The sugar-phosphate backbone of DNA is held together by covalent bonds.     The strands of DNA are joined by hydrogen bonds (H-bonds) between the nitrogenous bases o â¦ n either side. Adenine is joined to Thymine by 2 H-bonds. Cytosine is joined to Guanine by 3 H-bonds.
The mother will leave the nest and the newly hatched chicks sometimes for long periods of time to eat, drink or take a bathroom break. In some species the father will then take over nest duties, but in hummingbirds, itâs up to the mother to tend the eggs and the babies.
The Anna's hummingbird typically lays 2 eggs each time she broods. The tiny white eggs are about 0.5 inches long and 0.4 inches wide. The incubation period typically is 16 days, but can range from 14 to 19 days in length. The baby hummingbirds are born with almost no downy feathers and their eyes are closed.