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What is DNA made of?

DNA is made of small subunits called bases that join together to form a long chain. The bases in each chain join to the bases in another chain to form a structure that looks a bit like a ladder, with each ch...
BN
Answered by Ben N. • Biology tutor
2978 Views

Please can you explain what a heart attack is and how it can occur?

The heart is an organ made of muscle in the centre of the chest. It's role is to pump oxygenated blood around the body to enable our functions to be carried out. During a heart attack, a section of the heart...
VG
Answered by Vijay G. • Biology tutor
3443 Views

Discuss the reactivity benzene, chlorobenzene, toluene and phenol in electrophillic aromatic substitution

Phenol > Toluene > Benzene > Chlorobenzene. The reactivity of the ring is dependant on how electron rich it is, as this determines the extent to which the (positively charged) electrophile can attac...
JM
31563 Views

Find the number of solutions x in [0,2pi) to the equation 7sin x +2(cos x)^2 =5.

The problem seems to be hard as the equation involved both cosx and sinx But we can relate the two as (cosx)^2 + (sinx)^2 = 1, so we can rearrange this as 0 = 2(sinx)^2 - 7sinx + 3. This quadratic in sinx ha...
JR
Answered by James R. • MAT tutor
3253 Views

Explain how SSRI's ares used in the treatment of depression.

SSRIs or selective serotonin reuptake inhibitors can be used to treat depression. They are used as they inhibit the reuptake of the neurotransmitter, serotonin, in the presynaptic cell. This increases the le...
TS
Answered by Tiff S. • Psychology tutor
2413 Views