A culture of cells is given 3H-thymidine for 30 minutes; then a sample of the cells is fixed and examined by autoradiography. It is found that:

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#Question id: 12019

#Unit 10. Ecological Principles

Chickadees were given an opportunity to store seeds in 72 possible storage sites consisting of holes drilled in small trees that had been placed in an aviary. Typically, the seeds were placed in only 4 or 5 storage sites. The chickadees were then removed from the aviary, the seeds removed from the storage sites, and each hole covered. A day later, the chickadees were returned to the aviary and they spent nearly 5 times as long pulling at the covers on storage sites than at the covers on sites where they had not stored food. This experiment indicates that chickadees

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#Question id: 26928

#Unit 10. Ecological Principles

Hutchinsonian niche is proposed by G. Evelyn Hutchinson, that basically based on

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#Question id: 24573

#Unit 10. Ecological Principles

Calculate the finite rate of increase, if ecologists count the number of birds in the population, N0= 100, the next year ecologists count 110 birds in the same population, 

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#Question id: 1965

#Unit 4. Cell Communication and Cell Signaling

In some insects, such as Drosophila, fungal cell wall elements can activate the protein Toll. What is Tollʹs function?

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#Question id: 24548

#Unit 9. Diversity of Life Forms

Many phenotypic traits are genetically variable within species, they can readily evolve by

a. natural selection

b. adaptation

c. genetic drift

d. mutation