Un niño que ha enfermado de paperas o varicela, no desarrollará estas enfermedades en una segunda oportunidad, porque:

I. la piel, mucosas y lágrimas impiden el ingreso de los microbios.

II. en el primer contacto adquirió anticuerpos.

III. interviene la inmunidad Adaptativa, la cual presenta “memoria”.

IV. su sistema defensivo está preparado frente a una segunda exposición

a. I y II son correctas

b. III y IV son correctas

c. II, III y IV son correctas

d. I, II y III son correctas.

Diego conducted an experiment to find out what kind of ball bounces the highest when dropped from a five-foot platform. he used a golf ball, a tennis ball, and a soccer ball. he dropped each ball from the balcony once. diego recorded his observations after each drop. what can diego do to best improve the reliability of his results? a) drop each ball from the platform three more times b) record his observations in more than one unit c) write at least two scientific questions after the experiment is complete d) share his results with other people who have done similar experiments you for the !

Apuppy’s tendency to chew is inherited through which of the following? a. through learned behavior b. through genes c. through seasonal cycles d. through hibernation

Recently, crops of vegetables such as lettuce and green onions have been contaminated, while they are still on the farm, with bacteria that cause food poisoning. how will science influence the way the government responds to prevent an increase in food-borne diseases? because science has shown that lettuce and green onions are not nutritionally valuable, the government may pass laws that ban the sale of lettuce and green onions. because science has shown that there is no way to prevent bacterial contamination, the government may pass laws that punish businesses that buy lettuce and green onions. because science has shown that the washing of hands prevent the spread of infectious diseases among people, the government may pass laws that require hand washing by everyone who handles food. because science has shown there are ways to find the source of the contamination, the government may pass laws that require farm practices that reduce the contamination of lettuce and green onions.