Question

Activity
5.1
Let us take a small piece from an onion
bulb. With the help of a pair of forceps,
we can peel off the skin (called
epidermis) from the concave side (inner
layer) of the onion. This layer can be
put immediately in a watch-glass
containing water. This will prevent the
peel from getting folded or getting dry.
What do we do with this peel?
Let us take a glass slide, put a drop of
water on it and transfer a small piece
of the peel from the watch glass to the
slide. Make sure that the peel is
perfectly flat on the slide. A thin camel
hair paintbrush might be necessary to
help transfer the peel. Now we put a
drop of safranine solution on this piece
1ollowed by a cover slip. Take care to
avoid air bubbles while putting the
cover slip with the help of a mounting
needle. Ask your teacher for help. We
have prepared a temporary mount of
observe this slide
onion peel. We can
under low power followed by high
powers of a compound microscope.​

Answer 1

The basic microscopic unit of bone is an osteon (or Haversian system). ... Each osteon consists of a lamellae of compact bone tissue that surround a central canal (Haversian canal). The Haversian canal contains the bone's blood supplies. The boundary of an osteon is called the cement line.