4th one
they travel to go where the season's right, which'll give them the best resources
Check out this website http://science.jrank.org/pages/3421/Hummingbirds-Biology-hummingbirds.html
The zygote, a single cell, implants its self to the uterine wall and it developes into an embyro which is a cluster of cells.
It would be glycogen, after reading the article from the science learning hub.
True because excretory is like sweat and you sweat through your skin- more specifically the pores in your skin
