This preview shows page 1. Sign up to view the full content.
Unformatted text preview: ed at thos e wav elengths ? How would that affec t the number of aerotac tic bac teria
attrac ted to thos e parts of the alga? Finally , how would that affec t the ac tion s pec trum? Hin t 2. How does light intensity (number of photons) affect the amount of oxygen produced?
Engelmann’s ex periment demons trated that red light is effec tiv e at driv ing photos y nthes is , and thus ox y gen produc tion, in the alga he s tudied.
Now s uppos e Engelmann did an ex periment in whic h he illuminated an algal c ell with red light for 3 minutes and c ounted the number of bac teria
that aggregated near the c ell. Nex t, he repeated the ex periment but doubled the intens ity of the red light, i.e., he doubled the number of red
photons hitting the c ell.
Predict how the num ber of bacteria aggregating near the cell would change from the first experim ent to the second.
The number of bac teria aggregating near the c ell would inc reas e after doubling the intens ity of the red light.
The number of bac teria aggregating near the c ell would remain the s ame after doubling the intens ity of the red light.
The number of bac teria aggregating near the c ell would dec reas e after doubling the intens ity of the red light. ANSWER: se ssion.ma ste r ingbiology.c om/myc t/a ssignme ntPr intVie w? a ssignme ntI D= 2242937 11/41 13- 10- 13 Cha pte r 10 Correct
An ac tion s pec trum is ty pic ally plotted s o that the “ac tion” s hown on the y ax is is meas ured with an equal number of photons at eac h wav elength
of the v is ible s pec trum. But our s un does not emit equal numbers of photons at eac h wav elength.
Ins tead, the s un emits the mos t photons in the y ellow part of the s pec trum, with relativ ely fewer photons emitted in the red and v ioletblue parts of
the s pec trum. Thus , the red and v ioletblue regions of Engelmann’s ac tion s pec trum were meas ured with fewer photons than in the y ellow part of
the s pec trum.
To c orrec t for this , y ou hav e to c ons ider how inc reas ing the number of photons in the red and v...
View Full Document
- Spring '14