Experts in deer ecology generally agree that population sizes of deer that live in temperate climates are limited by winter snow. The deer congregate in ?yarding? areas under evergreen trees because venturing out to feed in winter is energetically too expensive when snowfall depths accumulate to above 40 cm. Deer often stay yarded until the spring thaw. Snow depth over 40 inches for more than 60 days results in high mortality due to starvation.  This observation best illustrates which of the following principles about factors that limit distribution of organisms?

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#Question id: 19281

#Unit 9. Diversity of Life Forms

A botanist discovers a new species of plant in a tropical rain forest. After observing its anatomy and life cycle, the following characteristics are noted: flagellated sperm, xylem with tracheids, separate gametophyte and sporophyte generations with the sporophyte dominant, and no seeds. This plant is probably most closely related to 

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#Question id: 2623

#Unit 2. Cellular Organization

Combinatorial control is a characteristic feature of ;

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#Question id: 10928

#Unit 7. System Physiology – Animal

A 40-year-old woman visits the clinic complaining of fatigue. She had recently been treated for an infection. Her laboratory values are RBC 1.8 × 106/μl, Hb 5.2 g/dL, hematocrit (Hct) 15, WBC 7.6 × 103/μl, platelet count 320,000/μl, mean corpuscular volume (MCV) 92 fL, and reticulocyte count 24%. What is the most likely explanation for this presentation?

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#Question id: 26922

#Unit 10. Ecological Principles

Which of the following are not the major  components of the ecological niche?

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#Question id: 3880

#Unit 3. Fundamental Processes

Which one of the following properties of the L-19 IVS ribozyme is not shared with enzymes that are purely protein?