Which trait, dominant or recessive, will be expressed if an organism has one dominant allele and one recessive allele? A) Only the dominant trait will be expressed.
B) The organism will lack the trait completely.
C) Only the recessive trait will be expressed.
D) Both the dominant and recessive traits will be expressed.

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.