A-level OCR Biology Paper 2 Unofficial Mark Scheme - 11/06/18Watch
Serial dilution : 6 x 10^7
differnce between the stupid anaimal :big ears
-ATP has three phosphates & the nucleotide only has one
-ATP contains the base Adenine & the nucleotide contains the base Guanine
-ATP contains a ribose sugar & the nucleotide contains a deoxyribose sugar
30 degree got to stable phase (peak growth) faster/exponential phase was shorter/faster than 20 degree sample (it took less hours)
Reason - High temperature so increased enzyme action, nutrients used faster
30 degree sample begun death phase faster than 20 degree
Reason - 30 degree sample used up nutrients faster, not enough to support growth.
Possible additional reason - 30 sample/Flask 2 had greater amount of bacteria, greater amount of waste products halting further growth/pH of broth too high killing bacteria faster than they can divide
I wrote more but I can't remember, idk but I doubt they'll get any marks.
Wild type variant 6 marker (very brief overview) - I took this question to be a maintaining biodiversity question in disguise
Can't remember the Q but I recall speaking about mono-culture being exposed to a pathogen all being inbred have similar resistance to pathogens, if one is affected, they're all affected.
Spoke on halted genetic drift, low genetic diversity, natural selection halted, evolution doesn't occur due to human interaction
(due to the first point) Loss of economical profits for countries that rely on such cash crops, social factors such as enjoying aesthetics, ecological reasons such as modified plants having competitive advantage and possibly having genes capable of eliminating competition and possibly harming organisms that feed on them due to toxins produced.
I waffled a lot but idk what the mark scheme could've said. This was the hardest question in the exam imo due to how vague the question seemed to me at least.