Hydrogen bonds<span> are much weaker than covalent bond because of its bond is formed through fundamentally electrostatic interactions.
Hydrogen bonds happen due to dipole-dipole attraction while covalent bonds happen when valence electrons are shared.
Reasons why complementary nucleotides across the double-stranded dna bond together using hydrogen bonds rather than covalent bonds are (1) the distance between two strands, (2) size of the bases, (3) geometry of each base.</span>
<span>Protein</span>
<span>Cilia and flagella are made up of microtubules covered by
plasma membrane and they projection from the cell. Thus, cilia are flagella are
motile and designed to move substances over or around the cell and they can as
well move the cell itself. In eukaryotes, they are conserved in their polypeptide
composition, structure and function as motile and sensory organelles.</span>
Answer:
The answer for the blank is= Gene
Acetylcholine is the neurotransmitter important for muscle contraction as it binds to receptors on the membranes of muscles and cause the membranes to open channels for movement of calcium and sodium ions
