Biodiversity and populations practice
QCE Biology · Original practice questions with worked solutions
All biodiversity and populations practice questions
39 original questions · Page 2 of 2
- Q92 · Original practice · 9 marksBiodiversity and populationsA researcher marks 30 frogs and releases them. In a later capture of 45 frogs, 9 are marked. These 45 frogs comprise 9 AA, 24 Aa and 12 aa individuals at one diploid locus. Assume a closed, well-mixed population and a genotype-representative sample. After both captures, 20 AA frogs immigrate; no other population changes occur.
- Q98 · Original practice · 8 marksBiodiversity and populationsBefore a wildlife corridor opens, researchers mark 54 frogs in an isolated wetland. A second capture contains 75 frogs, 18 marked. Assume Lincoln-index conditions are met. A separate representative genetic sample estimates A frequency as 0.20 at one diploid locus. After the capture study finishes, the corridor allows 15 AA frogs to join the breeding populati…
- Q101 · Original practice · 1 markBiodiversity and populationsTwo beetle groups live in the same forest and have almost identical appearances. Each group breeds successfully within itself, but crosses between the groups consistently produce sterile offspring. Which conclusion is most consistent with the biological species concept?
- Q102 · Original practice · 1 markBiodiversity and populationsIn a capture–recapture study, marks are retained and the population is closed. Marked animals become less likely than unmarked animals to enter a trap. With first-capture number M and second-capture number n unchanged, the Lincoln-index estimate is most likely to
- Q103 · Original practice · 1 markBiodiversity and populationsTwo samples each contain three equally abundant species. Sample P contains 5 individuals of each species; sample Q contains 30 of each. Use . Which statement is correct?
- Q104 · Original practice · 1 markBiodiversity and populationsA reserve contains 75% woodland and 25% wetland. An investigator can place 24 quadrats and wants proportional stratified random sampling. Which plan meets this requirement?
- Q105 · Original practice · 1 markBiodiversity and populationsA census interval begins with 280 birds and ends with 310. During the interval there are 44 deaths, 12 immigrants and 18 emigrants. How many births occurred?
- Q119 · Original practice · 6 marksBiodiversity and populationsEqual-sized invertebrate samples are taken from two ponds using the same technique. Use . The species counts are shown.
- Q120 · Original practice · 5 marksBiodiversity and populationsTwo teams independently sample the same uniform meadow at random positions. Team S uses ten 0.25 m² quadrats and counts 20 plants in total. Team L uses ten 1.00 m² quadrats and counts 80 plants in total. The meadow area is 600 m².
- Q121 · Original practice · 5 marksBiodiversity and populationsA 5000 m² reserve contains dry habitat covering 70% of its area and wet habitat covering 30%. Equal numbers of random quadrats are placed in the two strata. Their mean plant densities are 2 plants m⁻² in dry habitat and 12 plants m⁻² in wet habitat. Treat these as representative density estimates.
- Q122 · Original practice · 5 marksBiodiversity and populationsA capture–recapture estimate uses M = 50, n = 80 and m = 16. An independent complete census later shows that the population was 500 during both capture sessions. All marks remained visible. Marked animals had been released beside baited traps and returned to those traps more often than unmarked animals.
- Q123 · Original practice · 6 marksBiodiversity and populationsThe curves show cumulative plant-species counts from randomly located equal-sized quadrats in habitats X and Y. Within each habitat, no previously recorded species is removed from the cumulative total.
- Q124 · Original practice · 5 marksBiodiversity and populationsSeedlings of one species are grown in a controlled experiment with two maintained soil-moisture levels and two light treatments. Each treatment starts with 30 seedlings and is repeated six times. Other conditions are held similar. The table gives mean survivors after four weeks.
- Q125 · Original practice · 4 marksBiodiversity and populationsBefore logging, the tallest vegetation stratum consists of 36 m trees with 55% foliage projective cover. After logging, the remaining tallest trees are 8 m high with 40% cover. A 3 m shrub layer has 85% cover. Use the supplied Specht excerpt; all cover values lie away from boundaries.
- Q126 · Original practice · 6 marksBiodiversity and populationsA closed population is monitored in a habitat with limited food. Extra food becomes continuously available on day 10 and remains available. The graph shows the response; no other condition is deliberately changed.