The herbaceous plant Achillea lanulosa is widespread in the Northern Hemisphere. Phenotypic variation in the species has been extensively studied along an altitudinal gradient from sea level to over 3,000 meters. In California there is conspicuous variation in  height; alpine plants are only several centimeters tall  while  those in  the San Joaquin Valley may reach a height of 1.8 meters. Adaptation to different local environments also results in variation in physiological processes such as photosynthetic rate, resistance to cold, and the timing of dormancy.

The morphological variation shown by Achillea lanulosa illustrates

#Question id: 19878

#Unit 13. Methods in Biology

#Question id: 11447

#Unit 7. System Physiology – Animal

The correct sequence of sensory processing is ________.

#Question id: 10973

#Unit 7. System Physiology – Animal

An 11-year-old premenstrual female presents with a painful knee after mild trauma. Upon further evaluation you observe soft tissue bruises. The child is an orphan and there is no family history. The foster mother reports no other problems. The aPTT is prolonged and the PT is normal. A complete hematologic workup would yield

#Question id: 24152

#General Aptitude

#Question id: 5804

#Unit 8. Inheritance Biology

The gene that is mutated in cases of cystic fibrosis encodes an ion transporter protein normally expressed in the respiratory and digestive tracts along with other locations. Individuals homozygous for the most common mutation in this gene (ΔF508) died at very early ages prior to the advent of advanced medical intervention. Despite this, the mutation exists at relatively high frequency in populations of European descent. One potential explanation is that heterozygotes for such mutations may be relatively immune to the lethal effects of diseases such as typhoid fever. Which statement below is most accurate?