Biology · May / June 2023 · Paper 41 · Question 4

any six from:

LIGHT

(B and C as light intensity increases) the rate (of photosynthesis) increases and remains constant / AW ;

rates (of photosynthesis) are the same at low(est) light intensities ; light provides energy (for photosynthesis) ;

where the line rises / initially, light intensity is, limiting / the limiting factor ;

line(s) / rate, levels off where light intensity is not limiting ;

in B light intensity becomes limiting at higher light intensity than C / ora ;

CARBON DIOXIDE

Idea that line C levels off, at a lower rate (of photosynthesis) / lower light intensity ;

carbon dioxide (concentration) is, lower for C / 0.04% vs 0.4% ; carbon dioxide is, reactant / substrate / raw material / needed, for photosynthesis ;

in C carbon dioxide is a limiting factor at a lower light intensity / in B carbon dioxide is a limiting factor at a higher light intensity ; TEMPERATURE

idea that temperature is limiting for B at high light intensities ;

O2 ;

any four from:

(glucose) used, in respiration / to provide energy / to release energy / as an energy store ;

(glucose) converted to / stored as, starch ;

(glucose) converted to sucrose ;

sucrose for, translocation / transport (in the phloem) / sent to sink(s) ; (glucose / fructose / sucrose) in nectar ;

(nectar) to attract, insects / pollinators ;

(glucose / fructose / sucrose) in fruits (to attract animals) ;

(glucose) converted to cellulose ;

cellulose to build cell walls ;

lignin for cell walls ;

used to make, amino acids / fatty acids ;

AVP ;