A scientist observes a bee and a bird on a cool spring morning, when the temperature is 49°F. The bird immediately leaves its nest. It flies around and starts looking for insects to eat. The bee remains still, sitting in the sun on a leaf. After an hour, the temperature has risen to 57°F. The bee begins to fly around and collect pollen from flowers. Explain why the bee and the bird behave differently as the temperature changes.

Which of these is true of the cytoplasm of an unfertilized egg? a. it is an unevenly distributed mixture of mrna, proteins, organelles, and other substances. b. it does not contain substances that are important in directing development. c. these substances are supplied by the sperm. d. it does not contain substances that are important in directing development. e. development is directed solely by the surrounding cells. f. it is a homogeneous mixture of mrna, proteins, organelles, and other substances. g. it does not contain substances that are important in directing development. h. these substances are produced by the dna of the fertilized zygote.