The recessive mutant allele that causes cystic fibrosis is much more frequent in Caucasians population than in other world populations. Some scientists believe heterozygotes must have had a survival advantage during plagues such as cholera that occasionally swept through this population. What concept does this illustrate?

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#Question id: 12568

#Unit 10. Ecological Principles

Which of the following would a landscape ecologist consider in designing a nature reserve? 

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#Question id: 5761

#Unit 8. Inheritance Biology

E. coli cells were spread on an agar plate, producing 1000 colonies.  The colonies are replica plated on two agar plates containing the antibiotic kanamycin and one agar plate without antibiotics.  All of the colonies are able to grow on the agar plate without antibiotic but only 4 colonies are able to grow on each of the agar plates containing kanamycin.  You notice that the four colonies that grew on each of the kanamycin containing plates are in the exact same position.  This demonstrates

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#Question id: 23870

#Unit 13. Methods in Biology

Which of the following are probably siblings?

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#Question id: 15740

#Unit 5. Developmental Biology

The position of the testis-determining gene was narrowed down to a 35,000-base-pair region of the:

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#Question id: 28787

#Unit 2. Cellular Organization

Phalloidin isolated from Amanita phalloides, binds at the interface between subunits in F-actin involves___