Which of these is a way the immune system works with other body systems? A. T cells make chemicals that control blood pressure.
B. B cells boost memory in the brain.
C. The spleen makes digestive enzymes.
D. The spleen filters pathogens from blood.

What processes take place before the mature mrna exits the nucleus?

Which of the following observation darwin shape his concept of descent with modification? a) species diversity declines farther from the equator. b) fewer species live on islands than on the nearest continents. c) birds live on islands located farther from the mainland than the bird's maximum nonstop flight distance. d) south american temperate plants are more similar to the tropical plants of south america than to the temperate plants of europe. e) earthquakes reshape life by causing mass extinctions.

When a population split into two subgroups what is most likely to cause the subgroups to develop different traits?