- Life Sciences
a small, circular opening in the exoskeleton of insects that allows air to enter the insect's body via the trachea.
two or more forms of a particular chemical element, that have the same number of protons in the...
the thin moist surface across which gaseous exchange occurs.
coiled thread-like structures of DNA and histone, which is a protein, in the cell nucleus. They...
structure in animal cells thought to form the spindle fibres during cell division.