Organisms that cannot make their own food and must obtain energy from external sources are called
a. autotrophs.
b. heterotrophs.
c. thylakoids.
d. plants.

Which of the following best describes the relationship between glucose and complex molecules such as hormones?

What must be done to breed dogs for a partical trait

Punnett squares are used to show possible combinations of alleles or to predict the probability of a trait occurring in offspring. an incomplete dominance cross is performed between a bird that is homozygous for red feathers and a bird that is homozygous for blue feathers. purple offspring result. then, two of the purple offspring are crossed. according to the punnett square for this cross, how many of the offspring from the second cross will have a feather color that results from incomplete dominance? 1 in 4 2 in 4 3 in 4 4 in 4