Cellular respiration is best associated with the Mitochondria
Specialised cells mean they have one specific job, for example cells in the alveoli (in the lungs) would be specialised to transfer oxygen into the blood. An unspecialised cell would be an embryonic stem cell which can become any cell to suit the needs of the organism, which is how a small cluster of cells in a zygote becomes a full human with all the organs and such.
Tropical ecosystems provide a more open weather and climate than temperate zone ecosystems. Many Tropical ecosystems have a moderate climate the mostly stays the same, which allows most animals in that habitat to have comfort, rather than migrating.
<span>Most children acquire a firm sense of gender identity by the age of three</span>