Questão 30 - UEFS Caderno 1 2016/1

TEXTO:

[1]   Scientists may be on top in the battle against

bedbugs. These insects are one of the most difficult to

control. But research, from the journal Scientific Reports,

could help scientists to develop new, improved control

[5] methods.

  They feast on our blood while we sleep — leaving

itchy, red welts as their calling card. Bedbugs are an

insect that many would like to see the back of. But in

North America, Europe and Australia, infestations are on

[10] the rise — and our insecticides are losing their bite.

  Researchers at the University of Kentucky in the

US have found 14 genes associated with resistance to

these chemicals. They’re causing a number of biological

changes in the bedbugs. These include the development

[15] of a thicker skin that stops the poisons from penetrating

and mutations within the insects’ bodies that prevent the

toxins from hitting the nervous system.

  The genes linked to these changes are active in

the insect’s tough outer shell - creating a formidable first

[20] line of defense. These findings could help scientists to

develop new insecticides that could either turn these

genes off or bypass the pest’s molecular shields. But

until these substances are developed, exterminators are

having to resort to more primitive tactics.

MORELLE, Rebeca. Disponível em: <www.bbc.co.uk/worldservice/ learningenglish/language/wordsinthenews/2013/03/13 0315_witn_ bed_bugs.shtml>. Acesso em: 2 fev. 2016.

The only alternative in which the word or expression from the text has not been correctly defined is