External skeleton is the correct answer. Hope this helps out !
This is an example le of commensalism.The burdock seeds benefit and the cow is unharmed.
LOCAL ENVIRONMENT ISSUE:
People dump a lot of trash in the sea, and the sea creatures living there goes through a lot of trouble to live with all the muck getting in them. Of course, don't write it like that in your assignment - you'll get told off for the straight forwardness.
Nucleases are the enzymes that are unique to the pancreas. These are enzymes which break down nucleic acids DNA and RNA into nucleotides. When these nucleotides reach the ileum, they are further degraded or digested into sugars, bases and phosphates. These nucleases are known as DNAase and RNAase
Other pancreatic enzymes such as amylase and protease are also produced by other digestive organs such as the salivary glands and the small intestine respectively. However no other digestive organ has been known to produce nucleases apart from the pancreas.
Nucleases are of two main types, namely exonucleases which cut off the end of a nucleotide and endonucleases which will cut out certain nucleotide sequences right in the middle of a nucleic acid.
Answer:
D, think of chemical changes. When iron rusts it is chemically changed. The other answers are a change in form or a property of iron.