There are at least three different types of companion cells in the minor veins of mature, exporting leaves. Which of the following statements about these companion cells is CORRECT?

 a.) transfer cells are transport sugars enter the apoplast during the movement of sugars from mesophyll cells to sieve elements. Transfer cells transport sugars from the apoplast to the symplast of the sieve elements and companion cells in the source.

 b.) the numerous mitochondria in companion cells may supply energy as ATP to the sieve elements

 c.) Ordinary companion cells can function in either symplastic or apoplastic short-distance transport in source leaves, depending in part on plasmodesmatal frequencies

 d.) Intermediary cells, by contrast, function in symplastic transport of sugars from mesophyll cells to sieve elements

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#Question id: 1990

#Section 2: General Biology

B cells interacting with helper T cells are stimulated to differentiate when

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#Question id: 293

#Section 2: General Biology

Which of the following types of bonds or interactions between lipid hydrocarbon tails is responsible for lipids forming a membrane bilayer or membranous vesicles in water

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#Question id: 13098

#Section 7: Recombinant DNA technology and Other Tools in Biotechnology

You are a scientist who is using genomics to currently study a new bacterial species that no one has ever studied before. The following sequence is a piece of DNA within the coding region of a gene that you have recently sequenced.

 

How many of the 6 potential open reading frames are actually open in this sequence shown above?

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#Question id: 3939

#Section 3: Genetics, Cellular and Molecular Biology

When used to describe the RNA polymerases, the term “processive” refers to:

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#Question id: 15905

#Section 6: Plant, Animal and Microbial Biotechnology

Meristemoids are considered to arise in areas that accumulate polysaccharide, which is believed to serve as an energy source for shoot bud differentiation