Having been through it, I know it doesn't quite come out that way. Hair is always in three simulaneous cycles: fast growing, dormant and goind dormant. Obviously, if those three cycles appeared in clumps, your hair would grow unevenly and it doesn't. When it comes out, the fast growing goes first, the the going dormant and, sometimes, the dormant. I looked like pigpen as I left the air terminal during a stiff breeze with clouds of hair floating behind me. I went to the barber's the next day and had it all taken off. Eventually, I had a chrome dome. I actually liked it (except the loss of eyelashes and eyebrows meant there wasn't anything to keep the sweat out of my eyes!) You even lose the hairs in your nose and ears!
Not all forms of chemo cause hair loss. A few just cause thinning and some cause no hair loss at all. If you are approaching chemo, don't let the loss of hair scare you. The only straight head in a family of curlies, mine came back in tight little curls! I called it my $3800 perm. A friend's came back a rich red, in loopy curls.
If you are getting ready to do chemo, skip the onions, especially cooked ones. The sulphur compound prohibits the creation of red blood cells AND contributes significantly to nausea.
I skipped the wig. I bought a few scarves and this great velvet rasta hat for the sun (which I lined with a rich, thick terry face cloth!) but, as soon as people grew comfortable with the chemo me, the scarves came off and the skin was in. The big earrings and make-up the CS suggests just made me look like a sad fortune teller so I skipped those, too.
Eleven years past. It was worth being bald for a few months one summer.