All animals have eukaryotic cells, surrounded by a characteristic extracellular matrix composed of collagen and elastic glycoproteins. This may be calcified to form structures like shells, bones, and spicules. During development, it forms a relatively flexible framework upon which cells can move about and be reorganized, making complex structures possible. In contrast, other multicellular organisms, like plants and fungi, have cells held in place by cell walls, and so develop by progressive growth. Also, unique to animal cells are the following intercellular junctions: tight junctions, gap junctions, and desmosomes.
How are cells held in place in plants and fungi?
cell walls

Urban AC is a form of AC music geared towards adult African-American audiences, and therefore, the artists that are played on these stations are most often black, such as Des'ree, whose album I Ain't Movin' was massively popular amongst both African American audience as well as the wider national audience.
What age group is Urban AC focused towards?
adult

Time travel is the concept of moving backwards or forwards to different points in time, in a manner analogous to moving through space, and different from the normal "flow" of time to an earthbound observer. In this view, all points in time (including future times) "persist" in some way. Time travel has been a plot device in fiction since the 19th century. Traveling backwards in time has never been verified, presents many theoretic problems, and may be an impossibility. Any technological device, whether fictional or hypothetical, that is used to achieve time travel is known as a time machine.
A time machine is known as any technological devise that is used for what purpose?
to achieve time travel