<span>The first two tenets of the Cell theory were postulated by Schleiden and Schwann at the first half of the 19th century. Those tenets are that "all organisms are composed of one or more cells" and that "the cell is the basic unit of life". In 1855, Rudolf Virchow added the third tenet "Omnis cellula e cellula" which means that "all cells come from cells". In other words, cells can be formed only in the division of other cells.</span>
Answer answer answer answe
Answer:
The correct answer is option - e. all of the above are useful traits.
Explanation:
A cloning vector is a small segment of DNA that can be established stably in an individual organism and able to internalize a foreign DNA for cloning purposes. The cloning vector could be taken from different organisms such as plasmid of a bacterium, or DNA from a virus. A cloning vector must possess some characteristics -
The cloning vector must be self-replicating ability in the host cells, it should be small in size with restriction site for the restriction endonuclease enzymes in it. The replication character of the vector should not interfere with the internalized DNA fragment. The presence of marker genes in the vector is also a property that is helpful in identifying of recombinant cells.
Thus, the correct answer is option - e. all of the above are useful traits.
<h3><u>Answer;</u></h3>
U Boat
<h3><u>Explanation</u>;</h3>
- U-boat is an anglicised version of the German word U-Boot. It is the shortening of underseaboat. It describes the submergible watercraft that they developed and used extensively for world war i.
- German began to employ U-boats to break a stalemate at sea. U-boats were traveling under water ships.
- They were used to sink British supply ships with no warning. Due to the British blockade, with it's fleet bottled up, Germany had to use U-Boats to get at the British lifeline across the Atlantic.
