The two strands of a DNA double helix are held together by _____ that form between pairs of nitrogenous bases

a. ionic bonds
b. covalent bonds
c. hydrophilic interactions
d. S—S bonds
e. hydrogen bonds


Ans: hydrogen bonds

Biology & Microbiology

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A. "thymus glands, where naive B and T cells encounter antigens and become activated." B. "lymph nodes, where naive B and T cells encounter antigens and become activated." C. "lymph nodes, where T-cell receptor genes are rearranged as T cells mature." D. "spleen, where hematopoietic stem cells produce lymphoid and myeloid progenitors."

Biology & Microbiology

The nucleolus is a highly active region of the nucleus that is required for synthesis of ribosomes.

Answer the following statement true (T) or false (F)

Biology & Microbiology

Soil particles composed of decomposing organic matter are called ____

a. sand b. humus c. silt d. clay e. mineral

Biology & Microbiology

What is post-transcriptional gene regulation?

a. regulation after translation b. regulation when the DNA is uncoiled and loosened at the nucleosomes to bind transcription factors c. regulation when RNA is processed and exported to the cytoplasm after it is transcribed d. regulation when RNA is translated to protein

Biology & Microbiology