Which immune system cells are attracted to the chemicals secreted by helper T cells? memory cells and B lymphocytes cytotoxic T cells and B lymphocytes macrophages and cytotoxic T cells O cytotoxic T cells and memory cells​

i think it is dna, i'm not totally sure but i think it might be.

if your own plato the answer is b. the fern transitioned from sporophyte generation to gametophyte generation.

true

explanation:

answer: andy garner, a 17-year-old who decided to become a human guinea pig in 1965 and go without sleep for 11 days. by the second day his eyes had already stopped focusing, and he lost the ability to identify objects by touch. by day three he was moody and uncoordinated and by the end he had trouble with short term memory and had even started hallucinating.

and a rare genetic mutation called fatal familial insomnia, where people can’t sleep at all, gets progressively worse over months or years and leads to dementia and death.

a devoted soccer fan died after staying awake 48 hours to watch the world cup, she said. ‘while his untimely death was due to a stroke, studies show chronically sleeping fewer than six hours a night increases stroke risk by 4 1/2 times compared with those getting a consistent seven to eight hours.'

*shorten it up as your wish*

(i have divided it into 3 simple paragraphs)