Zadanie 7, Paper 2, listopad 2024, TZ2, Biologia IB SL

(a) Cohesion keeps water molecules together, contributing to surface tension or continuous water columns. ✔

Adhesion to surfaces supports movement of water through plant tissues. ✔

High latent heat of vaporization permits evaporative cooling. ✔

High specific heat capacity buffers temperature changes. ✔

Solvent action allows transport of polar substances or reactions in aqueous solution. ✔

Transparency permits underwater photosynthesis. ✔

(b) Some sufficiently small molecules can diffuse down their concentration gradient through the bilayer. ✔

Facilitated diffusion moves particles down a gradient OR uses channel/carrier proteins. ✔

Active transport moves particles against a gradient OR uses protein pumps. ✔

Diffusion does not require ATP OR active transport uses ATP. ✔

(c)

Human activities drive much of the increase. ✔

Combustion of fossil carbon or deforestation increases atmospheric carbon dioxide. ✔

Carbon dioxide absorbs outgoing long-wave infrared radiation, enhancing the greenhouse effect. ✔

Global temperatures rise. ✔

Oceans absorb heat and become warmer. ✔

Ice melt can remove polar habitat, sea level can rise, or warming can cause coral bleaching. ✔

Ocean currents or regional climate patterns may change. ✔

Atmospheric carbon dioxide dissolves in seawater. ✔

Dissolved carbon dioxide increases acidity or lowers pH. ✔

Carbonate-ion availability decreases. ✔

Calcifying organisms may struggle to build skeletons or shells. ✔

Species distributions, food webs, abundance or biodiversity can change. ✔

Quality of communication: clear on first reading, concise and free from unnecessary repetition or irrelevant material. ✔

Part (a): any 4 property–biological-use links, maximum 4. Part (b): any 4 distinct points, maximum 4; vesicle mechanisms are not required. Part (c): any 7, maximum 7. Award 1 independent communication mark. Maximum 16.