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.
You might also want to read about the life expectancy of birds. Most songbirds will lay an egg a day. They sit on their eggs for 12-14 days. The baby birds are able to leave the nest about 14 days later and can fly a few days after that. Robin eggs are a solid pale bluish-green. This is the most common egg you will find in your yard. The book shown below has many color photos of bird eggs.