996 past contests
Topic 52 · The dna double helix is held by hydrogen bonds, not ionic bonds (true/false)
Topic 10 · Both dsdna and dsrna form double helices, though of different conformations (true/false)
Topic 52 · G-c base pairs (3 hydrogen bonds) bind more strongly than a-t pairs (2 bonds) (true/false)
Topic 27 · Viruses can mutate, so the claim they can't is false (true/false)
Topic 27 · Viruses lack their own ribosomes, relying on the host's (true/false)
Topic 2 · The nucleolus as the site of ribosome assembly
Topic 2 · The phospholipid bilayer as the major component of the cell membrane
Topic 3 · Protein-digesting enzymes have no action on starch (true/false)
Topic 53 · Abo blood-type inheritance: a child's phenotype needn't match either parent's
Topic 5 · The stroma and thylakoid space as the two major chloroplast compartments
Topic 5 · Acetyl-coa entering the krebs cycle from the transition (link) reaction
Topic 11 · Riddle: vestigial structures, homologous remnants explained by evolution
Topic 45 · Applications of plant hormones in agriculture (auxins, cytokinins, gibberellins, ethylene, aba)
Topic 2 · Phospholipid structure and self-assembly into the selectively-permeable plasma membrane bilayer
Topic 5 · Problem of the day: physiological benefits of high-altitude training for athletes
Topic 11 · Why natural selection acts more intensely on prey than predators (survival stakes)
Topic 52 · Dna helicase unwinding double-stranded dna by breaking hydrogen bonds
Topic 18 · Nitrogen fixation making atmospheric nitrogen available to plants
Topic 18 · Why most cellular reactions require enzymes (activation energy, specificity, efficiency)
Topic 24 · Biological importance of seed dormancy