Biology

Evolution, biochemistry, physiology and ecology, answered with evidence.

• How Does Artificial Selection Work?
  Artificial selection changes populations when humans repeatedly breed organisms with desired heritable traits, as seen in crops, livestock, and dogs.
• If a Tortoise Lost Its Shell, Would It Be Naked or Homeless?
  A tortoise would be neither naked nor homeless: its shell is part of its skeleton, and losing it would be a catastrophic injury.
• Enzyme Specificity vs. Selectivity: What Is the Difference?
  Enzyme specificity describes what an enzyme can act on; selectivity describes its preference among alternatives, though usage varies by context.
• Do Snakes Get Dizzy?
  Snakes have inner-ear balance organs, so movement can disorient them; whether they feel dizziness like humans do cannot be known directly.
• Can Paternal Meiosis II Nondisjunction Cause an XXY Male?
  Paternal meiosis II nondisjunction ordinarily makes XX or YY sperm, not XY sperm; see which chromosome errors can produce an XXY male.
• Can You Identify This Tiny Insect Larva?
  A tiny larva cannot be identified reliably from a description alone. Learn which photos, measurements, and habitat details help narrow it down.
• Can Acidic Drinks Kill Bacteria in the Stomach?
  Acidic drinks do not reliably kill stomach bacteria: stomach acid is stronger, and infections such as H. pylori need evidence-based treatment.
• Calcium: Supplements or Fortified Foods?
  Calcium from fortified foods is generally a practical alternative to supplements; compare labels, estimate your dietary intake, and supplement only a shortfall.
• Which Animals Can Walk Backward?
  Many animals can move backward, but the ability depends on their limbs and gait. Learn which animals can back up and why it is often awkward.
• Are Humans the Only Species That Drink Milk as Adults?
  Humans are not the only animals that can drink milk, but regularly harvesting and consuming milk after weaning is a distinctive human practice.
• Are the Eight Sugars in Glycoproteins Essential Nutrients?
  The eight sugars often listed as glycoprotein building blocks are not established dietary essentials; human cells can synthesize their sugar units.
• How Do Basic Programming Skills Help in Bioinformatics?
  Basic programming helps you organize, analyze, and repeat biological data tasks. Start with Python and a small DNA-sequence example.
• Does Population Growth Depend on Individual Mortality?
  Individual mortality affects a population’s finite rate of increase through survival, but fecundity, age structure, migration, and census timing also determine growth.
• What Is the Exponential Growth Equation for Bacteria?
  Use the bacterial exponential-growth equation to predict cell numbers from a starting population and doubling time, and learn when the model applies.
• How to Calculate Relative Fitness from Recapture Data
  Use recapture data to estimate survival while accounting for detection, then divide each group’s absolute fitness by a reference value to obtain relative fitness.
• Is Photosynthesis Faster Than Respiration?
  Photosynthesis often exceeds respiration in a well-lit, actively growing plant, but the balance changes with light, temperature, species, and time of day.
• How Do Alpha and Beta Glucose Differ in Starch and Cellulose?
  Starch and cellulose both contain glucose, but alpha versus beta bonds at carbon 1 give their chains different shapes, branching, and digestibility.
• Disruptive vs. Divergent vs. Diversifying Selection
  Disruptive selection favors both extremes within one population; divergent selection favors different traits in different environments.
• How Should Genus and Species Names Be Formatted?
  Format scientific names by capitalizing and italicizing the genus, lowercasing and italicizing the specific epithet, and following standard abbreviation rules.
• Where Does Moss Come From?
  Moss grows from spores or fragments, not from seeds or soil. Learn how its life cycle works and why it appears on damp surfaces.