A farmer uses triazine herbicide to control pigweed in his field. For the first few years, the triazine works well and almost all the pigweed dies; but after several years, the farmer sees more and more pigweed. Which of these statements explains why the pigweed reappeared?

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#Question id: 28494

#Unit 5. Developmental Biology

 Which of the following is the major active factor in the ZPA?

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#Question id: 32219

#Unit 2. Cellular Organization

The transferrin dimer carrying two bound atoms of Fe³⁺, called ferrotransferrin, binds to the transferrin receptor at:

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#Question id: 12802

#Unit 10. Ecological Principles

In  which  community  would  organisms  most  likely  have  adaptations  enabling  them  to  respond  to  different photoperiods?

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#Question id: 278

#Unit 1. Molecules and their Interaction Relevant to Biology

DNA wraps around an octamer of histones to form bead-like structures called ________.

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#Question id: 2842

#Unit 2. Cellular Organization

Epigentic code for inactive X chromosome have post-translational modifications characteristic of other regions of heterochromatin as