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Biology: explore STEM content (page 30 of 50) · openstem
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Biology
Cells, genetics, ecology and physiology on openstem — flashcards, notes, quizzes, sketches and flowcharts shared by the community. Study free, or clone anything into your library.
A joint is the point where two or more bones meet. Joints are classified both by the type of tissue connecting the bones and by how much movement they allow.
When Immunity Misfires The immune system is normally very good at telling harmless things apart from real threats, and at telling the body's own cells apart from foreign invaders. Sometimes, though, this system gets it wrong. Two important
Biology
Biology · L3 · Allergies and Autoimmune Disease: When Immunity Misfires
How Scientists Name a New Species Even today, scientists find plants and animals nobody has ever described before — deep in rainforests, on the ocean floor, or even hiding in plain sight. Turning that discovery into an official new species
AA pigment made by skin cells that gives skin, hair, and eyes their colorBA vitamin the skin absorbs from sunlightCA layer of dead skin cells on the surface of the bodyDA type of muscle found in the dermis
Define a network motif in a gene regulatory network and describe the feed-forward loop (FFL) as a canonical example.1 / 9
A network motif is a small subgraph pattern (a specific arrangement of a few nodes and edges) that recurs in a regulatory network far more often than expected in a randomized network with the same degree distribution, implying it has been selected for a specific dynamical function.
Biology
Biology · L5 · Systems Biology and Network Modeling
From sunlight to sugar Glucose is the central energy currency of life — a six-carbon ring built from carbon, hydrogen, and oxygen: Photosynthesis is how plants build glucose from carbon dioxide and water using light. The equation is balance
Biology
Biology · L3 · Molecules of Life: Glucose and Photosynthesis
Born Alive or Hatched From an Egg? Every animal starts life in one of two ways. Some babies grow inside their mother and are born alive. Other babies grow inside an egg outside their mother's body, and then hatch out. Born Alive When an ani
Before an antibiotic is ever used against a bacterial population, is there already variation among the bacteria?1 / 10
Yes. Random mutations happen constantly as bacteria reproduce, so even before any drug is introduced, a large population almost always contains a few cells that happen to carry traits — including ones that make them harder for a particular antibiotic to kill.
Biology
Biology · L3 · Natural Selection and Antibiotic Resistance
In X-ray crystallography, what is the 'phase problem', and why does it arise specifically at the detection step of the experiment?
ADetectors cannot resolve reflections at high scattering angles, so high-resolution phases are unmeasurable.BA detector records diffraction intensity (amplitude squared) but not the phase of each scattered wave, so phases must be recovered by an independent method before Fourier synthesis of electron density.CProtein crystals diffract too weakly at all resolutions to give any usable intensities.DX-ray sources are not sufficiently monochromatic to define a single phase per reflection.
Biology
Biology · L5 · Structural Biology and Protein Chaperones
Why do plants need defenses at all, since they cannot run away from a hungry animal?1 / 10
Because a plant is rooted in place, it cannot flee a herbivore the way an animal can run from a predator. Instead, plants rely on structural and chemical defenses built into their tissues, along with occasional help from animal partners, to discourage or survive being eaten.
Biology
Biology · L3 · Physical and Chemical Plant Defenses
Microbial Genetics and Pathogenesis Bacteria evolve fast, and not only through mutation. A single bacterial cell can acquire a fully functional gene — for antibiotic resistance, for a toxin, for a new metabolic pathway — from another cell o
Biology
Biology · L4 · Microbial Genetics and Pathogenesis
Distinguish in situ from ex situ conservation, and give an example of each.1 / 10
In situ conservation protects species within their natural habitat, such as establishing a national park or marine protected area, preserving not just the target species but the full ecological community and evolutionary processes it participates in. Ex situ conservation protects species outside their natural habitat, such as captive breeding programs, zoos, seed banks, or cryopreserved genetic material, providing insurance against extinction in the wild and a source for reintroduction, but generally cannot replicate natural selection pressures or the full ecological interactions of the wild habitat, and can risk domestication-like selection or loss of natural behaviors over generations in captivity.
Biology
Biology · L4 · Conservation Strategies and Ecosystem Management
The Engineering Paradigm in Biology Classical genetic engineering typically produces bespoke, one-off constructs: a gene is cloned into a plasmid to answer a specific experimental question, with little expectation that the resulting DNA is
Biology
Biology · L5 · Synthetic Biology Engineering: Design Principles to Deployed Systems