QUE S T b)
1
A supermarket chain advertises that its plastic carrier-
bags are 'environmentally friendly'. These bags are
made from polythene and contain added starch. A
student decided to find out if the claim is true. In the
investigation the student buried a piece of plastic from
the bag in a pot of soil and left it for one month. When
the plastic was dug up there were many small holes in
it.
The drawings show the plastic, as seen through a
microscope,
before and after being buried.
Starch
Hole
3
Plastic buried for 1 month
Plastic before being
buried
a) Explain, as fully as you can, the process that caused
the holes to appear in the plastic.​

Ms. w, a 21-year-old woman, came into a clinic after suffering a deep laceration on her foot while walking barefoot around her yard. the wound was cleaned, sutured, and bandaged, and she was released to return home after receiving tetanus antitoxoid. within 72 hours, the wound area was red and swollen, the suture line was dark in color, and it was accompanied by severe throbbing pain. ms. w had a high fever, her heart felt like it was racing, and she was finding it hard to concentraten even on simple tasks. she returned to the clinic and was immediately taken to the hospital. following lab tests, a diagnosis of acute necrotizing fasciitis was made. discussion questions 1. explain why ms. w. received a tetanus antitoxoid before leaving the hospital. (see chapters 3 and 4, infection and passive immunity.) 2. explain how acute necrotizing fasciitis developed in this case and the pathophysiology involved. (see acute necrotizing fasciitis.) 3. what is the potential outcome for ms. w if antibiotic drugs do not reduce the infection quickly?