Model Organisms (Lecture 3) Flashcards
What is a model organism?
Discoveries about biological structures and functions obtained with one organism are often applicable to others
What are the three useful feature of model organisms?
Small Easy feeding Non-dangerous Cheap Genome Sequence etc.
True or False: Bacteria are well-suited for studies on population dynamics, certain molecular mechanisms, cell growth, disease, antibiotic resistance, and evolutionary dynamics.
True
What is a unique characteristic of caulobacter crescentus?
Produces a stalk only at one end
What are the four most common bacteria used as model organisms?
E. coli, B. subtilis, Caulobacter crescentus, and Pseudomonas fluorescens
What are the 5 steps (key ideas when choosing a model organism)?
Focus of study (What organisms show the phenotype of the mechanism under study)
Techniques (Are particular lines need, knockout inbred etc.)
Data Collection (Which organism has the simplest genome)
Ethics (What organism will experience the least suffering)
Practical issues ( What organism will require the least time-consuming care, cheapest, shortest generation time etc.)
Why are yeasts a common model organism?
Combine many benefits of bacteria (small, short generation time, etc) in a eukaryotic cell
What is yeast used to investigate in model organisms?
Proteins in endoplasmic reticulum and Golgi complex
that promote protein secretion
Cell cycle regulators
Processes of DNA replication and transcription
Why is the haploid and diploid stage unique to yeast?
Benefits of yeast, can’t hide recessive traits if working with the haploid cell (only one copy of chromosome) whereas in diploid organisms, the recessive trait may not be expressed.
During vegetative growth of diploid cells, Saccharomyces cerevisiae reproduce by ______.
Budding
What causes diploid cells to form into haploid cells in saccharomyces cerevisiae?
Nutrient limitation, starvation
______ isolate and characterize mutants that lack the ability to do something that a normal organism can do.
Classical genetics
True or False: Mutations can occur randomly or be induced with a
chemical or physical mutagen.
True
What are temperature sensitive mutations?
Organism able to grow at the permissive temperature, but not at the nonpermissive temperature (usually higher)
Why do temperature sensitive mutations occur?
Rationale is an altered protein that functions at the
lower temperature, but unfolds and is nonfunctional at the higher temperature.
True or False: Biofilm is an example of true multicellularity life.
False, it is a form of simple
What are the four types of animal tissue?
Connective
Epithelial
Muscle
Nervous
What type of tissue is the site of physical work?
Muscle
What type of tissue is the protective layer?
Epitheal
What type of tissue is used for coordination action and voluntary movement?
Nervous
True or False: The dermal tissue in plants is similar to epithelial tissue in animal cells?
True
What tissue in the plant cell is known as delivery tissue?
Vascular tissue, xylem, phloem
What type of tissue in plant cells support structure and physical food storage?
Ground tissue
Plant cells keep interconnected by ______.
Plasmodesmata
Animal cells keep interconnected by ______ and ______.
Cell adhesion molecule (CAMs)
Collagen (polysaccharides and proteins)
Cells of the epithelium are ______ which means that the plasma membranes are organized into ‘top’ (apical) and ‘bottom’ (basal) regions
Polarized
______ connect between epidermal cells whereas ______ connect between epidermal cell and the basal lamina.
Desmosome, hemidesmosome
Layers of tissues ‘team up’ to form important body structures known as ______.
Organs
Why is blood vessels considered a organ>
Lined with endothelium to prevent blood cell leakage
Wrapped with smooth muscle to regulate blood flow (can contract or relax)
Outer layer of connective tissue to protect from stretching and rupture
True or False: 10% of human DNA play regulatory role whereas 90% of human DNA encodes proteins.
False, 90% regulatory role, 10% DNA encoded for proteins
What is the dauer stage in C. elegans life cycle?
pause phase
What is C. elegans a good model organism for?
Neurodegenerative diseases in humans
True or False: Humans and mice diverged about 75 Myr ago.
True
______ is occurrence of genes in the same order on a chromosome in two or more different species.
Synteny
______ would be a good model organism for stem cell research.
Planaria
Why do humans appear so different from other apes, when our genomes are so similar?
Genes are regulated during development of all metazoans from a single cell (fertilized egg)
Regulatory DNA sequences are bound by regulatory proteins that control a protein-coding gene may differ between organisms
______ have a mouth near blastopore & ventral nerve cord and ______ have a anus near blastopore & dorsal central nervous system.
Protostomes
Deuterostomes
Pax 6 and eyeless disease cause ______.
Aniridia
True or False: In genetic diseases, Many are caused by mutations in a single gene, encoding a single protein (monogenic).
True
DMD (Duchenne muscular dystrophy) have mutations in ______.
Dystrophin
What is dystrophin?
Encodes a very large protein that acts as part of an adaptor complex between actin filaments and the extracellular matrix protein, laminin
