Practise IB Biology SL B4.1 by linking organism distribution and adaptations to abiotic limits, tolerance ranges, climate and biome conditions.
41 questions in this syllabus scope, with question parts counted together.
141 papers analysed · Tagging incomplete
Define habitat, population, community and ecosystem.
Avicennia officinalis is a tree species that is adapted to live in mangrove swamps. Salt glands can be seen in the micrograph of a transverse section of an A. officinalis leaf.
How does A. officinalis benefit from this adaptation?
The glands provide nitrates for amino acid synthesis as mangrove soils are nitrogen-deficient.
The salt in the leaves attracts predators to eat the leaves.
A high concentration of salt in the glands allows absorption of water into the leaf cells.
The glands secrete salt to keep cytoplasmic concentration suitable for metabolic processes.
The life cycle of the mosquito (Aedes aegypti) starts as a larva, then moves to the pupa stage, after which it moves to the adult stage. The influence of pH on mosquito larval development was measured. On the graph, 1.0 indicates that all individuals are at the larval stage and 0 indicates that all are pupae.
What can be concluded about the effect of pH on larval development from this graph?
All mosquito larvae developed into pupae by day 15 at both pH values.
pH has no effect on larval development of the mosquito.
On day 10 , there are more pupae at pH 8 than at pH 6 .
Mosquito larvae developed faster at pH 6.
Nisin, is a naturally occurring polypeptide, that is used in the food industry to prevent the growth of food-borne pathogens such as Listeria monocytogenes. The pathogen was grown at three different nisin concentrations using a range of pH values and NaCl concentrations. Dark shading shows visible growth of bacteria after 48 hours of incubation and light shading shows areas where bacterial growth was inhibited but the bacteria were not killed, clear areas show where bacteria were killed.
Deduce the highest pH at which all L. monocytogenes are killed.
Reef-building corals are an association between two organisms: coral polyps and Zooxanthellae.
State one limiting factor on Zooxanthellae which affects coral reef formation.
A graph of abiotic factors needed for biomes to develop is shown. Which label identifies temperate forest?
Distinguish between the biosphere and biomes.
Outline the typical yearly temperatures and vegetation found in a named biome.
The desert cottontail (Sylvilagus auduboni) is a rabbit that lives in North American deserts.
Suggest one adaptation of the cottontail that helps it to survive in desert conditions.
One additional mark is available for the construction of your answer.
