Uses and Limitations of Model Organisms Flashcards
1
Q
Define Model Organism
A
Non-human species studied to understand biological phenomena, providing insights into other organisms.
2
Q
What is Developmental Biology?
A
Study of how organisms grow and develop from a single cell to a complex multicellular organism.
3
Q
What is a Nematode?
A
Roundworm; C. elegans is a model.
4
Q
Define Hermaphrodite
A
Organism with both male/female organs.
5
Q
What is Cryopreservation?
A
Preserving cells at low temps.
6
Q
Define RNA interference (RNAi)
A
RNA molecules inhibit gene expression.
7
Q
What is Toxicology?
A
Study of poisons and their effects.
8
Q
What is a Dauer?
A
Alternative C. elegans stage induced by harsh conditions.
9
Q
Define Metazoan
A
Multicellular animal.
10
Q
What isDrosophila melanogaster?
A
Fruit fly model organism.
11
Q
Define Life Cycle
A
Series of changes in an organism’s life.
12
Q
What is a Genome?
A
Complete set of genetic information.
13
Q
Define Chromosome
A
Structure carrying genetic information.
14
Q
What is an Autosome?
A
Non-sex chromosome.
15
Q
Define Polytene Chromosome
A
Giant chromosomes inDrosophilalarvae.
16
Q
What are Homologs?
A
Genes evolved from a common ancestor.
17
Q
What is Regenerative Biology?
A
Study of renewal and restoration of tissues.
18
Q
Define Dorsal Closure
A
Process inDrosophilaembryogenesis.
19
Q
What is Apoptosis?
A
Programmed cell death.
20
Q
Define High-Throughput Screening
A
Method for rapid scientific testing.
21
Q
What are Bioelectrosprays?
A
Technique for handling biological material.
22
Q
What isXenopus laevis?
A
African clawed frog model organism.
23
Q
Define External Development
A
Embryo develops outside the parent’s body.
24
Q
What is Microinjection?
A
Injecting a substance into a single cell.
25
Define Pseudotetraploid
Having four sets of chromosomes from genome duplication.
26
What isDanio rerio?
Zebrafish model organism.
27
Define Transparent Embryos
Embryos that allow visualization of internal structures.
28
What is Angiogenesis?
Formation of new blood vessels.
29
Define Regeneration
Renewal and restoration of tissues.
30
What does Ectothermic mean?
Relies on external heat.
31
What does Endothermic mean?
Generates internal heat.
32
What isArabidopsis thaliana?
Plant model organism.
33
Define Self-Fertilize (Selfing)
Fertilization by own gametes.
34
What does Autotrophic mean?
Produces own food.
35
What are Trichomes?
Hair-like plant structures.
36
Define Plastids
Plant cell organelles for photosynthesis.
37
What is Photorespiration?
Metabolic process in plants, consumes O2.
38
What are MADS-box Transcription Factors?
Factors in flower development.
39
What are MicroRNAs (miRNAs)?
Small RNAs regulating gene expression.
40
Define RNA-Induced Silencing Complex (RISC)
Complex that uses RNA to recognize mRNA.
41
What is Reverse Genetics?
Discovering gene function from DNA sequence.
42
Define Arbuscular Mycorrhizae
Symbiotic relationship between fungus and plant roots.
43
What is Strigolactone?
Plant hormones promoting mycorrhizal symbioses.
44
What is a key limitation of using model systems in biological research according to the text?
Bias in model selection.
45
What makes an organism a good model system? What are the criteria for a good model biological system?
Easy to maintain, convenient size, inexpensive, short life cycle, genetically manipulable, economically relevant.
46
What does the text suggest about the basic mechanisms of development across different animals?
Likely similar.
47
Who popularizedC. elegansas a genetic model? What is the scientific significance of Sydney Brenner in the context of model organisms?
Sydney Brenner.
48
What characteristic ofC. elegansmakes it easy to observe changes at the cellular level?
Transparency.
49
What makesC. eleganseasy to maintain in the lab?
Thrives in simple petri-dish culture, feeds on bacteria, and can be maintained at room temperature on agar plates.
50
How long does it take forC. elegansto proceed from a fertilized egg to a sexual adult?
3 days.
51
What was first discovered and applied inC. elegans? How didC. eleganscontribute to the field of genetics regarding gene function?
RNA interference (RNAi).
52
What poses a great difficulty in obtaining biochemical amounts ofC. elegansat later ages?
Small size (1mm in length).
53
How did Thomas Hunt Morgan contribute to genetics usingDrosophila?
Established the chromosomal basis of inheritance.
54
What is the completion time of the fruit fly life cycle at room temperature?
10-12 days.
55
Approximately what percentage of the human genome do humans and flies share as homologs?
0.6
56
Why isDrosophilaemerging as a valuable system for use in the clinical drug discovery process?
Model for wound healing.
57
What is an advantage of usingDrosophilaover vertebrate models in some studies?
Not subject to animal licensing laws.
58
What makes modeling immunological diseases like multiple sclerosis difficult inDrosophila melanogaster?
Vertebrate-specific factors.
59
Which frog species is a crucial model for understanding early vertebrate development?
Xenopus laevis.
60
How much bigger is theXenopus laevisegg compared to the mouse egg?
Approximately 2300 times.
61
Why areXenopusembryos amenable to manipulation?
Develop outside the body, allowing surgical or chemical treatments.
62
What is the approximate time it takes forXenopusto reach sexual maturity from fertilization?
1 year.
63
Why are mutagenesis screens less likely to be successful inXenopus? What is a significant limitation of using Xenopus for genetic studies due to its genome structure?
Pseudotetraploidy.
64
When did zebrafish first become prominent as a biological model?
1970s.
65
What percentage of genes do zebrafish share with humans? How is the genetic structure of zebrafish similar to that of humans, and why is this significant?
0.7
66
What unique ability do zebrafish have that is of interest to researchers?
Ability to repair heart muscle.
67
What is a limitation of using zebrafish in drug screening due to the chorion?
Possible interference with drug permeability.
68
How quickly canArabidopsisplants develop from seed to a plant bearing mature seeds?
6 weeks.
69
How doesArabidopsisobtain carbon and energy?
Capturing carbon dioxide and solar energy (autotrophy).
70
What model of floral development was discovered usingArabidopsis? What processes wasArabidopsisinstrumental in discovering?
ABCE model.
71
What are glucosinolates inArabidopsis, and what is their function?
Pungent compounds; deter herbivores.
72
What proportion of gene families present inArabidopsisare also present in other flowering plants?
About three out of four.
73
What is the primary method of propagation forC. elegans?
Self-fertilizing hermaphrodite.
74
What is a major drawback of usingC. elegansfor studying certain aspects of aging?
Lack of important physiological systems, especially the immune system.
75
How does the size of the fruit fly genome compare to the human genome?
Approximately 5% of the size.
76
Besides regenerative biology, what other areas have recent studies usedDrosophilaas a model for?
Clinical drug discovery process, studying the biological safety of bioengineering technologies.
77
What is a unique advantage of using zebrafish embryos as a model in research?
Transparent, allowing easy examination of internal structures during development.
78
What percentage of genes known to be associated with human disease have a zebrafish counterpart?
0.84
79
How does the zebrafish being ectothermic affect its suitability as a human model?
Physiological differences compared to humans.
80
How long does it typically take forArabidopsisplants to germinate and grow hundreds on a single Petri dish?
Small seeds and seedlings can germinate by the hundreds on a single Petri dish.
81
What is a major application ofArabidopsisresearch due to its chemical diversity and autotrophic nature?
Study of tremendous chemical and enzymatic diversity.
82
In what areas isC. elegansused as an animal model?
Neurobiology, developmental biology, genetics, toxicology, aging research.
83
Why isDrosophilaindispensable for basic research, according to the text?
Low cost, rapid generation time, and excellent genetic tools.
84
What applications have recent studies explored usingDrosophilaas a model?
Wound healing, clinical drug discovery, and assessing the biological safety of bioengineering technologies.
85
What characteristics ofXenopusmake it suitable for spinal cord studies?
Transparent eggshell and simpler spinal cord organization.
86
What are Xenopusoocytes widely used for?
Premierin vitrosystem for studies of fundamental aspects of cell and molecular biology; environmental toxicology assays.
87
What are some of the anatomical differences between zebrafish and humans that limit their use as a model?
Lack of heart septation, synovial joints, cancellous bone, limbs, lungs, etc.
88
What are the main advantages of usingArabidopsis thalianaas a model organism?
Fast, cheap, convenient research; small genome size; high homozygosity; self-fertility; autotrophy; chemical diversity; multicellularity; typical plant features; conserved gene families.
89
How doesArabidopsiscontribute to studying chemical and enzymatic diversity?
Through its autotrophic nature and chemical defenses like glucosinolates.
90
According to the text, what undermines the fundamental assumptions of using model systems?
The way we select our models.
91
What makes Xenopusan invaluable tool in biological research?
Tool to study vertebrate embryology, development, basic cell and molecular biology, genomics, neurobiology and toxicology, and to model human diseases.
