Cycle 1 Flashcards
Q: What is Chlamydomonas reinhardtii?
A: It is a eukaryotic green algae with flagella (2), a cell wall with a plasma membrane, and an eyespot (red dot).
Q: Why are haploid Chlamydomonas cells grown in the lab?
A: Haploid cells allow mutant phenotypes to be expressed without being masked by wild-type genes.
Q: How does the size of bacteria compare to a eukaryotic cell?
A: Bacteria (1 µm) are much smaller than a eukaryotic cell (10-100 µm).
Q: What are the key features of eukaryotic cells?
A: Complex cells with a membrane-bound nucleus, linear DNA associated with histones, membrane-bound organelles, larger ribosomes, and division by mitosis and meiosis.
Q: What are the key features of prokaryotic cells?
A: Simple, single-celled organisms without a true nucleus, circular DNA, no membrane-bound organelles, smaller ribosomes, and they divide by binary fission.
Q: What are the phases of Chlamydomonas growth?
A: Lag phase (adjustment), exponential phase (fastest growth, ~10 hours), and stationary phase (growth stops).
Q: Why is copper important for Chlamydomonas?
A: Copper activates enzymes, aids in iron metabolism, and supports the immune system.
Q: Why is sulfur important for Chlamydomonas?
A: Sulfur is essential for protein synthesis, vitamin formation, and detoxification.
Q: How does Chlamydomonas grow?
A: Through binary fission, dividing approximately every 10 hours.
Q: How are Chlamydomonas and plants related?
A: They share a common ancestor from 1 billion years ago, but plants lost their flagella through evolution.
Q: What conditions are needed to grow Chlamydomonas?
A: Moderate light, 24-28°C temperature, and a TAP growth medium with macronutrients and micronutrients.
Q: Why are Chlamydomonas flagella homologous to animal flagella?
A: They are structurally and functionally similar, indicating shared ancestry.
Q: What protein polymer forms the structure of cilia/flagella?
A: Microtubules, made from alpha-beta tubulin subunits.
Q: What motor protein causes the bending action in cilia/flagella?
Dynein
Q: What are ciliopathies?
A: Diseases caused by defective cilia, which may result in infertility, respiratory problems, or sensory issues in eyes, nose, and ears.
Q: How many Chlamydomonas proteins are shared with Arabidopsis and humans?
A: 33% of its proteins are shared with both.
Q: Are prokaryotic and eukaryotic flagella homologous?
A: No, they are analogous, having evolved independently through convergent evolution.
Q: What is the role of non-motile (sensory) cilia?
A: They house sensory proteins crucial for vision, hearing, and smell.
Q: What percentage of Chlamydomonas proteins are perfect homologs with humans?
A: 10%.
Q: What percentage of Chlamydomonas proteins are shared with Arabidopsis?
A: 26%.
Q: What are the two different uses of light in Chlamydomonas?
Light is used for energy (via chloroplasts)
Light provides information (via the eyespot)
Q: What technique is used to study proteins in Chlamydomonas?
A: SDS-PAGE, which separates proteins based on size.
What is an organelle and how does the new definition specify it?
A:
An organelle is a specialized structure within eukaryotic cells that is surrounded by a membrane. It must be membrane-bound.
Q: Why do Chlamydomonas cells move away from light?
A: They move away from light to prevent damage to the chloroplast and other components.
