(b) Aphids are major pests of crops. Their population can be naturally controlled by predators and parasites.
(1) Explain why some crop farmers may be advised not to spray with pesticides when they
first see aphids on their crop.
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the speed increase from w to x due to increased gravity force

the speed decreases from x to y due to decrease in gravity

hydroxyl -oh

alcohols, always polar, can form hydrogen bonds with h2o molecules

carboxyl -cooh  

cargoxylic acids, has acidic properties which is a source of hydrogen ions, found in cells in ionized for with a charge of oh-1

carbonyl > co

ketone if within skeleton, aldehyde if group is at the end of skeleton, k & a may be structural isomers, it determines 2 sugars (ketose & aldose)

amino -nh2

amines, acts as a base, it can pick up h+ ions from surrounding solution, ionized with charge of 1+

methyl ch2

addition to rna/dna affects and gene expression

phosphate -opo3 ²⁻

organic phosphates, contributes to negative charge to, molecule that it is a part of, and potential to react with h20

sulfhydryl -sh

thiols, cross-linking stabilize the protein, and it is structure

c.more precipitation,but only when emission levels.

you should wear a lead protective shield when having teeth x-rays

hope i

-lavira : )