
Q
lysosome
A
break down cellular waste products and molecules ingested through endocytosis; can be involved in apoptosis
22
Q
mitochondrion
A
generate ATP (produce energy for the cell’s functions); apoptosis
23
Q
nucleus
A
stores genetic information; site of transcription
24
Q
obligate aerobe (yes or no)
oxygen present: can survive? can carry out aerobic metabolism?
no oxygen: can survive? can carry out anaerobic metabolism?
A
yes
yes
no
no
25
obligate anaerobe (yes or no)
oxygen present: can survive? can carry out aerobic metabolism?
no oxygen: can survive? can carry out anaerobic metabolism?
no no yes yes
26
peroxisomes
break down very long fatty acid chains, synthesize lipids, contribute to pentose phosphate pathway
27
Rough ER
synthesizes proteins destined for secretion
28
smooth ER
produces lipids; detoxification
29
what are the 3 common shapes of bacteria?
spherical (cocci)
spiral (spirilli)
rod (basilli)
30
what are the 4 phases of the bacterial growth curve.. list their features
1. lag phase - bacteria get used to environment; little growth
2. exponential phase - bacteria use available resources ot mltipy at an exponential rate
3. stationary phase - bacterial multiplication slows as resources are used up
4. death phase - bacteria die as resources become insufficient to support the colony
31
What are the predominant proteins in microfilaments and its function
solid polymerized rods of ACTIN which makes the cell resistant to compression and fracture
32
what difference between the envelopes of gram-positive and gram-negative bacteria make gram-positive bacteria more susceptible to antibiotics such as penicillin?
Penicillin targets the enzyme that catalyzes the cross-linking of peptidoglycan.
Gram-positive bacteria have a thick layer of peptidolycan and lipoteichoic acid and have NO outer memberane
Gram-negative bacteria only have a thin layer of peptidoglycan but also have an outer membrane containing lipopolysaccharides and phospholipids.
Penicillin and antibiotics with similar function can more easily reach and weaken the peptidoglycan layer of gram-positive bacteria
33
What is the predominant protein in microtubules and what is a microtubule
it is a cytoskeleton structure composed of protein tubulin. it provides primary pathways for motor proteins (kinesin and dynein) to carry vesicles
- cilia and flagella movement of materials
34
what is the protein in intermediate filaments and what is an intermediate filament
lots of proteins and depends on what filament you have (keratin, desmin, vimentin, lamin)
deals with cell to cell adhesion and the maintenance of the integrity of the cytoskeleton... withstands a lot of tension
35
Why are viruses considered obligate intracellular parasites?
viruses don't have ribosomes and organelles so in order for them to reproduce and synthesize proteins, they must infect cells and hijack their machinery
36
What are the 5 stages of the cell cycle? What happens in each stage?
```
G1 = cell grows and performs normal functions. DNA is examined and repaired
S = DNA is replicated
G2 = cell continues to grow and replicate organelles in preparation for mitosis; normal functions continue
M = mitosis (cell division)
G0 = the cell performs normal functions and is not preparing to divide
```
- G1/S checkpoint ensures DNA is in good condition
- G2/S checkpoint ensures organelles replicate and cell is appropriate size
p53 is the protein in control: when Tp53 gene is mutated the protein doesn't work, and therefore the DNA is not checked = cancer
37
What are the 4 phases of mitoses, and what happens in each phase?
```
prophase = chromosomes condense, nuclear membrane dissolves, nucleoli disappear, centrioles migrate to opposite poles of cell and begin forming spindle apparatus
metaphase = chromosomes gather along the metaphase plate in the middle of the cell under the guidance of the spindle apparatus
anaphase = sister chromatids separate and a copy of each chromosome migrates to opposite sides
telophase = chromosomes de-condense, nuclear membrane reforms, nucleoli reappear, spindle apparatus breaks down
cytokinesis = cell splits into two identical daughters
```
38
What is the number and ploidy of the daughter cells produced from meiosis I? meiosis II?
meiosis I = 2 haploid daughter cells
| meiosis II = up to 4 haploid daughter cells
39
What is the difference between homologous chromosomes and sister chromatids?
homologous chromosomes are related chromosomes of opposite parental origin (like having chromosome 15 from mom and chromosome 15 from dad).
sister chromatids are identical copies of the same DNA that are held together at the centromere.
After phase S, a cell contains 92 chromatids, 46 chromosomes, and 23 homologous pairs
40
For each phase of meiosis I what are the differences from the analogous phase of mitosis?
1. Prophase I = homologous chromosomes come together as tetrads during synapsis; crossing over
2. Metaphase I = homologous chromosomes line up on opposite sides of the metaphase plate, rather than individual chromosomes lining up on the metaphase plate
3. Anaphase I = homologous chromosomes separate from eachother (centromeres do not break)
4. telophase I = chromatin may or may not decondense; interkinesis occurs as the cell prepares for meiosis II
41
What are the 4 functions of the interstitial cells of Leydig and Sertoli cells?
interstitial cells of Leydig: secrete testosterone and other male sex hormones (androgens)
sertoli cells: nourish sperm during development
42
During which phase of meiosis is a primary oocyte arrested? During which phase of meiosis is a secondary oocyte arrested?
```
primary = prophase I
secondary = metaphase II
```
43
What is the acrosome? What organelle forms from the acrosome?
It contains enzymes that are capable of penetrating the corona radiata and zona pellucida of the ovum, permitting fertilization to occur. It is a modified Golgi apparatus.
44
Which hormones are key to sexual differentiation in a fetus with XY genotype? Describe the expected phenotype if receptors to these hormones are absent
Androgens (like testosterone) lead to male sexual difference. Without androgen receptors you could observe androgen insensitivity syndrome (XY genotype with phenotypically female characteristics)
45
What are the four stages of the female menstrual cycle? What are the features and relative hormone concentrations of each phase?
1. FOLLICULAR
- key features = egg develops, endometrial lining becomes vascularized and glandularized
- FSH increases
- LH remains the same
- Estrogen goes down then up
- Progesterone goes down
2. OVULATION
- key features = egg is released from follicle into peritoneal cavity
- FSH up
- LH up and up
- Estrogen up
- Progesterone down
3. LUTEAL
- key features = corpus luteum produces progesterone to maintain endometrium
- FSH down
- LH stays the same
- Estrogen up
- Progesterone up
4. MENSES
- key features = shedding of endometrium lining
- FSH down
- LH down
- Estrogen down
- Progesterone down
46
What is a blastula?
an embryo with a BLASTED out cavity. (from morula to blastula)
47
What is the difference between determinate and indeterminate cleavage?
```
determinate = cell division that results in cells having definitive lineages (at least one daughter cell is programmed to differentiate into a particular cell type)
indeterminate = cell division that results in cells that can differentiate into any cell type (or a whole organism)
```
48
From zygote to gastrula, what are the various stages of development?
zygote ---> 2,4,8, and 16 cell embryo ---> morula ---> blastula ---> gastrula
49
What causes spina bifida?
the neural tube fails to close
50
During which stage of development does implantation occur?
blastula (blastocyte) stage
51
What are the primary germ layers? and what organs are formed from each?
1. Ectoderm = epidermis, hair, nails, epithelia of the nose, mouth, and anal canal, lens of the eye, nervous system (including adrenal medulla), inner ear
2. Mesoderm = musculoskeletal system, circulatory system, excretory system, gonads, muscular and connective tissue layers of the digestive and respiratory systems, adrenal cortex
3. Endoderm = epithelial lining of digestive and respiratory tracts, and parts of liver, pancreas, thyroid, bladder, and distal urinary and reproductive tracts
52
What is induction and how does it influence development?
It is the process by which nearby cells influence the differentiation of adjacent cells. This ensures proper spatial location and orientation of cells that share a function or have complementary functions
53
What tissues do neural crests cells develop into?
peripheral nervous system (sensory ganglia, autonomic ganglia, adrenal medulla, Schwann cells) and specific cell types in other tissues (calcitonin-producing cells of the thyroid, melanocytes in the skin, and more)
54
What is the difference between determination and differentiation?
Determination is the commitment of a cell to a particular lineage (not reversible). Differentiation refers to the actual changes that occur in order for the cell to assume the structure and function of the determined cell type
55
What are the 3 types of potency? What lineages can a cell of each type differentiate into?
1. Totipotency = any cell type in the developing embryo (primary germ layers) or any extraembryonic tissues (amniotic, chorion, placenta)
2. Pluripotency = any cell time in the developing embryo (primary germ layers)
3. Multipotency = any cell type within a specific lineage (for example: hematopoietic stem cells)
56
What are the 4 types of cell-cell communication?
1. Autocrine = signal acts on the same cell that secreted it
2. Paracrine = the signal acts on local cells
3. Juxtacrine = a cell triggers adjacent cells through direct receptor stimulation
4. Endocrine = the signal travels via bloodstream to act on distant cells
57
What is the difference between apoptosis and necrosis?
```
apoptosis = programmed cell death which results in contained blebs of the dead cell that can be picked up and digested by other cells
necrosis = cell death due to injury that results in spilling of cytoplasmic contents
```
58
What is the oxygenation status of the blood in the umbilical arteries? In the umbilical vein?
umbilical arteries = carry deoxygenated blood away from fetus to placenta
umbilical veins = carry oxygenated blood to the fetus from the placenta
(oxygenation occurs at placenta - lungs do not function)
59
What are the 3 fetal shunts? What vessels or heart chambers do they connect? What organ does each shunt bypass?
1. foramen ovale; right atrium to left atrium; lungs
2. ductus arteriosis; pulmonary arteries to aorta; lungs
3. ductus venosus; umbilical vein to inferior vena cava; liver
60
List some key developmental features of each trimester.
```
1st = organogenesis occurs (development of heart, eyes, gonads, limbs, liver, brain)
2nd = tremendous growth; movement begins; the face becomes distinctly human; digits elongate
3rd = rapid growth and brain development; transfer of antibodies to the fetus
```
61
What occurs in each of the 3 phases of birth?
1. the cervix thins out and amniotic sac ruptures (water breaks)
2. uterine contractions, coordinated by prostaglandins and oxytocin, result in birth of the fetus
3. the placenta and umbilical cord are expelled
62
List 5 glial cells and brief function
1. astrocyte = nourish neurons and form blood-brain barrier
2. ependymal cells = line ventricles of brain and produce CSF
3. microglia = phagocytes that ingest and break down waste products and pathogens in central nervous system
4 + 5. oligodendrocytes (CNS) and Schwann cells (PNS) produce myelin around axons
63
axon
transmits electrical signal (the action potential) from the soma to the synaptic knob
64
axon hillock
integrates excitatory and inhibitory signals from the dendrites and fires an action potential if excitatory signals are strong enough to reach the threshold
65
dendrites
receive incoming signals and carry them to the soma
66
myelin sheath
acts as insulation around the axon and speed conduction
67
soma
cell body and contains the nucleus, endoplasmic reticulum, and ribosomes
68
synaptic bouton
lies at end of the axon and releases neurotransmitters
69
What is a collection of bodies called in the CNS? In the PNS?
```
CNS = nucleus
PNS = ganglion
```
70
Which of the 2 glial cells if NOT properly functioning will make an individual susceptible to a CNS infection?
Astrocytes (nourish neurons and form BBB) helps protect brain from foreign pathogens gaining entrance
Microglia ingest and break down waste products and pathogens
71
Guillain-Barre syndrome (GBS) is an autoimmune disease that causes demyelination of the PNS. What type of glial cell is being targeted in GBS?
oligodendrocytes
72
What neural structure initiates the action potential?
axon hillock
73
What entity maintains the resting membrane potential? What is the approximate voltage of resting membrane potential?
Na+/K+ ATPase at approximately - 70mV
74
What is the difference between temporal and spatial summation?
```
temporal = integration of multiple signals close to each other in time
spatial = integration of multiple signals close to each other in space
```
75
During the action potential which ion channel opens first? How is this ion channel regulated? What effect does the opening of this channel have on the polarization of the cell?
1. sodium channel opens first at threshold (around -50mV)
2. regulated by inactivation which occurs at around +35mV; inactivation can only be reversed by repolarizing the cell
3. depolarization
76
During the action potential which ion channel opens second? How is this ion channel regulated? What effect does the opening of this channel have on the polarization of the cell?
ion channel = potassium (-50mV)
regulated by closing at low potentials (slightly below -70mV)
causes repolarization and eventually hyperpolarization
77
What is the difference between absolute and relative refractory period?
```
absolute = cell unable to fire and action potential regardless of intensity of stimulus
relative = the cell can fire an action potential with a stronger than normal stimulus
```
78
What ion is primarily responsible for the fusion of neurotransmitter-containing vesicles with the nerve terminal membrane?
calcium
79
What are the 3 main methods by which a neurotransmitter's action can be stopped?
1. enzymatic degradation
2. reuptake
3. diffusion
80
What parts of the nervous system are in the CNS and PNS?
```
CNS = brain and spinal cord
PNS = cranial and spinal nerves and sensory nerves
```
81
What do afferent and efferent neurons do?
Afferent (sensory) neurons bring signals from the sensor to the central nervous system (AWAY from body to the head)
Efferent (motor) neurons bring signals from the CNS to an effector
82
What functions are accomplished by the somatic nervous system and autonomic nervous system?
```
Somatic = voluntary actions like moving muscles
Autonomic = involuntary processes like heart rate, bronchial dilation, dilation of pupils, exocrine gland function, peristalsis
```
83
Under the autonomic nervous system we have the parasympathetic and sympathetic divisions... explain them
parasympathetic = "rest and digest" with slowing heart rate and constricting bronchi, redistribution of blood to the gut, promoting exocrine secretions, constricting of pupils, promoting peristalsis and urinary functions
sympathetic = promotes "fight or flight" response with increased heart rate and bronchial dilation, redistribution of blood to locomotor muscles, dilation of the pupils, slowing of the digestive and urinary functions
84
What is the pathway of neural impulses in a monosynaptic reflex? In a polysynaptic reflex?
monosynaptic = a sensory (afferent, presynaptic) neuron fires directly onto a motor (efferent, postsynaptic) neuron
polysynaptic = a sensory neuron may fire directly onto a motor neuron, but interneurons are used as well
85
compare and contrast peptide and steroid hormones based on: chemical precursor, location of receptor, mechanism of action, method of travel in the bloodstream, speed of onset, duration of action
chemical precursor: peptide is amino acids (polypeptides) and steroid is cholesterol
location of receptor: peptide is extracellular (cell membrane) and steroid is intracellular or intranuclear
mechanism of action:
peptide = stimulates a receptor (usually a G protein - coupled receptor), affecting levels of second messengers (commonly cAMP). Initiates a signal cascade
method of travel in the bloodstream:
speed of onset:
duration of action:
86
compare and contrast peptide and steroid hormones based on: chemical precursor, location of receptor, mechanism of action, method of travel in the bloodstream, speed of onset, duration of action
chemical precursor: peptide is amino acids (polypeptides) and steroid is cholesterol
location of receptor: peptide is extracellular (cell membrane) and steroid is intracellular or intranuclear
mechanism of action:
peptide = stimulates a receptor (usually a G protein - coupled receptor), affecting levels of second messengers (commonly cAMP). Initiates a signal cascade
steroid = binds to a receptor, induces conformational change, and regulates transcription at the level of DNA
method of travel in the bloodstream: peptide is water-soluble so it flows through the bloodstream freely. steroids are not water-soluble so must use a carrier protein
speed of onset: peptides are fast and steroids are slow
duration of action: peptides are short-lived and steroids are long-lived
87
What is the difference between a direct and tropic hormone?
direct = secreted into bloodstream and travel to a target tissue where they have direct effects
tropic = cause secretion of another hormone that then travels to the target tissue to cause an effect
88
Products of the anterior pituitary? (mnemonic FLAT PEG)
```
F = follicle-stimulating hormone (FSH)
L = leutinizing hormone (LH)
A = adrenocorticotropic hormone (ACTH)
T = thyroid-stimulating hormone (TSH)
```
```
P = prolactin
E = endorphins
G = growth hormone (GH)
```
```
FLAT = tropic hormones
PEG = direct hormones
```
89
What are the functions of the corticosteroids? (mnemonic of the 3 S's)
```
Salt = mineralocorticoids
Sugar = glucocorticoids
Sex = cortical sex hormones
```
90
What is another word for red blood cells?
erythocytes
91
Pineal gland vs pituitary gland - how to remember location
pituitary gland is under the hypothalamus
| pinEAl gland is dEEp in the brain and deals with slEEp (melatonin)
92
For each of the hypothalamic releasing hormones listed, what hormones does each affect in the anterior pituitary? On which organ does each pituitary hormone act? What hormone(s) are released by the target organs?
1. Gonadotropin-releasing hormone (GnRH) = FSH and LH; Gonads (testes or ovaries); testosterone (testes) or estrogen and progesterone (ovaries)
2. Corticotropin-releasing factor (CRF) = adrenocorticotropic hormone (ACTH); adrenal cortex; glucocorticoids (cortisol and cortisone)
3. Thyroid-releasing hormone (TRH) = thyroid-stimulating hormone (TSH); thyroid; triiodothyronine (T3) and thyroxine (T4)
4. Dopamine = prolactin; breast tissue
5. Growth hormone-releasing hormone (GHRH) = growth hormone; bone and muscle
93
Which 2 hormones are primarily involved in calcium homeostasis? Where does each come from, and what effect does each have on blood calcium concentrations?
Calcitonin from the parafollicular (C-) cells of the thyroid decreases blood calcium concentration
Parathyroid hormone from the parathyroid glands increases blood calcium concentration
94
Which endocrine tissue synthesizes catecholamines? What are the 2 main catecholamines it produces?
Adrenal medulla - epinephrine and norepinephrine
95
Which 2 pancreatic hormones are the major drivers of glucose homeostasis? where does each come from and what effect does it have on blood glucose concentrations?
1. Glucagon - α cells of the pancreas and increases blood glucose levels
2. Insulin - β cells of pancreas and decreases blood glucose levels (diabetics have too much sugar in their blood bc insufficient insulin so we give them more to get rid of glucose)
96
Which 3 hormones are primarily involved in water homeostasis? Where does each come from, and what effect does each have on blood volume and osmolarity?
1. antidiuretic hormone (ADH or vasopressin) - from hypothalamus released by posterior pituitary; increases blood volume and decreases blood osmolarity
2. aldosterone - from adrenal cortex; increases blood volume with no effect on osmolarity
3. atrial natriuretic peptide (ANP) - from the heart; decreases blood volume with no effect on osmoraltiy
97
List the structures in the respiratory pathway from where air enters the nares to the alveoli.
nares to nasal cavity to pharynx to larynx to trachea to bronchi to bronchioles to alveoli
98
Which muscles are involved in inhalation and exhalation?
inhalation = diaphragm and external intercostal muscles; in labored breathing muscles of the neck and back may also be involved
passive exhalation uses the recoil of the muscles above
active exhalation uses internal intercostal muscles and abdominal muscles
99
What is the purpose of surfactant?
it reduces surface tension at the air-liquid interface in the alveoli. this prevents their collapse
100
What is the mathematical relationship between vital capacity (VC), inspiratory reserve volume (IRV), expiratory reserve volume (ERV), and tidal volume (TV)?
VC = IRV + ERV + TV
101
If blood levels of CO2 become too low, how does the brain later the respiratory rate to maintain homeostasis?
When CO2 levels become too low, the brain can decrease the respiratory rate in order to raise CO2 levels
102
What are some mechanisms used in the respiratory system to prevent infection?
vibrissae in the nares, lysozyme in the mucous membranes, the mucocilliary escalator, macrophages in the lungs, mucosal IgA antibodies, mast cells
103
What is the chemical equation for the bicarbonate buffer system?
CO2 (g) + H20 (l) -->< H2CO3 (aq) -->< H+ (aq) + HCO3- (aq)
104
Respiratory failure refers to inadequate ventilation to provide oxygen to the tissues. How would the pH change in respiratory failure?
Ventilation slows, less carbon dioxide is blown off .... as this happens, the buffer equation shifts to the right and more hydrogen ions are generated. This results in a lower pH of the blood
