BIO 305 Lecture Notes - Lecture 4: Null Hypothesis, Stoichiometry
Document Summary
How to determine limiting factors in biology: experiments to add hypothesized limiting factors, adding nutrients to growing organisms, adding carbon sources to growing, changing temperature, stoichiometric calculations. Adding n along (green arrow)= adding n and oc together (blue arrow) Adding oc alone > adding n alone. Adding p alone (red) or in any combination (yellow, pink, white) produced largest increase. All factors limiting, but strength of limit p>oc>n. If standard errors are overlapping then you cannot reject the null hypothesis. Limits to biological performance: resource limitation of plants in ecosystems across the globe. Hypothesis: nitrogen limits plants production rather than phosphorus. How general are the results that you get. Rrx= growth with added nutrient/growth control (-1) Rrx> 0 -- the growth was higher with added nutrient, factor limiting. Rrx=0 -- the growth was the same, no effect. Hypothesis of n limitation supported only in marine ecosystems. Nucleotides: the stuff of which dna/ rna are made of.
