Heterocyst-forming cyanobacteria differentiate highly specialized cells to provide fixed nitrogen to the vegetative cells in a filament. In the presence of a source of combined nitrogen such as nitrate or ammonium, Anabaena PCC 7120 grows as long filaments containing hundreds of photosynthetic vegetative cells.
Answer:
B. Smaller fragments travel faster and farther than larger fragments.
Explanation: Shorter molecules move faster and migrate farther than longer ones because shorter molecules migrate more easily through the pores of the gel. This phenomenon is called sieving. [2] Proteins are separated by charge in agarose because the pores of the gel are too large to sieve proteins.
The nucleotides in DNA contain four different bases, those of which being nitrogenous bases.
The four bases are:
1 - Thymine
2 - Cytosine
3 - Adenine
4 - Guanine
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