The Good, the Bad and the Neutral

A

B In most school lunchrooms, a common drink to go with lunch is milk, but it wasn’t until a few thousand years ago that humans could even digest milk past childhood. Most babies can digest milk without getting an upset stomach thanks to an enzyme called lactase. Up until several thousand years ago, that enzyme turned off once a person grew into adulthood — meaning most adults were lactose intolerant. Lactose is the part of milk that makes it difficult for people to digest milk. Now, thirty-five percent of people can digest milk without any problems.

C Bumps and scrapes are a normal part of childhood. For most kids, a tumble off a bike or a stray kick in a soccer game means a temporary bruise or a cut that heals with a scab. However, for kids with hemophilia, these everyday mishaps are cause for concern.Hemophilia is a disease that prevents blood from clotting properly. Clotting helps stop bleeding after a cut or injury. If clotting doesn't happen, a wound can bleed too much.

D

E Almond trees naturally make a compound that contains cyanide, a poison. To other organisms that would eat the almond, the compound makes the almonds taste bitter. This helped the almond trees make sure that their seeds were left alone to produce other almond trees. However, sometimes almond trees lose the ability to make this bitter compound. Not only are the almonds more delicious to different animals this way, the flower’s nectar doesn’t attract many pollinators. Humans have profited on this non-bitter almond tree, by farming almonds.

F